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Sample records for fence lizards sceloporus

  1. Effects of inorganic lead on Western fence lizards (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    Salice, Christopher J., E-mail: chris.salice@ttu.ed [US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010 (United States); Suski, Jamie G., E-mail: jamie.suski@ttu.ed [US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010 (United States); Bazar, Matthew A., E-mail: matthew.bazar@us.army.mi [US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010 (United States); Talent, Larry G., E-mail: larry.talent@okstate.ed [Oklahoma State University, Department of Natural Resource Ecology and Management, Stillwater, OK 74078 (United States)

    2009-12-15

    Although anthropogenic pollutants are thought to threaten reptilian species, there are few toxicity studies on reptiles. We evaluated the toxicity of Pb as lead acetate to the Western fence lizard (Sceloporus occidentalis). The acute lethal dose and sub-acute (14-day) toxicity studies were used to narrow exposure concentrations for a sub-chronic (60-day) study. In the sub-chronic study, adult and juvenile male lizards were dosed via gavage with 0, 1, 10 and 20 mg Pb/kg-bw/day. Mortality was limited and occurred only at the highest dose (20 mg Pb/kg-bw/d). There were statistically significant sub-lethal effects of 10 and 20 mg Pb/kg-bw/d on body weight, cricket consumption, organ weight, hematological parameters and post-dose behaviors. Of these, Pb-induced changes in body weight are most useful for ecological risk assessment because it is linked to fitness in wild lizard populations. The Western fence lizard is a useful model for reptilian toxicity studies. - The Western fence lizard, Sceloporus occidentalis, is sensitive to Pb and is a useful laboratory model for ecotoxicological testing of reptiles.

  2. Effects of inorganic lead on Western fence lizards (Sceloporus occidentalis)

    International Nuclear Information System (INIS)

    Salice, Christopher J.; Suski, Jamie G.; Bazar, Matthew A.; Talent, Larry G.

    2009-01-01

    Although anthropogenic pollutants are thought to threaten reptilian species, there are few toxicity studies on reptiles. We evaluated the toxicity of Pb as lead acetate to the Western fence lizard (Sceloporus occidentalis). The acute lethal dose and sub-acute (14-day) toxicity studies were used to narrow exposure concentrations for a sub-chronic (60-day) study. In the sub-chronic study, adult and juvenile male lizards were dosed via gavage with 0, 1, 10 and 20 mg Pb/kg-bw/day. Mortality was limited and occurred only at the highest dose (20 mg Pb/kg-bw/d). There were statistically significant sub-lethal effects of 10 and 20 mg Pb/kg-bw/d on body weight, cricket consumption, organ weight, hematological parameters and post-dose behaviors. Of these, Pb-induced changes in body weight are most useful for ecological risk assessment because it is linked to fitness in wild lizard populations. The Western fence lizard is a useful model for reptilian toxicity studies. - The Western fence lizard, Sceloporus occidentalis, is sensitive to Pb and is a useful laboratory model for ecotoxicological testing of reptiles.

  3. Growth and activity of Sceloporus cowlesi (southwestern fence lizard)

    Science.gov (United States)

    Heather L. Bateman; Alice Chung-MacCoubrey

    2012-01-01

    Lizards from the Sceloporus undulatus complex have been the subject of many studies on lizard ecology (Hager 2001; Rosenblum 2006; Rosenblum et al. 2007), behavior (Hein and Whitaker 1997; Robertson and Rosenblum 2009), and reproduction (Vinegar 1975; Robertson and Rosenblum 2010). However, genetic data (Leache and Reeder 2002) support reallocation of the subspecies of...

  4. Leukocyte profiles for western fence lizards, Sceloporus occidentalis, naturally infected by the malaria parasite Plasmodium mexicanum.

    Science.gov (United States)

    Motz, Victoria L; Lewis, William D; Vardo-Zalik, Anne M

    2014-10-01

    Plasmodium mexicanum is a malaria parasite that naturally infects the western fence lizard, Sceloporus occidentalis , in northern California. We set out to determine whether lizards naturally infected with this malaria parasite have different leukocyte profiles, indicating an immune response to infection. We used 29 naturally infected western fence lizards paired with uninfected lizards based on sex, snout-to-vent length, tail status, and the presence-absence of ectoparasites such as ticks and mites, as well as the presence-absence of another hemoparasite, Schellackia occidentalis. Complete white blood cell (WBC) counts were conducted on blood smears stained with Giemsa, and the proportion of granulocytes per microliter of blood was estimated using the Avian Leukopet method. The abundance of each WBC class (lymphocytes, monocytes, heterophils, eosinophils, and basophils) in infected and uninfected lizards was compared to determine whether leukocyte densities varied with infection status. We found that the numbers of WBCs and lymphocytes per microliter of blood significantly differed (P lizard's immune response to increase the levels of circulating WBCs, but what effect this has on the biology of the parasite remains unclear.

  5. Direct and indirect effects of petroleum production activities on the western fence lizard (Sceloporus occidentalis) as a surrogate for the dunes sagebrush lizard (Sceloporus arenicolus).

    Science.gov (United States)

    Weir, Scott M; Knox, Ami; Talent, Larry G; Anderson, Todd A; Salice, Christopher J

    2016-05-01

    The dunes sagebrush lizard (Sceloporus arenicolus) is a habitat specialist of conservation concern limited to shin oak sand dune systems of New Mexico and Texas (USA). Because much of the dunes sagebrush lizard's habitat occurs in areas of high oil and gas production, there may be direct and indirect effects of these activities. The congeneric Western fence lizard (Sceloporus occidentalis) was used as a surrogate species to determine direct effects of 2 contaminants associated with oil and gas drilling activities in the Permian Basin (NM and TX, USA): herbicide formulations (Krovar and Quest) and hydrogen sulfide gas (H2S). Lizards were exposed to 2 concentrations of H2 S (30 ppm or 90 ppm) and herbicide formulations (1× or 2× label application rate) representing high-end exposure scenarios. Sublethal behavioral endpoints were evaluated, including sprint speed and time to prey detection and capture. Neither H2S nor herbicide formulations caused significant behavioral effects compared to controls. To understand potential indirect effects of oil and gas drilling on the prey base, terrestrial invertebrate biomass and order diversity were quantified at impacted sites to compare with nonimpacted sites. A significant decrease in biomass was found at impacted sites, but no significant effects on diversity. The results suggest little risk from direct toxic effects, but the potential for indirect effects should be further explored. © 2015 SETAC.

  6. Immune responses of eastern fence lizards (Sceloporus undulatus) to repeated acute elevation of corticosterone.

    Science.gov (United States)

    McCormick, Gail L; Langkilde, Tracy

    2014-08-01

    Prolonged elevations of glucocorticoids due to long-duration (chronic) stress can suppress immune function. It is unclear, however, how natural stressors that result in repeated short-duration (acute) stress, such as frequent agonistic social encounters or predator attacks, fit into our current understanding of the immune consequences of stress. Since these types of stressors may activate the immune system due to increased risk of injury, immune suppression may be reduced at sites where individuals are repeatedly exposed to potentially damaging stressors. We tested whether repeated acute elevation of corticosterone (CORT, a glucocorticoid) suppresses immune function in eastern fence lizards (Sceloporus undulatus), and whether this effect varies between lizards from high-stress (high baseline CORT, invaded by predatory fire ants) and low-stress (low baseline CORT, uninvaded) sites. Lizards treated daily with exogenous CORT showed higher hemagglutination of novel proteins by their plasma (a test of constitutive humoral immunity) than control lizards, a pattern that was consistent across sites. There was no significant effect of CORT treatment on bacterial killing ability of plasma. These results suggest that repeated elevations of CORT, which are common in nature, produce immune effects more typical of those expected at the acute end of the acute-chronic spectrum and provide no evidence of modulated consequences of elevated CORT in animals from high-stress sites. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Refractoriness of the western fence lizard (Sceloporus occidentalis) to the Lyme disease group spirochete Borrelia bissettii.

    Science.gov (United States)

    Lane, R S; Mun, J; Eisen, L; Eisen, R J

    2006-08-01

    The western fence lizard, Sceloporus occidentalis, is refractory to experimental infection with Borrelia burgdorferi sensu stricto, one of several Lyme disease spirochetes pathogenic for humans. Another member of the Lyme disease spirochete complex, Borrelia bissettii, is distributed widely throughout North America and a similar, if not identical, spirochete has been implicated as a human pathogen in southern Europe. To determine the susceptibility of S. occidentalis to B. bissettii, 6 naïve lizards were exposed to the feeding activities of Ixodes pacificus nymphs experimentally infected with this spirochete. None of the lizards developed spirochetemias detectable by polymerase chain reaction for up to 8 wk post-tick feeding, infected nymphs apparently lost their B. bissettii infections within 1-2 wk after engorgement, and xenodiagnostic L. pacificus larvae that co-fed alongside infected nymphs did not acquire and maintain spirochetes. In contrast, 3 of 4 naïve deer mice (Peromyscus maniculatus) exposed similarly to feeding by 1 or more B. bissettii-infected nymphs developed patent infections within 4 wk. These and previous findings suggest that the complement system of S. occidentalis typically destroys B. burgdorferi sensu lato spirochetes present in tissues of attached and feeding I. pacificus nymphs, thereby potentially reducing the probability of transmission of these bacteria to humans or other animals by the resultant adult ticks.

  8. Toxic effects of oral 2-amino-4,6-dinitrotoluene in the Western fence lizard (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Craig A., E-mail: craig.a.mcfarland@us.army.mi [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States); Quinn, Michael J [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States); Boyce, John [Biotechnics, LLC, Hillsborough, NC 27278 (United States); LaFiandra, Emily M; Bazar, Matthew A [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States); Talent, Larry G [Oklahoma State University, Department of Natural Resource Ecology and Management, Stillwater, OK 74078 (United States); Johnson, Mark S [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States)

    2011-02-15

    The compound 2-amino-4,6-dinitrotoluene (2A-DNT) was evaluated under laboratory conditions in the Western fence lizard (Sceloporus occidentalis) to assess the potential for reptile toxicity. Oral LD{sub 50} values were 1406 and 1867 mg/kg for male and female lizards, respectively. Based on responses from a 14-day subacute study, a 60-day subchronic experiment followed where lizards were orally dosed at 0, 5, 15, 20, 25, 30 mg/kg-d. At day 60, number of days and survivors, food consumption, and change in body weight were inversely related to dose. Signs of toxicity were characterized by anorexia and generalized cachexia. Significant adverse histopathology was observed in hepatic tissue at {>=}15 mg/kg-d, consistent with hepatocellular transdifferentiation. Based on survival, loss of body weight, diminished food intake, changes in liver, kidney, and testes, and increased blood urea nitrogen, these data suggest a LOAEL of 15 mg/kg-d and a NOAEL of 5 mg/kg-d in S. occidentalis. - Research highlights: Oral LD{sub 50} (mg/kg) values were 1406 for male and 1867 for female lizards. Dose-dependent hepatocellular transdifferentiation was observed at {>=}5 mg/kg-d. Chromaturia in 2A-DNT and the parent TNT suggest biomarkers of exposure and effect. Health effects of metabolites support comprehensive ecological risk assessments. - The Western fence lizard (Sceloporus occidentalis) is a suitable reptile model for assessing the toxicity of energetic compounds and their metabolites.

  9. Toxic effects of oral 2-amino-4,6-dinitrotoluene in the Western fence lizard (Sceloporus occidentalis)

    International Nuclear Information System (INIS)

    McFarland, Craig A.; Quinn, Michael J.; Boyce, John; LaFiandra, Emily M.; Bazar, Matthew A.; Talent, Larry G.; Johnson, Mark S.

    2011-01-01

    The compound 2-amino-4,6-dinitrotoluene (2A-DNT) was evaluated under laboratory conditions in the Western fence lizard (Sceloporus occidentalis) to assess the potential for reptile toxicity. Oral LD 50 values were 1406 and 1867 mg/kg for male and female lizards, respectively. Based on responses from a 14-day subacute study, a 60-day subchronic experiment followed where lizards were orally dosed at 0, 5, 15, 20, 25, 30 mg/kg-d. At day 60, number of days and survivors, food consumption, and change in body weight were inversely related to dose. Signs of toxicity were characterized by anorexia and generalized cachexia. Significant adverse histopathology was observed in hepatic tissue at ≥15 mg/kg-d, consistent with hepatocellular transdifferentiation. Based on survival, loss of body weight, diminished food intake, changes in liver, kidney, and testes, and increased blood urea nitrogen, these data suggest a LOAEL of 15 mg/kg-d and a NOAEL of 5 mg/kg-d in S. occidentalis. - Research highlights: → Oral LD 50 (mg/kg) values were 1406 for male and 1867 for female lizards. → Dose-dependent hepatocellular transdifferentiation was observed at ≥5 mg/kg-d. → Chromaturia in 2A-DNT and the parent TNT suggest biomarkers of exposure and effect. → Health effects of metabolites support comprehensive ecological risk assessments. - The Western fence lizard (Sceloporus occidentalis) is a suitable reptile model for assessing the toxicity of energetic compounds and their metabolites.

  10. Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    Holem, Ryan R. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); ENTRIX, Inc., Okemos, MI 48864 (United States); Hopkins, William A. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)], E-mail: hopkinsw@vt.edu; Talent, Larry G. [Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078 (United States)

    2008-03-15

    Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected.

  11. Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

    International Nuclear Information System (INIS)

    Holem, Ryan R.; Hopkins, William A.; Talent, Larry G.

    2008-01-01

    Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected

  12. Impaired terrestrial and arboreal locomotor performance in the western fence lizard (Sceloporus occidentalis) after exposure to an AChE-inhibiting pesticide

    International Nuclear Information System (INIS)

    DuRant, Sarah E.; Hopkins, William A.; Talent, Larry G.

    2007-01-01

    We examined the effects of a commonly used AChE-inhibiting pesticide on terrestrial and arboreal sprint performance, important traits for predator avoidance and prey capture, in the western fence lizard (Sceloporus occidentalis). Lizards were exposed to carbaryl (2.5, 25, and 250 μg/g) and were raced before and 4, 24, and 96 h after dosing. In the terrestrial setting, exposure to low concentrations of carbaryl had stimulatory effects on performance, but exposure to the highest concentration was inhibitory. No stimulatory effects of carbaryl were noted in the arboreal environment and performance in lizards was reduced after exposure to both the medium and highest dose of carbaryl. Our findings suggest that acute exposure to high concentrations of carbaryl can have important sublethal consequences on fitness-related traits in reptiles and that arboreal locomotor performance is a more sensitive indicator of AChE-inhibiting pesticide poisoning than terrestrial locomotor performance. - Exposure to an acetylcholinesterase-inhibiting pesticide alters locomotor performance in western fence lizards

  13. Impaired terrestrial and arboreal locomotor performance in the western fence lizard (Sceloporus occidentalis) after exposure to an AChE-inhibiting pesticide

    Energy Technology Data Exchange (ETDEWEB)

    DuRant, Sarah E. [Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, 444 Latham Hall, Blacksburg, VA 24061 (United States); University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802 (United States); Hopkins, William A. [Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, 444 Latham Hall, Blacksburg, VA 24061 (United States) and University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802 (United States)]. E-mail: hopkinsw@vt.edu; Talent, Larry G. [Department of Zoology, Oklahoma State University, Stillwater, OK 74078 (United States)

    2007-09-15

    We examined the effects of a commonly used AChE-inhibiting pesticide on terrestrial and arboreal sprint performance, important traits for predator avoidance and prey capture, in the western fence lizard (Sceloporus occidentalis). Lizards were exposed to carbaryl (2.5, 25, and 250 {mu}g/g) and were raced before and 4, 24, and 96 h after dosing. In the terrestrial setting, exposure to low concentrations of carbaryl had stimulatory effects on performance, but exposure to the highest concentration was inhibitory. No stimulatory effects of carbaryl were noted in the arboreal environment and performance in lizards was reduced after exposure to both the medium and highest dose of carbaryl. Our findings suggest that acute exposure to high concentrations of carbaryl can have important sublethal consequences on fitness-related traits in reptiles and that arboreal locomotor performance is a more sensitive indicator of AChE-inhibiting pesticide poisoning than terrestrial locomotor performance. - Exposure to an acetylcholinesterase-inhibiting pesticide alters locomotor performance in western fence lizards.

  14. Unraveling the Relative Importance of Oral and Dermal Contaminant Exposure in Reptiles: Insights from Studies Using the Western Fence Lizard (Sceloporus occidentalis)

    Science.gov (United States)

    Weir, Scott M.; Talent, Larry G.; Anderson, Todd A.; Salice, Christopher J.

    2014-01-01

    Despite widespread recognition of significant data deficiencies, reptiles remain a relatively understudied taxon in ecotoxicology. To conduct ecological risk assessments on reptiles frequently requires using surrogate taxa such as birds, but recent research suggests that reptiles have significantly different exposure profiles and toxicant sensitivity. We exposed western fence lizards, Sceloporus occidentalis, to the same quantities of three model chemicals via oral (gavage) and dermal (ventral skin application) exposure for either 24 or 48 hours. Three phthalate esters (di-methyl phthalate [DMP], di-iso-butyl phthalate [DIBP], and di-n-octyl phthalate [DNOP]) were chosen as model chemicals because they represent a gradient of lipophilicity but are otherwise structurally similar. Overall, the more lipophilic phthalates (DIBP and DNOP) were found to have higher concentrations in tissues than the less lipophilic DMP. Significant differences in tissue concentrations between DIBP and DNOP were tissue-dependent, suggesting that delivery to a site of action following exposure is not only a simple function of lipophilicity. In dermal treatments, DMP usually had fewer detections (except in ventral skin samples), suggesting that lipophilicity (log Kow>2) is a requirement for uptake across the skin. In general, tissue residues were greater in oral treatments than dermal treatments (significant in adipose and liver tissue), but differences were driven strongly by differences in DMP which did not appear to be absorbed well across skin. When differences in tissue residue concentrations between oral and dermal exposure did occur, the difference was not drastic. Taken together these results suggest that dermal exposure should be considered in risk assessments for reptilian receptors. Dermal exposure may be an especially important route for reptiles as their ectothermic physiology translates to lower energetic demands and dietary exposure compared to birds and mammals. PMID

  15. Unraveling the relative importance of oral and dermal contaminant exposure in reptiles: insights from studies using the western fence lizard (Sceloporus occidentalis).

    Science.gov (United States)

    Weir, Scott M; Talent, Larry G; Anderson, Todd A; Salice, Christopher J

    2014-01-01

    Despite widespread recognition of significant data deficiencies, reptiles remain a relatively understudied taxon in ecotoxicology. To conduct ecological risk assessments on reptiles frequently requires using surrogate taxa such as birds, but recent research suggests that reptiles have significantly different exposure profiles and toxicant sensitivity. We exposed western fence lizards, Sceloporus occidentalis, to the same quantities of three model chemicals via oral (gavage) and dermal (ventral skin application) exposure for either 24 or 48 hours. Three phthalate esters (di-methyl phthalate [DMP], di-iso-butyl phthalate [DIBP], and di-n-octyl phthalate [DNOP]) were chosen as model chemicals because they represent a gradient of lipophilicity but are otherwise structurally similar. Overall, the more lipophilic phthalates (DIBP and DNOP) were found to have higher concentrations in tissues than the less lipophilic DMP. Significant differences in tissue concentrations between DIBP and DNOP were tissue-dependent, suggesting that delivery to a site of action following exposure is not only a simple function of lipophilicity. In dermal treatments, DMP usually had fewer detections (except in ventral skin samples), suggesting that lipophilicity (log Kow>2) is a requirement for uptake across the skin. In general, tissue residues were greater in oral treatments than dermal treatments (significant in adipose and liver tissue), but differences were driven strongly by differences in DMP which did not appear to be absorbed well across skin. When differences in tissue residue concentrations between oral and dermal exposure did occur, the difference was not drastic. Taken together these results suggest that dermal exposure should be considered in risk assessments for reptilian receptors. Dermal exposure may be an especially important route for reptiles as their ectothermic physiology translates to lower energetic demands and dietary exposure compared to birds and mammals.

  16. Effect of Temperature on Feeding Period of Larval Blacklegged Ticks (Acari: Ixodidae) on Eastern Fence Lizards.

    Science.gov (United States)

    Rulison, Eric L; Lebrun, Roger A; Ginsberg, Howard S

    2014-11-01

    Ambient temperature can influence tick development time, and can potentially affect tick interactions with pathogens and with vertebrate hosts. We studied the effect of ambient temperature on duration of attachment of larval blacklegged ticks, Ixodes scapularis Say, to eastern fence lizards, Sceloporus undulatus (Bosc & Daudin). Feeding periods of larvae that attached to lizards under preferred temperature conditions for the lizards (WARM treatment: temperatures averaged 36.6°C at the top of the cage and 25.8°C at the bottom, allowing behavioral thermoregulation) were shorter than for larvae on lizards held under cool conditions (COOL treatment temperatures averaged 28.4°C at top of cage and 24.9°C at the bottom). The lizards were infested with larvae four times at roughly monthly intervals. Larval numbers successfully engorging and dropping declined and feeding period was longer after the first infestation. © 2014 Entomological Society of America.

  17. Validation of the HTO-18 method for determination of CO2 production of lizards (genus Sceloporus)

    International Nuclear Information System (INIS)

    Congdon, J.D.; King, W.W.; Nagy, K.A.

    1978-01-01

    The accuracy of doubly-labeled water measurements of CO 2 production in lizards of the genus Sceloporus was assessed by comparison of CO 2 production rates determined simultaneously by labeled water and gas chromatography. Five lizards were weighed and given intraperitoneal injections of 55 μl of water containing 10 microcuries of tritium as HTO and 50 atom % oxygen-18 as H 2 18 O. Initial blood samples were taken from the infraorbital sinus ten hours later, and the lizards were placed in sealed metabolism chambers kept at 28 C. After 179 h the lizards were weighed and blood samples taken. Blood samples were microdistilled, assayed for tritium activity and for oxygen-18 content. Isotope measurements were used to calculate rates of CO 2 production. Gas samples were withdrawn from each chamber after 18, 63, 109, and 179 h and measured against 0.5 and 1.0% CO 2 standards with a Beckman GC-55 gas chromatograph fitted with silica gel 42-60 mesh column. These results were used to calculate rates of CO 2 production. Results supported the conclusion that the doubly-labeled water method accurately measured rates of CO 2 production in Sceloporus lizards, and could therefore be a valuable technique in field studies of lizard energetics

  18. Minimal role of eastern fence lizards in Borrelia burgdorferi transmission in central New Jersey oak/pine woodlands

    Science.gov (United States)

    Rulison, Eric L.; Kerr, Kaetlyn T; Dyer, Megan C; Han, Seungeun; Burke, Russell L.; Tsao, Jean I.; Ginsberg, Howard S.

    2014-01-01

    The Eastern fence lizard, Sceloporus undulatus, is widely distributed in eastern and central North America, ranging through areas with high levels of Lyme disease, as well as areas where Lyme disease is rare or absent. We studied the potential role of S. undulatus in transmission dynamics of Lyme spirochetes by sampling ticks from a variety of natural hosts at field sites in central New Jersey, and by testing the reservoir competence of S. undulatus for Borrelia burgdorferi in the laboratory. The infestation rate of ticks on fence lizards was extremely low (proportion infested = 0.087, n = 23) compared to that on white footed mice and other small mammals (proportion infested = 0.53, n = 140). Of 159 nymphs that had fed as larvae on lizards that had previously been exposed to infected nymphs, none was infected with B. burgdorferi, compared with 79.9% of 209 nymphs that had fed as larvae on infected control mice. Simulations suggest that changes in the numbers of fence lizards in a natural habitat would have little effect on the infection rate of nymphal ticks with Lyme spirochetes. We conclude that in central New Jersey S. undulatus plays a minimal role in the enzootic transmission cycle of Lyme spirochetes.

  19. Pollution biomarkers in the spiny lizard (Sceloporus spp.) from two suburban populations of Monterrey, Mexico.

    Science.gov (United States)

    Aguilera, Carlos; del Pliego, Pamela González; Alfaro, Roberto Mendoza; Lazcano, David; Cruz, Julio

    2012-11-01

    Environmental pollution may severely impact reptile species in urbanized areas. The magnitude of the impact is analyzed in the present study using lizard tail tips for the quantitative evaluation of enzymatic biomarkers of pollution. Spiny lizards (Sceloporus serrifer and S. torquatus) were collected from two suburban localities in the Monterrey metropolitan area, Mexico: Chipinque Ecological Park, a natural protected area, and El Carmen Industrial Park (IP), a highly polluted site. Different enzymes were used as biomarkers including: acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carboxylesterase (CaE), alkaline phosphatase (ALP), acid phosphatase (ACP), superoxide dismutase (SOD) and glutathione S-transferase (GST). The levels of AChE, BChE and ACP activity were not significantly different between localities. AChE and BChE, commonly used as biomarkers of neurotoxic polluting agents (e.g. organophosphate pesticides) do not appear to be affecting the populations from the study locations. In contrast, the levels of CaE, GST, ALP and SOD were significantly different between the localities. These biomarkers are regularly associated with oxidative stress and processes of detoxification, and generally indicate pollution caused by heavy metals or hydrocarbons, which are common in industrial sites. The data resulting from the analysis of these biomarkers indicate that these polluting agents are affecting the populations of Sceloporus in IP. The present work validates the possibility of conducting additional ecotoxicological studies using biomarkers in combination with a nondestructive sampling technique in species of spiny lizards that are abundant in many North America areas.

  20. Parallel behavioral and morphological divergence in fence lizards on two college campuses

    Science.gov (United States)

    Howe, Stephen; Hynes, Stephanie; Hobbs, Brooke; Handal, Karina

    2018-01-01

    The spread of urban development has dramatically altered natural habitats, modifying community relationships, abiotic factors, and structural features. Animal populations living in these areas must perish, emigrate, or find ways to adjust to a suite of new selective pressures. Those that successfully inhabit the urban environment may make behavioral, physiological, and/or morphological adjustments that represent either evolutionary change and/or phenotypic plasticity. We tested for effects of urbanization on antipredator behavior and associated morphology across an urban-wild gradient in the western fence lizard (Sceloporus occidentalis) in two California counties, Santa Barbara and San Luis Obispo. We compared college campuses in both counties with adjacent rural habitats, conducting field trials that allowed us to characterize antipredator behavior in response to the acute stress of capture. We found notable divergence between campus and rural behavior, with campus lizards more frequently exhibiting diminished escape behavior, including tonic immobility, and lower sprint speeds. Furthermore, campus females had significantly shorter limbs, and while this did not explain variation in sprint speed, those with shorter limbs were more likely to show tonic immobility. We hypothesize that these parallel behavioral and morphological changes on both campuses reflect adjustment to a novel environment involving changes in predation and human presence. PMID:29444102

  1. Phylogenomics of a rapid radiation: is chromosomal evolution linked to increased diversification in north american spiny lizards (Genus Sceloporus)?

    Science.gov (United States)

    Leaché, Adam D; Banbury, Barbara L; Linkem, Charles W; de Oca, Adrián Nieto-Montes

    2016-03-22

    Resolving the short phylogenetic branches that result from rapid evolutionary diversification often requires large numbers of loci. We collected targeted sequence capture data from 585 nuclear loci (541 ultraconserved elements and 44 protein-coding genes) to estimate the phylogenetic relationships among iguanian lizards in the North American genus Sceloporus. We tested for diversification rate shifts to determine if rapid radiation in the genus is correlated with chromosomal evolution. The phylogenomic trees that we obtained for Sceloporus using concatenation and coalescent-based species tree inference provide strong support for the monophyly and interrelationships among nearly all major groups. The diversification analysis supported one rate shift on the Sceloporus phylogeny approximately 20-25 million years ago that is associated with the doubling of the speciation rate from 0.06 species/million years (Ma) to 0.15 species/Ma. The posterior probability for this rate shift occurring on the branch leading to the Sceloporus species groups exhibiting increased chromosomal diversity is high (posterior probability = 0.997). Despite high levels of gene tree discordance, we were able to estimate a phylogenomic tree for Sceloporus that solves some of the taxonomic problems caused by previous analyses of fewer loci. The taxonomic changes that we propose using this new phylogenomic tree help clarify the number and composition of the major species groups in the genus. Our study provides new evidence for a putative link between chromosomal evolution and the rapid divergence and radiation of Sceloporus across North America.

  2. Ontogenic development of spermatids during spermiogenesis in the high altitude bunchgrass lizard (Sceloporus bicanthalis).

    Science.gov (United States)

    Rheubert, Justin; Touzinsky, Katherine; Hernández-Gallegos, Oswaldo; Granados-González, Gisela; Gribbins, Kevin

    2012-04-01

    The body of ultrastructural data on spermatid characters during spermiogenesis continues to grow in reptiles, but is still relatively limited within the squamates. This study focuses on the ontogenic events of spermiogenesis within a viviparous and continually spermatogenic lizard, from high altitude in Mexico. Between the months of June and August, testicular tissues were collected from eight spermatogenically active bunchgrass lizards (Sceloporus bicanthalis) from Nevado de Toluca, México. The testicular tissues were processed for transmission electron microscopy and analyzed to access the ultrastructural differences between spermatid generations during spermiogenesis. Interestingly, few differences exist between S. bicanthalis spermiogenesis when compared with what has been described for other saurian squamates. Degrading and coiling membrane structures similar to myelin figures were visible within the developing acrosome that are likely remnants from Golgi body vesicles. During spermiogenesis, an electron lucent area between the subacrosomal space and the acrosomal medulla was observed, which has been observed in other squamates but not accurately described. Thus, we elect to term this region the acrosomal lucent ridge. This study furthers the existing knowledge of spermatid development in squamates, which could be useful in future work on the reproductive systems in high altitude viviparous lizard species.

  3. Purification and characterization of liver lectins from a lizard, Sceloporus spinosus.

    Science.gov (United States)

    Fenton, N Bertha; Arreguín, L Barbarin; Méndez, C Fausto; Arreguín, E Roberto

    2004-05-01

    This study discusses the purification of soluble beta-galactose lectins obtained from the lizard liver of Sceloporus spinosus. The first lectin named lizard hepatic lectin-1 (LHL-1) presented a molecular weight of 31,750, with an isoelectric point of 4.25. The highest specific hemagglutinating activity was achieved using human blood type A1: N-acetylgalactosamine (GalNAc)-galactose (Gal)-fucose (Fuc). Carbohydrate inhibition assays indicated a higher lectin specificity for GalNAc. For LHL-2 the molecular weight obtained was 23,850 with an isoelectric point of 3.25. The highest carbohydrate specificity was observed for Gal. These lizard hepatic lectins are similar to the mammal hepatic lectins previously reported. However, it is different from the alligator hepatic lectin (AHL). The homology analyses of LHL-1 resulted in 100% identity with the Steroidogenic acute regulatory protein (StAR), while LHL-2 was similar to adenylate kinase (75% identity). We suggest that these liver lectins are related to the inherent functions of liver previously reported.

  4. Nutritional modulation of IGF-1 in relation to growth and body condition in Sceloporus lizards.

    Science.gov (United States)

    Duncan, Christine A; Jetzt, Amanda E; Cohick, Wendie S; John-Alder, Henry B

    2015-05-15

    Nutrition and energy balance are important regulators of growth and the growth hormone/insulin-like growth factor (GH/IGF) axis. However, our understanding of these functions does not extend uniformly to all classes of vertebrates and is mainly limited to controlled laboratory conditions. Lizards can be useful models to improve our understanding of the nutritional regulation of the GH/IGF-1 axis because many species are relatively easy to observe and manipulate both in the laboratory and in the field. In the present study, the effects of variation in food intake on growth, body condition, and hepatic IGF-1 mRNA levels were measured in (1) juveniles of Sceloporus jarrovii maintained on a full or 1/3 ration and (2) hatchlings of Sceloporus undulatus subjected to full or zero ration with or without re-feeding. These parameters plus plasma IGF-1 were measured in a third experiment using adults of S. undulatus subjected to full or zero ration with or without re-feeding. In all experiments, plasma corticosterone was measured as an anticipated indicator of nutritional stress. In S. jarrovii, growth and body condition were reduced but lizards remained in positive energy balance on 1/3 ration, and hepatic IGF-1 mRNA and plasma corticosterone were not affected in comparison to full ration. In S. undulatus, growth, body condition, hepatic IGF-1 mRNA, and plasma IGF-1 were all reduced by zero ration and restored by refeeding. Plasma corticosterone was increased in response to zero ration and restored by full ration in hatchlings but not adults of S. undulatus. These data indicate that lizards conform to the broader vertebrate model in which severe food deprivation and negative energy balance is required to attenuate systemic IGF-1 expression. However, when animals remain in positive energy balance, reduced food intake does not appear to affect systemic IGF-1. Consistent with other studies on lizards, the corticosterone response to reduced food intake is an unreliable indicator

  5. Evolutionary Interactions Between Visual and Chemical Signals: Chemosignals Compensate for the Loss of a Visual Signal in Male Sceloporus Lizards.

    Science.gov (United States)

    Pruett, Jake A; Zúñiga-Vega, J Jaime; Campos, Stephanie M; Soini, Helena A; Novotny, Milos V; Vital-García, Cuauhcihuatl; Martins, Emília P; Hews, Diana K

    2016-11-01

    Animals rely on multimodal signals to obtain information from conspecifics through alternative sensory systems, and the evolutionary loss of a signal in one modality may lead to compensation through increased use of signals in an alternative modality. We investigated associations between chemical signaling and evolutionary loss of abdominal color patches in males of four species (two plain-bellied and two colorful-bellied) of Sceloporus lizards. We conducted field trials to compare behavioral responses of male lizards to swabs with femoral gland (FG) secretions from conspecific males and control swabs (clean paper). We also analyzed the volatile organic compound (VOC) composition of male FG secretions by stir bar extraction and gas chromatography-mass spectrometry (GC-MS) to test the hypothesis that loss of the visual signal is associated with elaboration of the chemical signal. Males of plain-bellied, but not colorful-bellied species exhibited different rates of visual displays when exposed to swabs of conspecific FG secretions relative to control swabs. The VOC composition of male Sceloporus FG secretions was similar across all four species, and no clear association between relative abundances of VOCs and evolutionary loss of abdominal color patches was observed. The emerging pattern is that behavioral responses to conspecific chemical signals are species- and context-specific in male Sceloporus, and compensatory changes in receivers, but not signalers may be involved in mediating increased responsiveness to chemical signals in males of plain-bellied species.

  6. Temporal germ cell development strategy during continuous spermatogenesis within the montane lizard, Sceloporus bicanthalis (Squamata; Phrynosomatidae).

    Science.gov (United States)

    Gribbins, Kevin; Anzalone, Marla; Collier, Matthew; Granados-González, Gisela; Villagrán-Santa Cruz, Maricela; Hernández-Gallegos, Oswaldo

    2011-10-01

    Sceloporus bicanthalis is a viviparous lizard that lives at higher elevations in Mexico. Adult male S. bicanthalis were collected (n = 36) from the Nevado de Toluca, Mexico (elevation is 4200 m) during August to December, 2007 and January to July, 2008. Testes were extracted, fixed in Trumps, and dehydrated in a graded series of ethanol. Tissues were embedded, sectioned (2 μm), stained, and examined via a light microscope to determine the spermatogenic developmental strategy of S. bicanthalis. In all months examined, the testes were spermiogenically active; based on this, plus the presence of sperm in the lumina of seminiferous tubules, we inferred that S. bicanthalis had year-round or continuous spermatogenesis, unlike most reptiles that occupy a temperate or montane habitat. It was recently reported that seasonally breeding reptiles had a temporal germ cell development strategy similar to amphibians, where germ cells progress through spermatogenesis as a single population, which leads to a single spermiation event. This was much different than spatial development within the testis of other derived amniotes. We hypothesized that germ cell development was temporal in S. bicanthalis. Therefore, we wanted to determine whether reptiles that practice continuous spermatogenesis have a mammalian-like spatial germ cell development, which is different than the typical temperate reptile exhibiting a temporal development. In the present study, S. bicanthalis had a temporal development strategy, despite its continuous spermatogenic cycle, making them similar to tropical anoles. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Ornamentation, age, and survival of female striped plateau lizards, Sceloporus virgatus

    Science.gov (United States)

    Weiss, Stacey L.

    2016-04-01

    Individuals with greater expression of secondary sexual traits are often older and have higher survivorship than individuals with lower expression; if so, assessment of such indicator traits may provide genetic and/or direct benefits to potential mates. I examined the relationship between ornament expression, age, and survival in the striped plateau lizard, Sceloporus virgatus, a species with female-specific ornamentation that honestly signals reproductive quality. I followed a group of females from 2008 to 2013, examined ornament color and size as females aged, and compared ornamentation of survivors versus non-survivors. In addition, I explored whether other (non-ornamental) phenotypic characters predicted survival. I found that peak ornament expression (both color and size) of individual females changed year to year but appeared to be a weak signal of age due to high among-female variation in ornament expression that occurred independent of age and a non-linear pattern of change for ornament color. However, both absolute and relative ornament size did increase significantly as an individual aged and therefore may provide some age-related information such as reproductive investment, which is expected to increase as residual reproductive value declines with age. Individual survival was unrelated to peak ornament expression and to other phenotypic variables measured, providing no support for the ornament as a viability indicator and suggesting that individual survival prospects are affected by stochastic and environmental factors.

  8. Skin lipids of the striped plateau lizard ( Sceloporus virgatus) correlate with female receptivity and reproductive quality alongside visual ornaments

    Science.gov (United States)

    Goldberg, Jay K.; Wallace, Alisa K.; Weiss, Stacey L.

    2017-10-01

    Sex pheromones can perform a variety of functions ranging from revealing the location of suitable mates to being honest signals of mate quality, and they are used in the mate selection process by many species of reptile. In this study, we determined whether the skin lipids of female striped plateau lizards ( Sceloporus virgatus) can predict the reproductive quality of females, thereby having the potential to serve as pheromones. Using gas chromatography/mass spectrometry, we identified 17 compounds present in skin lipids of female lizards. Using principal component analysis to compare the skin lipid profile of receptive and non-receptive females, we determined that an uncharacterized compound may allow for chemical identification of receptive mates. We also compared extracted principal components to measures of female fitness and reproductive qualities and found that the level of two 18 carbon fatty acids present in a female's skin lipids may indicate her clutch size. Finally, we compared the information content of the skin lipids to that of female-specific color ornaments to assess whether chemical and visual cues transmit different information or not. We found that the chroma of a female's orange throat patch is also related to her clutch size, suggesting that chemical signals may reinforce the information communicated by visual ornamentation in this species which would support the "backup signals" hypothesis for multiple signals.

  9. Pteridine, not carotenoid, pigments underlie the female-specific orange ornament of striped plateau lizards (Sceloporus virgatus).

    Science.gov (United States)

    Weiss, S L; Foerster, K; Hudon, J

    2012-02-01

    Indicator models of sexual selection suggest that signal honesty is maintained via costs of ornament expression. Carotenoid-based visual signals are a well-studied example, as carotenoids may be environmentally limited and impact signaler health. However, not all bright yellow, orange and red ornaments found in vertebrates are carotenoid-based; pteridine pigments may also produce these colors. We examine the contribution of carotenoid and pteridine pigments to the orange reproductive color of female striped plateau lizards (Sceloporus virgatus). This color ornament reliably indicates female mate quality, yet costs maintaining signal honesty are currently unknown. Dietary carotenoid manipulations did not affect orange color, and orange skin differed from surrounding white skin in drosopterin, not carotenoid, content. Further, orange color positively correlated with drosopterin, not carotenoid, concentration. Drosopterin-based female ornaments avoid the direct trade-offs of using carotenoids for ornament production vs egg production, thus may relax counter-selection against color ornament exaggeration in females. Direct experimentation is needed to determine the actual costs of pteridine-based ornaments. Like carotenoids, pteridines influence important biological processes, including immune and antioxidant function; predation and social costs may also be relevant. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. The relative influence of road characteristics and habitat on adjacent lizard populations in arid shrublands

    Science.gov (United States)

    Hubbard, Kaylan A.; Chalfoun, Anna D.; Gerow, Kenneth G.

    2016-01-01

    As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.

  11. Multi-locus estimates of population structure and migration in a fence lizard hybrid zone.

    Directory of Open Access Journals (Sweden)

    Adam D Leaché

    Full Text Available A hybrid zone between two species of lizards in the genus Sceloporus (S. cowlesi and S. tristichus on the Mogollon Rim in Arizona provides a unique opportunity to study the processes of lineage divergence and merging. This hybrid zone involves complex interactions between 2 morphologically and ecologically divergent subspecies, 3 chromosomal groups, and 4 mitochondrial DNA (mtDNA clades. The spatial patterns of divergence between morphology, chromosomes and mtDNA are discordant, and determining which of these character types (if any reflects the underlying population-level lineages that are of interest has remained impeded by character conflict. The focus of this study is to estimate the number of populations interacting in the hybrid zone using multi-locus nuclear data, and to then estimate the migration rates and divergence time between the inferred populations. Multi-locus estimates of population structure and gene flow were obtained from 12 anonymous nuclear loci sequenced for 93 specimens of Sceloporus. Population structure estimates support two populations, and this result is robust to changes to the prior probability distribution used in the Bayesian analysis and the use of spatially-explicit or non-spatial models. A coalescent analysis of population divergence suggests that gene flow is high between the two populations, and that the timing of divergence is restricted to the Pleistocene. The hybrid zone is more accurately described as involving two populations belonging to S. tristichus, and the presence of S. cowlesi mtDNA haplotypes in the hybrid zone is an anomaly resulting from mitochondrial introgression.

  12. fences

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2013-05-01

    Full Text Available After the Public Spaces (PB 35, it is the right time to speak about fences. Space and fencing. We, the members of the editorial board, probably suffer from an acute form of agoraphilia – the love for an open space, a wide and open world made us talk about it (82. Our cities suffer from agoraphobia, a fear of open spaces, and its complication – fencephilia.Chekhov’s claustrophobia brought him to Sakhalin and gave widely cited descriptions to many Siberian cities. Irkutsk, unlike Tomsk, for example, was called “a cultured city… Almost Europe!” But not every Irkutsk citizen knows that this quotation is cut short. When using the word ‘cultured’, the writer meant the absence of “nasty fences, absurd advertisements and wastelands where signs prohibit stopping”.However, after 100 some odd years, “the cultural layer has grown, and the cultural level has dropped”.Why? Let’s return to education. Alexander Rappaport opens discussion about a school of the future (30.This issue comprises international and Siberian architectural events (14. And many good and different fences. Good fences are represented in the collection of articles on fences of all times and nations. The hot times of fencing are analyzed in the article by psychologist Konstantin Lidin (72.

  13. Female Preference for Sympatric vs. Allopatric Male Throat Color Morphs in the Mesquite Lizard (Sceloporus grammicus) Species Complex

    OpenAIRE

    Bastiaans, Elizabeth; Bastiaans, Mary Jane; Morinaga, Gen; Castañeda Gaytán, José Gamaliel; Marshall, Jonathon C.; Bane, Brendan; de la Cruz, Fausto Méndez; Sinervo, Barry

    2014-01-01

    Color polymorphic sexual signals are often associated with alternative reproductive behaviors within populations, and the number, frequency, or type of morphs present often vary among populations. When these differences lead to assortative mating by population, the study of such polymorphic taxa may shed light on speciation mechanisms. We studied two populations of a lizard with polymorphic throat color, an important sexual signal. Males in one population exhibit orange, yellow, or blue throa...

  14. Female preference for sympatric vs. allopatric male throat color morphs in the mesquite lizard (Sceloporus grammicus species complex.

    Directory of Open Access Journals (Sweden)

    Elizabeth Bastiaans

    Full Text Available Color polymorphic sexual signals are often associated with alternative reproductive behaviors within populations, and the number, frequency, or type of morphs present often vary among populations. When these differences lead to assortative mating by population, the study of such polymorphic taxa may shed light on speciation mechanisms. We studied two populations of a lizard with polymorphic throat color, an important sexual signal. Males in one population exhibit orange, yellow, or blue throats; whereas males in the other exhibit orange, yellow, or white throats. We assessed female behavior when choosing between allopatric and sympatric males. We asked whether females discriminated more when the allopatric male was of an unfamiliar morph than when the allopatric male was similar in coloration to the sympatric male. We found that female rejection of allopatric males relative to sympatric males was more pronounced when males in a pair were more different in throat color. Our findings may help illuminate how behavioral responses to color morph differences between populations with polymorphic sexual signals contribute to reproductive isolation.

  15. Female preference for sympatric vs. allopatric male throat color morphs in the mesquite lizard (Sceloporus grammicus) species complex.

    Science.gov (United States)

    Bastiaans, Elizabeth; Bastiaans, Mary Jane; Morinaga, Gen; Castañeda Gaytán, José Gamaliel; Marshall, Jonathon C; Bane, Brendan; de la Cruz, Fausto Méndez; Sinervo, Barry

    2014-01-01

    Color polymorphic sexual signals are often associated with alternative reproductive behaviors within populations, and the number, frequency, or type of morphs present often vary among populations. When these differences lead to assortative mating by population, the study of such polymorphic taxa may shed light on speciation mechanisms. We studied two populations of a lizard with polymorphic throat color, an important sexual signal. Males in one population exhibit orange, yellow, or blue throats; whereas males in the other exhibit orange, yellow, or white throats. We assessed female behavior when choosing between allopatric and sympatric males. We asked whether females discriminated more when the allopatric male was of an unfamiliar morph than when the allopatric male was similar in coloration to the sympatric male. We found that female rejection of allopatric males relative to sympatric males was more pronounced when males in a pair were more different in throat color. Our findings may help illuminate how behavioral responses to color morph differences between populations with polymorphic sexual signals contribute to reproductive isolation.

  16. 76 FR 19304 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Science.gov (United States)

    2011-04-07

    ... for Dunes Sagebrush Lizard AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule... list the dunes sagebrush lizard (Sceloporus arenicolus) under the Endangered Species Act of 1973, as... dunes sagebrush lizard (Sceloporus arenicolus) that was published in the Federal Register on December 14...

  17. Dimorfismo sexual y ciclo reproductivo de la lagartija espinosa arbórea Sceloporus formosus Wiegmann (Squamata: Phrynosomatidae de la zona central del estado de Oaxaca, México Sexual dimorphism and reproductive cycle in the arboreal spiny lizard Sceloporus formosus Wiegmann (Squamata: Phrynosomatidae from central Oaxaca, México

    Directory of Open Access Journals (Sweden)

    AURELIO RAMÍREZ-BAUTISTA

    2009-12-01

    Full Text Available It is well known that geographic variation oceurs in life history characteristics among populations of lizards. Variations in life histories found in some studies are possibly adaptations to environmental pressures. In southwestern México, the reproductive characteristics of the endemic species Sceloporus formosus have been poorly studied throughout its geographic range. We used specimens from scientific collections to describe male and female reproductive eyeles and sexual dimorphism of S. formosus. Other viviparous Sceloporus from high elevations show sexual dimorphism, with males being larger in many morphological characteristics than females. We therefore expected that S. formosus would show sexual dimorphism. However, we found no sexual dimorphism. Males reached sexual maturity at a smaller (47 mm snout-vent length (SVL than females (50 mm. There were no significant differences between sexes and months in liver mass. However, fat body mass in females was greater than in males. For males, there was significant relationship between log10-testis volume and log10-SVL. Testis volume was positively correlated with temperature and was smallest during October, November, and December. For females, there was no significant effect of month on gonad volume. Vitellogenesis oceurred from April to November. Vitellogenic follicles and embryonic development were significantly correlated with precipitation (Pearson correlation, r = 0.80, n = 10, P = 0.0081 and photoperiod (Pearson correlation, r = 0.72, n = 10, P Es bien conocido que la variación geográfica ocurre en las características de historias de vida entre poblaciones de especies de lagartijas. Las variaciones en las características de historias de vida encontradas en algunos estudios son posiblemente adaptaciones a las presiones del ambiente. En el suroeste de México, habita la especie endémica, Sceloporus formosus la cual ha sido poco estudiada en sus características reproductivas a trav

  18. Detection of Borrelia burgdorferi DNA in Lizards from Southern Maryland

    OpenAIRE

    SWANSON, KATHERINE I.; NORRIS, DOUGLAS E.

    2007-01-01

    Lizards serve as hosts for Ixodes ticks in the western and southeastern United States and may affect the transmission cycles of Borrelia burgdorferi in these regions. In Maryland, the role of lizards in the maintenance and transmission cycle of this pathogen has not been examined. We tested 29 lizards (Sceloporus undulatus and Eumeces spp.) and 21 ticks from these lizards for the presence of B. burgdorferi. Eight lizards were positive by polymerase chain reaction (PCR) for at least one B. bur...

  19. Fear no colors? Observer clothing color influences lizard escape behavior.

    Science.gov (United States)

    Putman, Breanna J; Drury, Jonathan P; Blumstein, Daniel T; Pauly, Gregory B

    2017-01-01

    Animals often view humans as predators, leading to alterations in their behavior. Even nuanced aspects of human activity like clothing color affect animal behavior, but we lack an understanding of when and where such effects will occur. The species confidence hypothesis posits that birds are attracted to colors found on their bodies and repelled by non-body colors. Here, we extend this hypothesis taxonomically and conceptually to test whether this pattern is applicable in a non-avian reptile and to suggest that species should respond less fearfully to their sexually-selected signaling color. Responses to clothing color could also be impacted by habituation to humans, so we examine whether behavior varied between areas with low and high human activity. We quantified the effects of four T-shirt colors on flight initiation distances (FID) and on the ease of capture in western fence lizards (Sceloporus occidentalis), and we accounted for detectability against the background environment. We found no differences in lizard behavior between sites. However, lizards tolerated the closest approaches and were most likely to be captured when approached with the T-shirt that resembled their sexually-selected signaling color. Because changes in individual behavior affect fitness, choice of clothing color by people, including tourists, hikers, and researchers, could impact wildlife populations and research outcomes.

  20. Fear no colors? Observer clothing color influences lizard escape behavior

    Science.gov (United States)

    Drury, Jonathan P.; Blumstein, Daniel T.; Pauly, Gregory B.

    2017-01-01

    Animals often view humans as predators, leading to alterations in their behavior. Even nuanced aspects of human activity like clothing color affect animal behavior, but we lack an understanding of when and where such effects will occur. The species confidence hypothesis posits that birds are attracted to colors found on their bodies and repelled by non-body colors. Here, we extend this hypothesis taxonomically and conceptually to test whether this pattern is applicable in a non-avian reptile and to suggest that species should respond less fearfully to their sexually-selected signaling color. Responses to clothing color could also be impacted by habituation to humans, so we examine whether behavior varied between areas with low and high human activity. We quantified the effects of four T-shirt colors on flight initiation distances (FID) and on the ease of capture in western fence lizards (Sceloporus occidentalis), and we accounted for detectability against the background environment. We found no differences in lizard behavior between sites. However, lizards tolerated the closest approaches and were most likely to be captured when approached with the T-shirt that resembled their sexually-selected signaling color. Because changes in individual behavior affect fitness, choice of clothing color by people, including tourists, hikers, and researchers, could impact wildlife populations and research outcomes. PMID:28792983

  1. Fear no colors? Observer clothing color influences lizard escape behavior.

    Directory of Open Access Journals (Sweden)

    Breanna J Putman

    Full Text Available Animals often view humans as predators, leading to alterations in their behavior. Even nuanced aspects of human activity like clothing color affect animal behavior, but we lack an understanding of when and where such effects will occur. The species confidence hypothesis posits that birds are attracted to colors found on their bodies and repelled by non-body colors. Here, we extend this hypothesis taxonomically and conceptually to test whether this pattern is applicable in a non-avian reptile and to suggest that species should respond less fearfully to their sexually-selected signaling color. Responses to clothing color could also be impacted by habituation to humans, so we examine whether behavior varied between areas with low and high human activity. We quantified the effects of four T-shirt colors on flight initiation distances (FID and on the ease of capture in western fence lizards (Sceloporus occidentalis, and we accounted for detectability against the background environment. We found no differences in lizard behavior between sites. However, lizards tolerated the closest approaches and were most likely to be captured when approached with the T-shirt that resembled their sexually-selected signaling color. Because changes in individual behavior affect fitness, choice of clothing color by people, including tourists, hikers, and researchers, could impact wildlife populations and research outcomes.

  2. 76 FR 62087 - Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas

    Science.gov (United States)

    2011-10-06

    ...] Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas AGENCY: Fish... draft Texas Conservation Plan for the Dunes Sagebrush Lizard (TCP). The draft TCP will function as a... the Applicant for the dunes sagebrush lizard (Sceloporus arenicolus) throughout its range in Texas...

  3. Lizard activity and abundance greater in burned habitat of a xeric montane forest

    Science.gov (United States)

    Fouts, Kevin L.; Moore, Clinton; Johnson, Kristine D.; Maerz, John C.

    2017-01-01

    Restoring the natural or historical state of ecosystems is a common objective among resource managers, but determining whether desired system responses to management actions are occurring is often protracted and challenging. For wildlife, the integration of mechanistic habitat modeling with population monitoring may provide expedited measures of management effectiveness and improve understanding of how management actions succeed or fail to recover populations. Southern Appalachia is a region of high biodiversity that has undergone dramatic change as a result of human activities such as historic logging, exotic invasions, and alteration of disturbance regimes—including reduction in application of fire. Contemporary efforts to restore fire-maintained ecosystems within southern Appalachian forests require tools to assess the effects of fire management practices on individual animal fitness and relate them to corresponding influences on species abundance. Using automated sensing equipment, we investigated the effects of burned forests on reptile habitat suitability within the western portion of Great Smoky Mountains National Park, Tennessee. Specifically, we used microclimate measurements to model northern fence lizard Sceloporus undulatus hyacinthinus diurnal activity budgets in unburned and variable burn age (3–27-y) forest stands. We estimated northern fence lizard occurrence and abundance along transects through burned and unburned forests. Burned forest stands had microclimates that resulted in longer modeled daily activity periods under most conditions during summer. S. undulatus abundance was 4.75 times greater on burned stands compared to paired unburned stands, although the relationship between burn age and abundance was not well determined. Results suggest the more open habitat structure of burned areas within these xeric pine–oak forests may benefit S. undulatus.

  4. Japanese fences

    Directory of Open Access Journals (Sweden)

    Dimitri Malko

    2013-05-01

    Full Text Available In Japan, there is an inclination towards obscuring the demarcation between the private and the public space. The high palisades surrounding “skya” style constructions enclose the gardens where the low fences line the vegetation.In the religious domain, the palisades that separate the sacred space from the secular space, called “tama-gaki”, are found neighbouring “koran” style fences.Stone can sometimes be used as part or only component of the barrier.The barriers and palisades in Japan are utilized to hide the buildings and gardens from the public space, but they stay entirely as art works in which the carpenters of the archipelago put sense of aesthetic and tradition, preserving the privacy, harmony of the landscape and calm.

  5. Lizard community structure across a grassland - creosote bush ecotone in the Chihuahuan Desert

    OpenAIRE

    Menke, Sean B

    2003-01-01

    I investigated the distribution and abundance of lizard species (Aspidoscelis inornatus, Aspidoscelis tesselatus, Aspidoscelis tigris, Aspidoscelis uniparens, Cophosaurus texanus, Crotaphytus collaris, Eumeces obsoletus, Gambelia wislizenii, Holbrookia maculata, Phrynosoma cornutum, Sceloporus magister, and Uta stansburiana) across a desert grassland - creosote bush (Larrea tridentata) ecotone in Dona Ana County, New Mexico. The ecotonal area in the Jomada del Muerto basin has increased drama...

  6. Permeability of roads to movement of scrubland lizards and small mammals

    Science.gov (United States)

    Brehme, Cheryl S.; Tracey, Jeff A.; McClenaghan, Leroy R.; Fisher, Robert N.

    2013-01-01

    A primary objective of road ecology is to understand and predict how roads affect connectivity of wildlife populations. Road avoidance behavior can fragment populations, whereas lack of road avoidance can result in high mortality due to wildlife-vehicle collisions. Many small animal species focus their activities to particular microhabitats within their larger habitat. We sought to assess how different types of roads affect the movement of small vertebrates and to explore whether responses to roads may be predictable on the basis of animal life history or microhabitat preferences preferences. We tracked the movements of fluorescently marked animals at 24 sites distributed among 3 road types: low-use dirt, low-use secondary paved, and rural 2-lane highway. Most data we collected were on the San Diego pocket mouse (Chaetodipus fallax), cactus mouse (Peromyscus eremicus), western fence lizard (Sceloporus occidentalis), orange-throated whiptail (Aspidoscelis hyperythra), Dulzura kangaroo rat (Dipodomys simulans) (dirt, secondary paved), and deer mouse (Peromyscus maniculatus) (highway only). San Diego pocket mice and cactus mice moved onto dirt roads but not onto a low-use paved road of similar width or onto the highway, indicating they avoidpaved road substrate. Both lizard species moved onto the dirt and secondary paved roads but avoided the rural 2-lane rural highway, indicating they may avoid noise, vibration, or visual disturbance from a steady flow of traffic. Kangaroo rats did not avoid the dirt or secondary paved roads. Overall, dirt and secondary roads were more permeable to species that prefer to forage or bask in open areas of their habitat, rather than under the cover of rocks or shrubs. However, all study species avoided the rural 2-lane highway. Our results suggest that microhabitat use preferences and road substrate help predict species responses to low-use roads,but roads with heavy traffic may deter movement of a much wider range of small animal

  7. Permeability of roads to movement of scrubland lizards and small mammals.

    Science.gov (United States)

    Brehme, Cheryl S; Tracey, Jeff A; McClenaghan, Leroy R; Fisher, Robert N

    2013-08-01

    A primary objective of road ecology is to understand and predict how roads affect connectivity of wildlife populations. Road avoidance behavior can fragment populations, whereas lack of road avoidance can result in high mortality due to wildlife-vehicle collisions. Many small animal species focus their activities to particular microhabitats within their larger habitat. We sought to assess how different types of roads affect the movement of small vertebrates and to explore whether responses to roads may be predictable on the basis of animal life history or microhabitat preferences preferences. We tracked the movements of fluorescently marked animals at 24 sites distributed among 3 road types: low-use dirt, low-use secondary paved, and rural 2-lane highway. Most data we collected were on the San Diego pocket mouse (Chaetodipus fallax), cactus mouse (Peromyscus eremicus), western fence lizard (Sceloporus occidentalis), orange-throated whiptail (Aspidoscelis hyperythra), Dulzura kangaroo rat (Dipodomys simulans) (dirt, secondary paved), and deer mouse (Peromyscus maniculatus) (highway only). San Diego pocket mice and cactus mice moved onto dirt roads but not onto a low-use paved road of similar width or onto the highway, indicating they avoid paved road substrate. Both lizard species moved onto the dirt and secondary paved roads but avoided the rural 2-lane rural highway, indicating they may avoid noise, vibration, or visual disturbance from a steady flow of traffic. Kangaroo rats did not avoid the dirt or secondary paved roads. Overall, dirt and secondary roads were more permeable to species that prefer to forage or bask in open areas of their habitat, rather than under the cover of rocks or shrubs. However, all study species avoided the rural 2-lane highway. Our results suggest that microhabitat use preferences and road substrate help predict species responses to low-use roads, but roads with heavy traffic may deter movement of a much wider range of small animal

  8. Food supplementation and testosterone interact to influence reproductive behavior and immune function in Sceloporus graciosus.

    Science.gov (United States)

    Ruiz, Mayté; French, Susannah S; Demas, Gregory E; Martins, Emília P

    2010-02-01

    The energetic resources in an organism's environment are essential for executing a wide range of life-history functions, including immunity and reproduction. Most energetic budgets, however, are limited, which can lead to trade-offs among competing functions. Increasing reproductive effort tends to decrease immunity in many cases, and increasing total energy via supplemental feedings can eliminate this effect. Testosterone (T), an important regulator of reproduction, and food availability are thus both potential factors regulating life-history processes, yet they are often tested in isolation of each other. In this study, we considered the effect of both food availability and elevated T on immune function and reproductive behavior in sagebrush lizards, Sceloporus graciosus, to assess how T and energy availability affect these trade-offs. We experimentally manipulated diet (via supplemental feedings) and T (via dermal patches) in males from a natural population. We determined innate immune response by calculating the bacterial killing capability of collected plasma exposed to Escherichia coli ex vivo. We measured reproductive behavior by counting the number of courtship displays produced in a 20-min sampling period. We observed an interactive effect of food availability and T-patch on immune function, with food supplementation increasing immunity in T-patch lizards. Additionally, T increased courtship displays in control food lizards. Lizards with supplemental food had higher circulating T than controls. Collectively, this study shows that the energetic state of the animal plays a critical role in modulating the interactions among T, behavior and immunity in sagebrush lizards and likely other species. Copyright 2009 Elsevier Inc. All rights reserved.

  9. Gary O's Fence Question.

    Science.gov (United States)

    Daniels, David S.

    1993-01-01

    Discusses the problem of finding the amount of fence it would require for the outfield fence of a baseball field of given dimensions. Presents different solution methods for each of the levels from grades 9-12. The different methods incorporate geometry, trigonometry, analytic geometry, and calculus. (MDH)

  10. Environmental Assessment for the MC-12 Training Squadron Beddown

    Science.gov (United States)

    2011-03-01

    Chelydra serpentina), eastern mud turtle (Kinosternon subrubrum), and yellow- bellied slider ( Trachemys scripta scipta). 3.2.5.2 Aquatic Communities...mountain garter snake (Thamnophis elegans elegans ), western pond turtle (Emys marmorata), western fence lizard (Sceloporus occidentalis

  11. Two new species of Parapharyngodon parasites of Sceloporus pyrocephalus, with a key to the species found in Mexico (Nematoda, Pharyngodonidae).

    Science.gov (United States)

    Garduño-Montes de Oca, Edgar Uriel; Mata-López, Rosario; León-Règagnon, Virginia

    2016-01-01

    Two new species of Parapharyngodon collected from the intestine of the Mexican boulder spiny lizard Sceloporus pyrocephalus are described. This study increases to 49 the number of valid species assigned to Parapharyngodon worldwide, 11 of them distributed in Mexico. Males of the two new species share the presence of four pairs of caudal papillae, an anterior echinate cloacal lip and the presence of lateral alae; however, both differ from each other in lateral alae extension and echinate cloacal anterior lip morphology. Females of both species have a prebulbar uterus and eggs shell punctuate with pores, characteristics shared with few other species of Parapharyngodon. Both new species differ from other congeneric species in the papillar arrangement, the anterior cloacal lip morphology, the lateral alae extension and total length/spicule ratio. A taxonomic key for the species of Parapharyngodon distributed in Mexico is provided.

  12. Egg retention and intrauterine embryonic development in Sceloporus aeneus (Reptilia: Phrynosomatidae: implications for the evolution of viviparity Retención de huevos y avance embrionario intrauterino en Sceloporus aeneus (Reptilia: Phrynosomatidae: implicaciones para la evolución de la viviparidad

    Directory of Open Access Journals (Sweden)

    Rodolfo García-Collazo

    2012-09-01

    Full Text Available Egg retention (ER and intrauterine embryonic development (IED have been considered intermediate steps in the evolution from oviparity to viviparity. Sceloporus aeneus is an oviparous lizard that is closely related to the viviparous species (Sceloporus bicanthalis. The present study addresses the following 2 questions: 1 Are intermediate stages of egg retention (ER and IED present in populations of Sceloporus aeneus? and 2 Are ER and/or IED explained by elevation, precipitation or phylogenetic effects? Results indicate that in S. aeneus, ER differs among populations. ER was negatively related to altitude and pluvial precipitation, whereas average environmental temperature had no effect on ER or IER. In contrast to previous observations of oviparous species related to viviparous species, populations of S. aeneus with advanced IED are associated with environmental factors such as low elevation and aridity instead of high elevation and cold climate, whereas the comparative analysis shows that there are no significative evolutionary changes throughout the phylogeny, which means that the altitude has no effect on the transition to the evolution of viviparity in S. aeneus-S bicanthalis.La retención de huevos (ER y el desarrollo embrionario intrauterino (IED han sido considerados pasos intermedios hacia la viviparidad. Sceloporus aeneus es un lacertilio ovíparo estrechamente relacionado a una especie vivípara (Sceloporus bicanthalis. El presente estudio derivó de las preguntas: ¿El ER y el IED presentes en las poblaciones de S. aeneus son estadios intermedios a la viviparidad? ¿ER y/o IED son explicados por la temperatura, altitud, precipitación pluvial o son un efecto filogenético? En S. aeneus, el ER y el IED fueron diferentes entre poblaciones. Los resultados indicaron que la ER se relacionó negativamente con la altitud y la precipitación pluvial, mientras que no se encontró efecto con la temperatura ambiental. En contraste con

  13. Comparative diet of three sympatric Sceloporus in the semiarid Zapotitlan Valley, Mexico Comparación de la dieta de tres especies simpátridas de Sceloporus en el valle semiárido de Zapotitlán, México

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Serrano-Cardozo

    2008-12-01

    Full Text Available Ecology, morphology, and phylogeny contribute to the organization of lizard assemblages; however, the number of lizard assemblages for which detailed knowledge of closely related sympatric species is available is limited. We studied the diet of 3 sympatric species of lizards (Sceloporus gadoviae, S. horridus, and S. jalapae from arid tropical scrub forest in Puebla, Mexico. These species prey primarily on arthropods, mostly termites, ants, and beetles. Spring and summer rains caused an increase in available prey biomass. However, lizards continued using the same resources throughout the study. These 3 species of Sceloporus are similar in their diet, especially the smaller bodied species, S. gadoviae and S. jalapae. Termites are a very important food for the 3 species throughout the year and are a major resource during the rainy season, which is not consistent with the hypothesis that many lizards eat termites only in the dry season.La ecología, morfología y la filogenia contribuyen a la organización de los ensambles de lagartijas. Sin embargo, son pocos los estudios detallados sobre la organización de estos ensambles y más aún, con especies simpátridas. Estudiamos la dieta, reproducción y dimorfismo sexual de 3 especies simpátridas de lagartijas (Sceloporus gadoviae, S. horridus, and S. jalapae de un matorral árido tropical en Puebla, México. Estas especies se alimentaron de artrópodos; principalmente de termitas, hormigas y escarabajos. Las lluvias de primavera y verano causaron un incremento en la biomasa de presas; sin embargo, las lagartijas continuaron usando los mismos recursos. Las lagartijas fueron especialistas consumiendo presas en relación a su abundancia. Las 3 especies fueron similares en su dieta, especialmente las especies pequeñas S. gadoviae y S. jalapae. Las termitas son un importante recurso para estas 3 especies durante el todo año y la principal fuente alimenticia en la estación lluviosa, lo cual no es

  14. Are Invasive Species Stressful? The Glucocorticoid Profile of Native Lizards Exposed to Invasive Fire Ants Depends on the Context.

    Science.gov (United States)

    Graham, Sean P; Freidenfelds, Nicole A; Thawley, Christopher J; Robbins, Travis R; Langkilde, Tracy

    Invasive species represent a substantial threat to native species worldwide. Research on the impacts of invasive species on wild living vertebrates has focused primarily on population-level effects. The sublethal, individual-level effects of invaders may be equally important but are poorly understood. We investigated the effects of invasive fire ants (Solenopsis invicta) on the physiological stress response of a native lizard (Sceloporus undulatus) within two experimental contexts: directly exposing lizards to a fire ant attack and housing lizards with fire ants in seminatural field enclosures. Lizards directly exposed to brief attack by fire ants had elevated concentrations of the stress hormone corticosterone (CORT), suggesting that these encounters can be physiologically stressful. However, lizards exposed for longer periods to fire ants in field enclosures had lower concentrations of CORT. This may indicate that the combined effects of confinement and fire ant exposure have pushed lizards into allostatic overload. However, lizards from fire ant enclosures appeared to have intact negative feedback controls of the stress response, evidenced by functioning adrenocorticotropic hormone responsiveness and lack of suppression of innate immunity (plasma bactericidal capacity). We review previous studies examining the stress response of wild vertebrates to various anthropogenic stressors and discuss how these-in combination with our results-underscore the importance of considering context (the length, frequency, magnitude, and types of threat) when assessing these impacts.

  15. Conserved sex chromosomes across adaptively radiated Anolis lizards.

    Science.gov (United States)

    Rovatsos, Michail; Altmanová, Marie; Pokorná, Martina; Kratochvíl, Lukáš

    2014-07-01

    Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  16. Would behavioral thermoregulation enable pregnant viviparous tropical lizards to cope with a warmer world?

    Science.gov (United States)

    López-Alcaide, Saúl; Nakamura, Miguel; Smith, Eric N; Martínez-Meyer, Enrique

    2017-09-01

    Sceloporus lizards depend on external heat to achieve their preferred temperature (T sel ) for performing physiological processes. Evidence both in the field and laboratory indicates that pregnant females of this Genus select body temperatures (T b ) lower than 34 °C as higher temperatures may be lethal to embryos. Therefore, thermoregulation is crucial for successful embryo development. Given the increase in global air temperature, it is expected that the first compensatory response of species that inhabit tropical climates will be behavioral thermoregulation. We tested whether viviparous Sceloporus formosus group lizards in the wild exhibited differences in thermoregulatory behavior to achieve the known T sel for developing embryos regardless of local thermal conditions. We quantified field active body temperature, thermoregulatory behavior mechanisms (time of sighting, microhabitat used and basking time) and available microhabitat thermal conditions (i.e. operative temperature) for 10 lizard species during gestation, distributed along an altitudinal gradient. We applied both conventional and phylogenic analyses to explore whether T b or behavioral thermoregulation could be regulated in response to different thermal conditions. These species showed no significant differences in field T b during gestation regardless of local thermal conditions. In contrast, they exhibited significant differences in their behavioral thermoregulation associated with local environmental conditions. Based on these observations, the differences in thermoregulatory behavior identified are interpreted as compensatory adjustments to local thermal conditions. We conclude that these species may deal with higher temperatures predicted for the tropics by modulating their thermoregulatory behavior. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  17. Communication Signals in Lizards.

    Science.gov (United States)

    Carpenter, Charles C.

    1983-01-01

    Discusses mechanisms and functional intent of visual communication signals in iguanid/agamid lizards. Demonstrated that lizards communicate with each other by using pushups and head nods and that each species does this in its own way, conveying different types of information. (JN)

  18. Maritime Geo-Fence Letter Report

    Science.gov (United States)

    2016-07-01

    1 Classification | CG-926 RDC | author | audience | month year Maritime Geo-Fence Letter Report Authors: Irene Gonin and Gregory...Johnson   Distribution Statement A: Approved for public release; distribution is unlimited. July 2016 Report No. CG-D-10-16 Maritime Geo-Fence...United States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 Maritime Geo-Fence Letter Report 1

  19. Residential fencing in a metropolitan area and three small towns.

    Science.gov (United States)

    Edwin Kallio; Jerry A. Sesco

    1967-01-01

    Many types of fences were found on residential lots in the metropolitan-suburban area of St. Louis County, Missouri, and three small towns in southern Illinois. Wire fences predominated. More wooden fences were found on village lots than on city lots. In general, the more expensive homes had the most wooden fencing. Homes over 5 years old had more fencing of all...

  20. Reproductive Medicine in Lizards.

    Science.gov (United States)

    Knotek, Zdenek; Cermakova, Eva; Oliveri, Matteo

    2017-05-01

    Common reproductive problems in captive male lizards are hemipenile plugs in hemipenial sac, unilateral prolapse of hemipenis, or bilateral prolapse of hemipene. Although the orchiectomy is performed as a treatment for testicular disease, the effectiveness in reducing aggressive behavior is unclear. Female captive lizards suffer from cloacal prolapse, preovulatory follicular stasis, or dystocia. The veterinarian must differentiate between the disorders because the treatment differs. Mating, physical, or visual contact with the male stimulates ovulation and prevents preovulatory follicular stasis. Surgical intervention is usually required for dystocia. This article discusses selected procedures and use of ultrasonography and diagnostic endoscopy. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Evaluation of predator-proof fenced biodiversity projects

    OpenAIRE

    Doelle, Sebastian

    2012-01-01

    There has been recent debate over the role of predator-proof fences in the management of New Zealand’s biodiversity. The debate has arisen due to concern that investments in fenced sanctuaries are less productive than are alternative ways to manage biodiversity. Predator-proof fences are costly and budget constraints limit the area of habitat that can be fenced. The area of habitat enclosed within fences, and number of individuals of species supported, determines project’s ability to contribu...

  2. Notes on Scincid Lizards

    NARCIS (Netherlands)

    Brongersma, L.D.

    1942-01-01

    Lygosoma (Sphenomorphus) florense barbouri Dunn (Pl. VI fig. 1) Sphenomorphus florense barbouri Dunn, Amer. Mus. Nov., no. 288, 1927, p. 5, and Dunn, in: Burden, Dragon Lizards of Komodo, 1927, p. 203. 1 ♂, Noil Toko, Timor, 1937, leg. P. F. van West, Mus. Leiden, reg. no. 7033. 5 ♂ ♂, 6 ♀ ♀, Timor,

  3. Improving reptile ecological risk assessment: oral and dermal toxicity of pesticides to a common lizard species (Sceloporus occidentalis).

    Science.gov (United States)

    Weir, Scott M; Yu, Shuangying; Talent, Larry G; Maul, Jonathan D; Anderson, Todd A; Salice, Christopher J

    2015-08-01

    Reptiles have been understudied in ecotoxicology, which limits consideration in ecological risk assessments. The goals of the present study were 3-fold: to improve oral and dermal dosing methodologies for reptiles, to generate reptile toxicity data for pesticides, and to correlate reptile and avian toxicity. The authors first assessed the toxicity of different dosing vehicles: 100 μL of water, propylene glycol, and acetone were not toxic. The authors then assessed the oral and dermal toxicity of 4 pesticides following the up-and-down procedure. Neither brodifacoum nor chlorothalonil caused mortality at doses ≤ 1750 μg/g. Under the "neat pesticide" oral exposure, endosulfan (median lethal dose [LD50] = 9.8 μg/g) was more toxic than λ-cyhalothrin (LD50 = 916.5 μg/g). Neither chemical was toxic via dermal exposure. An acetone dosing vehicle increased λ-cyhalothrin toxicity (oral LD50 = 9.8 μg/g; dermal LD50 = 17.5 μg/g), but not endosulfan. Finally, changes in dosing method and husbandry significantly increased dermal λ-cyhalothrin LD50s, which highlights the importance of standardized methods. The authors combined data from the present study with other reptile LD50s to correlate with available avian data. When only definitive LD50s were used in the analysis, a strong correlation was found between avian and reptile toxicity. The results suggest it is possible to build predictive relationships between avian and reptile LD50s. More research is needed, however, to understand trends associated with chemical classes and modes of action. © 2015 SETAC.

  4. A Braitenberg Lizard:

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    2009-01-01

    The peripheral auditory system of a lizard is structured as a pressure difference receiver with strong broadband directional sensitivity. Previous work has demonstrated that this system can be implemented as a set of digital filters generated by considering the lumped-parameter model of the audit......The peripheral auditory system of a lizard is structured as a pressure difference receiver with strong broadband directional sensitivity. Previous work has demonstrated that this system can be implemented as a set of digital filters generated by considering the lumped-parameter model...... of the auditory system, and can be used successfully for step control steering of mobile robots. We extend the work to the continuous steering case, implementing the same model on a Braitenberg vehicle-like robot. The performance of the robot is evaluated in a phonotaxis task. The robot shows strong directional...

  5. Lizard reproductive medicine and surgery.

    Science.gov (United States)

    Funk, Richard S

    2002-09-01

    Lizards are a diverse group of some 4470 species, a wide variety of which are now kept in captivity. Interest in captive lizards continues to increase, wild populations seem to be declining in some areas, and herpetoculturists continue to succeed in breeding more species; consequently, veterinarians must understand basic lizard reproductive biology to successfully treat lizard patients with reproductive problems. Just obtaining First Filial Generation (F1) offspring is an accomplishment. But we must look down the road to maintain a species in captivity for succeeding generations, and a lineage may not continue if attention is not given to details of appropriate husbandry and proper reproductive pursuits. One study documents the senescence of lineages in parthenogenetic lizards in captivity apparently associated with husbandry problems [99].

  6. Stream-crossing structure for deer fence

    Science.gov (United States)

    Robert M. Blair; James A. Hays; Louis Brunett

    1963-01-01

    Stream crossings are the most vulnerable points in a deer-proof fence. When an inadequately constructed crossing washes out, enclosed deer may escape and unwanted animals enter. Structures of the type described here have withstood 2 years of frequent, severe flooding in the pine-hardwood hills of central Louisiana.

  7. Game fence presence and permeability influences the local ...

    African Journals Online (AJOL)

    Fences are utilised throughout the world to restrict the movements of wildlife, protecting them from threats and reducing human–wildlife conflict. In South Africa the number of privately-owned fenced game reserves has greatly increased in recent years, but little is known about how fencing affects the distribution and ...

  8. Assessment and placement of living snow fences to reduce highway maintenance costs and improve safety (living snow fences).

    Science.gov (United States)

    2015-05-01

    Living snow fences (LSF) are designed plantings of trees and/or shrubs and native grasses along highways, roads : and ditches that create a vegetative buffer that traps and controls blowing and drifting snow. These strategically : placed fences have ...

  9. New records of helminths of Sceloporus pyrocephalus Cope (Squamata, Phrynosomatidae) from Guerrero and Michoacán, Mexico, with the description of a new species of Thubunaea Seurat, 1914 (Nematoda, Physalopteridae).

    Science.gov (United States)

    de Oca, Edgar Uriel Garduño-Montes; López-Caballero, Jorge D; Mata-López, Rosario

    2017-01-01

    A total of 61 specimens of the Red-headed Spiny Lizard Sceloporus pyrocephalus Cope (Phrynosomatidae) collected during the breeding season (June/July 2003, 2004 and 2005) from Western Mexico were examined for helminths. The morphological characterization of the helminths found was made through light microscopy and scanning electron microscopy. Nine taxa of helminths were identified, two cestodes: Mesocestoides sp. and Oochoristica sp., and seven nematodes: Parapharyngodon ayotzinapaensis Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon tikuinii Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon sp., Physalopterinae gen. sp., Skrjabinoptera scelopori Caballero-Rodríguez, 1971, Strongyluris similis Caballero, 1938 and a new species of Thubunaea Seurat, 1914. Larvae of Mesocestoides sp. and Physalopterinae gen. sp. were found in the body cavity and digestive tract, respectively. Excluding the species of Parapharyngodon Chatterji, 1933, S. pyrocephalus is recorded for the first time as a host of the remaining seven taxa of helminths. Additionally, Thubunaea leonregagnonae sp. n. is described and illustrated as a new nematode species, parasite of S. pyrocephalus from Mexico. This new species can be differentiated from the majority of its congeners by the absence of spicules, the particular pattern of caudal papillae in males and the small ratio of oesophagus length:male total body length (0.1-0.16).

  10. New records of helminths of Sceloporus pyrocephalus Cope (Squamata, Phrynosomatidae from Guerrero and Michoacán, Mexico, with the description of a new species of Thubunaea Seurat, 1914 (Nematoda, Physalopteridae

    Directory of Open Access Journals (Sweden)

    Edgar Uriel Garduño-Montes de Oca

    2017-11-01

    Full Text Available A total of 61 specimens of the Red-headed Spiny Lizard Sceloporus pyrocephalus Cope (Phrynosomatidae collected during the breeding season (June/July 2003, 2004 and 2005 from Western Mexico were examined for helminths. The morphological characterization of the helminths found was made through light microscopy and scanning electron microscopy. Nine taxa of helminths were identified, two cestodes: Mesocestoides sp. and Oochoristica sp., and seven nematodes: Parapharyngodon ayotzinapaensis Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon tikuinii Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon sp., Physalopterinae gen. sp., Skrjabinoptera scelopori Caballero-Rodríguez, 1971, Strongyluris similis Caballero, 1938 and a new species of Thubunaea Seurat, 1914. Larvae of Mesocestoides sp. and Physalopterinae gen. sp. were found in the body cavity and digestive tract, respectively. Excluding the species of Parapharyngodon Chatterji, 1933, S. pyrocephalus is recorded for the first time as a host of the remaining seven taxa of helminths. Additionally, Thubunaea leonregagnonae sp. n. is described and illustrated as a new nematode species, parasite of S. pyrocephalus from Mexico. This new species can be differentiated from the majority of its congeners by the absence of spicules, the particular pattern of caudal papillae in males and the small ratio of oesophagus length:male total body length (0.1–0.16.

  11. Effects of sand fences on coastal dune vegetation distribution

    Science.gov (United States)

    Grafals-Soto, Rosana

    2012-04-01

    Sand fences are important human adjustments modifying the morphology of developed shores. The effects of sand fences on sediment transport and deposition in their initial stages have been well studied, but little is known about the effect of deteriorated sand fences that have become partially buried low scale barriers within the dune, potentially benefiting vegetation growth by protecting it from onshore stress. Data on vegetation, topography and fence characteristics were gathered at three dune sites in Ocean City, New Jersey on September 2007 and March 2008 to evaluate the effect of fences within the dune on vegetation distribution. Variables include: distance landward of dune toe, degree of sheltering from onshore stressors, net change in surface elevation (deposition or erosion), vegetation diversity and density, presence of remnant fence, and distance landward of fence. Results for the studied environment reveal that 1) vegetation diversity or density does not increase near remnant fences because most remnants are lower than average vegetation height and can not provide shelter; but 2) vegetation distribution is related to topographic variables, such as degree of sheltering, that are most likely the result of sand accretion caused by fence deployment. Fence deployment that prioritizes the creation of topographically diverse dunes within a restricted space may increase the diversity and density of the vegetation, and the resilience and value of developed dunes. Managers should consider the benefits of using sand fences on appropriately wide beaches to create a protective dune that is also diverse, functional and better able to adapt to change.

  12. Sterility among female lizards (Uta stansburiana) exposed to continuous γ irradiation

    International Nuclear Information System (INIS)

    Turner, F.B.; Medica, P.A.

    1977-01-01

    A natural population of the lizard Uta stansburiana occupying a fenced 9-ha area in southern Nevada was exposed to essentially continuous γ irradiation from an arificial source between February 1964 and September 1973. Tissue doses were estimated using implanted lithium fluoride microdosimeters. Females became sterile as early as 11 months of age, but many were still fertile at ages of 20 months and a very few may have reproduced at 32 months. Dosimetry showed some females to be sterile after accumulated doses of around 500 rad, while others may have required 1000 or more rad. One female estimated to have received over 1200 rad was still reproductive. Irradiated females may pass through a state of half sterility, during which time they possess one functional ovary. Female U. stansburiana are sterilized at lower doses than the sterilizing dose (1500 rad) previously suggested for the leopard lizard, Crotaphytus wislizenii

  13. national fencing team – the sabre event

    Directory of Open Access Journals (Sweden)

    Władysław Jagiełło

    2017-12-01

    Full Text Available Fencing is a combat sport whose form of direct confrontation involves hitting the opponent with a weapon. The purpose of the study was to determine the properties of body composition of female representatives of the Polish national fencing team. The study involved 11 female athletes of the Polish national fencing team. Their age was 16-22 years (19±2.32, body weight 52-78 kg (59.7±7.4, body height 158-183 cm (167.46±6.10 and the training experience 7.64±3.47 years. The reference group consisted of 153 students of Warsaw University of Technology (Poland. Twenty basic somatic characteristics were measured. The following indices were calculated: slenderness, Rohrer’s, BMI, Manouvrier’s, and pelvic-shoulder indices. Density of the body, total body fat, active tissue, the overall profile of body composition and internal proportions of the body were determined. Analysis of internal proportions of factors of the athletes’ body composition revealed significant differences in particular groups of features. The total size of the athletes’ bodies is due to less-than-average magnitude of the length and stoutness characteristics and a high magnitude of adiposity (M = 0.63 in the Polish female national team of fencers (sabre calculated from the normalized values for the control group. The proportions of features within the analysed factors revealed a significant advantage of the length of the upper extremity over the lower one and a distinct advantage of forearm musculature. The specific profile of body composition of female athletes practising sabre fencing is most likely due to long-term effects of training as well as the system of selection of persons with specific somatic prerequisites developed in the course of many years of training practice.

  14. Conserving large carnivores: dollars and fence.

    Science.gov (United States)

    Packer, C; Loveridge, A; Canney, S; Caro, T; Garnett, S T; Pfeifer, M; Zander, K K; Swanson, A; Macnulty, D; Balme, G; Bauer, H; Begg, C M; Begg, K S; Bhalla, S; Bissett, C; Bodasing, T; Brink, H; Burger, A; Burton, A C; Clegg, B; Dell, S; Delsink, A; Dickerson, T; Dloniak, S M; Druce, D; Frank, L; Funston, P; Gichohi, N; Groom, R; Hanekom, C; Heath, B; Hunter, L; Deiongh, H H; Joubert, C J; Kasiki, S M; Kissui, B; Knocker, W; Leathem, B; Lindsey, P A; Maclennan, S D; McNutt, J W; Miller, S M; Naylor, S; Nel, P; Ng'weno, C; Nicholls, K; Ogutu, J O; Okot-Omoya, E; Patterson, B D; Plumptre, A; Salerno, J; Skinner, K; Slotow, R; Sogbohossou, E A; Stratford, K J; Winterbach, C; Winterbach, H; Polasky, S

    2013-05-01

    Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km(-2) , unfenced populations require budgets in excess of $2000 km(-2) to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density-independent factors. Nearly half the unfenced lion populations may decline to near extinction over the next 20-40 years. © 2013 Blackwell Publishing Ltd/CNRS.

  15. Fencing the forest: early use of barrier fences in Sami reindeer husbandry

    Directory of Open Access Journals (Sweden)

    Gudrun Norstedt

    2017-10-01

    Full Text Available Barrier fences are generally not considered to have been used in Sami reindeer husbandry in Sweden before the early 20th century. As a rule, they are thought to have been introduced with the transition from intensive to extensive herding that is assumed to have taken place at this time. However, in this study, we show that barrier fences were widely used in Gällivare, Jokkmokk and Arjeplog Municipalities from the mid-18th century onwards, especially in the forests. Until the early 20th century, these fences were built of local materials, mainly whole trees and boulders, and we therefore call them whole-tree fences. Some of the barrier fences were used during periods of loose supervision by herders who otherwise practised intensive methods, while others were built in a context of extensive herding, large herds and conflicts over land use. Extensive reindeer herding was thus practised in the area much earlier than usually presumed, and it overlapped with intensive herding in both time and space.

  16. Controlling Within-Field Sheep Movement Using Virtual Fencing.

    Science.gov (United States)

    Marini, Danila; Llewellyn, Rick; Belson, Sue; Lee, Caroline

    2018-02-26

    Virtual fencing has the potential to greatly improve livestock movement, grazing efficiency, and land management by farmers; however, relatively little work has been done to test the potential of virtual fencing with sheep. Commercial dog training equipment, comprising of a collar and GPS hand-held unit were used to implement a virtual fence in a commercial setting. Six, 5-6 year-old Merino wethers, which were naïve to virtual fencing were GPS tracked for their use of a paddock (80 × 20 m) throughout the experiment. The virtual fence was effective at preventing a small group of sheep from entering the exclusion zone. The probability of a sheep receiving an electrical stimulus following an audio cue was low (19%), and declined over the testing period. It took an average of eight interactions with the fence for an association to be made between the audio and stimulus cue, with all of the animals responding to the audio alone by the third day. Following the removal of the virtual fence, sheep were willing to cross the previous location of the virtual fence after 30 min of being in the paddock. This is an important aspect in the implementation of virtual fencing as a grazing management tool and further enforces that the sheep in this study were able to associate the audio with the virtual fence and not the physical location itself.

  17. Acoustical coupling of lizard eardrums

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Manley, Geoffrey A

    2008-01-01

    Lizard ears are clear examples of two-input pressure-difference receivers, with up to 40-dB differences in eardrum vibration amplitude in response to ipsi- and contralateral stimulus directions. The directionality is created by acoustical coupling of the eardrums and interaction of the direct...... and indirect sound components on the eardrum. The ensuing pressure-difference characteristics generate the highest directionality of any similar-sized terrestrial vertebrate ear. The aim of the present study was to measure the gain of the direct and indirect sound components in three lizard species: Anolis...... sagrei and Basiliscus vittatus (iguanids) and Hemidactylus frenatus (gekkonid) by laser vibrometry, using either free-field sound or a headphone and coupler for stimulation. The directivity of the ear of these lizards is pronounced in the frequency range from 2 to 5 kHz. The directivity is ovoidal...

  18. Trajectories of saltating sand particles behind a porous fence

    Science.gov (United States)

    Zhang, Ning; Lee, Sang Joon; Chen, Ting-Guo

    2015-01-01

    Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a 'no-fence' case. A wind fence (ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles.

  19. Minimizing species extinctions through strategic planning for conservation fencing.

    Science.gov (United States)

    Ringma, Jeremy L; Wintle, Brendan; Fuller, Richard A; Fisher, Diana; Bode, Michael

    2017-10-01

    Conservation fences are an increasingly common management action, particularly for species threatened by invasive predators. However, unlike many conservation actions, fence networks are expanding in an unsystematic manner, generally as a reaction to local funding opportunities or threats. We conducted a gap analysis of Australia's large predator-exclusion fence network by examining translocation of Australian mammals relative to their extinction risk. To address gaps identified in species representation, we devised a systematic prioritization method for expanding the conservation fence network that explicitly incorporated population viability analysis and minimized expected species' extinctions. The approach was applied to New South Wales, Australia, where the state government intends to expand the existing conservation fence network. Existing protection of species in fenced areas was highly uneven; 67% of predator-sensitive species were unrepresented in the fence network. Our systematic prioritization yielded substantial efficiencies in that it reduced expected number of species extinctions up to 17 times more effectively than ad hoc approaches. The outcome illustrates the importance of governance in coordinating management action when multiple projects have similar objectives and rely on systematic methods rather than expanding networks opportunistically. © 2017 Society for Conservation Biology.

  20. Evaluation of filter fabrics for use in silt fences.

    Science.gov (United States)

    1980-01-01

    The study reported was initiated to develop tests simulating field conditions that could be used to develop information for the formulation of specifications for use in purchasing filter fabrics to be used to construct silt fences. Fifteen fabrics we...

  1. Historical fencing and scientific research medieval weapons: common ground

    Directory of Open Access Journals (Sweden)

    B. V. Hrynchyshyn

    2015-07-01

    We considered various approaches to the reconstruction of the historical fencing. It is proved that the activities of such societies has a positive effect on the process research of features of medieval weapons, fighting tactics of different periods The various approaches to the reconstruction of the historical fencing. Proved that the activities of such societies has a positive effect on the process research of features of medieval weapons, fighting tactics of different periods.

  2. CFD Analysis of a T-38 Wing Fence

    Science.gov (United States)

    2007-06-01

    or making major adjustments to the existing airframe. The answer lies in flow control. Flow control devices like vortex generators, winglets , and wing...fences have been used to improve the aerodynamic performance of hundreds of aircraft. Flow control is commonly added after the final phase of design...proposed by the Air Force Test Pilot School. The driving force for considering a wing fence as opposed to vane vortex generators or winglets 3 was a row of

  3. Foot loading characteristics during three fencing-specific movements.

    Science.gov (United States)

    Trautmann, Caroline; Martinelli, Nicolo; Rosenbaum, Dieter

    2011-12-01

    Plantar pressure characteristics during fencing movements may provide more specific information about the influence of foot loading on overload injury patterns. Twenty-nine experienced fencers participated in the study. Three fencing-specific movements (lunge, advance, retreat) and normal running were performed with three different shoe models: Ballestra (Nike, USA), Adistar Fencing Lo (Adidas, Germany), and the fencers' own shoes. The Pedar system (Novel, Munich, Germany) was used to collect plantar pressures at 50 Hz. Peak pressures, force-time integrals and contact times for five foot regions were compared between four athletic tasks in the lunge leg and supporting leg. Plantar pressure analysis revealed characteristic pressure distribution patterns for the fencing movements. For the lunge leg, during the lunge and advance movements the heel is predominantly loaded; during retreat, it is the hallux. For the supporting leg, during the lunge and advance movements the forefoot is predominantly loaded; during retreat, it is the hallux. Fencing-specific movements load the plantar surface in a distinct way compared with running. An effective cushioning in the heel and hallux region would help to minimize foot loading during fencing-specific movements.

  4. Lizard locomotion in heterogeneous granular media

    Science.gov (United States)

    Schiebel, Perrin; Goldman, Daniel

    2014-03-01

    Locomotion strategies in heterogeneous granular environments (common substrates in deserts), are relatively unexplored. The zebra-tailed lizard (C. draconoides) is a useful model organism for such studies owing to its exceptional ability to navigate a variety of desert habitats at impressive speed (up to 50 body-lengths per second) using both quadrapedal and bidepal gaits. In laboratory experiments, we challenge the lizards to run across a field of boulders (2.54 cm diameter glass spheres or 3.8 cm 3D printed spheres) placed in a lattice pattern and embedded in a loosely packed granular medium of 0.3 mm diameter glass particles. Locomotion kinematics of the lizard are recorded using high speed cameras, with and without the scatterers. The data reveals that unlike the lizard's typical quadrupedal locomotion using a diagonal gait, when scatterers are present the lizard is most successful when using a bipedal gait, with a raised center of mass (CoM). We propose that the kinematics of bipedal running in conjunction with the lizard's long toes and compliant hind foot are the keys to this lizard's successful locomotion in the presence of such obstacles. NSF PoLS

  5. Unique structural features facilitate lizard tail autotomy.

    Science.gov (United States)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise; Vinding, Mads S; Rydtoft, Louise M; Mortensen, Martin B; Karring, Henrik; Nielsen, Niels Chr; Wang, Tobias; Thøgersen, Ida B; Enghild, Jan J

    2012-01-01

    Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  6. Unique structural features facilitate lizard tail autotomy

    DEFF Research Database (Denmark)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise

    2012-01-01

    Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed...... that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail...

  7. Gender differences in patellofemoral load during the epee fencing lunge.

    Science.gov (United States)

    Sinclair, J; Bottoms, L

    2015-01-01

    Clinical analyses have shown that injuries and pain linked specifically to fencing training/competition were prevalent in 92.8% of fencers. Patellofemoral pain is the most common chronic injury in athletic populations and females are considered to be more susceptible to this pathology. This study aimed to examine gender differences in patellofemoral contact forces during the fencing lunge. Patellofemoral contact forces were obtained from eight male and eight female club level epee fencers using an eight-camera 3D motion capture system and force platform data as they completed simulated lunges. Independent t-tests were performed on the data to determine whether gender differences in patellofemoral contact forces were present. The results show that females were associated with significantly greater patellofemoral contact force parameters in comparison with males. This suggests that female fencers may be at greater risk from patellofemoral pathology as a function of fencing training/competition.

  8. Performance Evaluations of Three Silt Fence Practices Using a Full-Scale Testing Apparatus

    Directory of Open Access Journals (Sweden)

    R. Alan Bugg

    2017-07-01

    Full Text Available Erosion and sediment controls on construction sites minimize environmental impacts from sediment-laden stormwater runoff. Silt fence, a widely specified perimeter control practice on construction projects used to retain sediment on-site, has limited performance-based testing data. Silt fence failures and resultant sediment losses are often the result of structural failure. To better understand silt fence performance, researchers at the Auburn University-Erosion and Sediment Control Testing Facility (AU-ESCTF have evaluated three silt fence options to determine possible shortcomings using standardized full-scale testing methods. These methods subject silt fence practices to simulated, in-field conditions typically experienced on-site without the variability of field testing or the limited application of small-scale testing. Three different silt fence practices were tested to evaluate performance, which included: (1 Alabama Department of Transportation (ALDOT Trenched Silt Fence, (2 ALDOT Sliced Silt Fence, and (3 Alabama Soil and Water Conservation Committee (AL-SWCC Trenched Silt Fence. This study indicates that the structural performance of a silt fence perimeter control is the most important performance factor in retaining sediment. The sediment retention performance of these silt fence practices was 82.7%, 66.9% and 90.5%, respectively. When exposed to large impoundment conditions, both ALDOT Trench and Sliced Silt Fence practices failed structurally, while the AL-SWCC Trenched Silt Fence did not experience structural failure.

  9. Conservation of sex chromosomes in lacertid lizards

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Vukič, J.; Altmanová, M.; Johnson Pokorná, Martina; Moravec, J.; Kratochvíl, L.

    2016-01-01

    Roč. 25, č. 13 (2016), s. 3120-3126 ISSN 0962-1083 Institutional support: RVO:67985904 Keywords : lizards * molecular sex ing * reptiles * sex chromosomes Subject RIV: EG - Zoology Impact factor: 6.086, year: 2016

  10. Effectiveness of electro-fencing for restricting the ranging behaviour ...

    African Journals Online (AJOL)

    Here, we assessed the effectiveness of electro-fencing for restricting movement patterns of several wild ungulates in Akagera National Park (NP), Rwanda. Following the turmoil of the Rwandan genocide and civil war (1991–1995), large numbers of returning war refugees brought about an increasing pressure on land use, ...

  11. Silt fences: An economical technique for measuring hillslope soil erosion

    Science.gov (United States)

    Peter R. Robichaud; Robert E. Brown

    2002-01-01

    Measuring hillslope erosion has historically been a costly, time-consuming practice. An easy to install low-cost technique using silt fences (geotextile fabric) and tipping bucket rain gauges to measure onsite hillslope erosion was developed and tested. Equipment requirements, installation procedures, statistical design, and analysis methods for measuring hillslope...

  12. Teaching Electric Fences: The Physics behind the Brainiac Video

    Science.gov (United States)

    Vollmer, Michael

    2016-01-01

    In many states, electric fences are used to prevent animals from leaving a designated area, for example for grazing. They are quite well known by most students and can therefore serve as daily-life examples of electric circuits. Besides helping to grasp the ideas of Kirchhoff's laws for voltages and currents in circuits according to loop and…

  13. "Rabbit Proof Fence": A Struggle for Cultural Existence

    Science.gov (United States)

    Al-Momani, Hassan Ali Abdullah

    2016-01-01

    The main goal of this paper is to depict the struggle for cultural existence in "Rabbit Proof Fence." It also reflects the cultural conflict represented in the three aboriginal girls' characters which is due to their rejection and resistance for the colonialists' culture. Besides, the paper presents the cognitive analysis of the cultural…

  14. The fence experiment - a first evaluation of shelter models

    DEFF Research Database (Denmark)

    Peña, Alfredo; Bechmann, Andreas; Conti, Davide

    2016-01-01

    We present a preliminary evaluation of shelter models of different degrees of complexity using full-scale lidar measurements of the shelter on a vertical plane behind and orthogonal to a fence. Model results accounting for the distribution of the relative wind direction within the observed direct...

  15. Lesser prairie-chicken fence collision risk across its northern distribution

    Science.gov (United States)

    Robinson, Samantha G.; Haukos, David A.; Plumb, Reid T.; Hagen, Christian A.; Pitman, James C.; Lautenbach, Joseph M.; Sullins, Daniel S.; Kraft, John D.; Lautenbach, Jonathan D.

    2016-01-01

    Livestock fences have been hypothesized to significantly contribute to mortality of lesser prairie-chickens (Tympanuchus pallidicinctus); however, quantification of mortality due to fence collisions is lacking across their current distribution. Variation in fence density, landscape composition and configuration, and land use could influence collision risk of lesser prairie-chickens. We monitored fences within 3 km of known leks during spring and fall and surveyed for signs of collision occurrence within 20 m of fences in 6 study sites in Kansas and Colorado, USA during 2013 and 2014. We assessed mortality locations of radio-tagged birds (n = 286) for evidence of fence collisions and compared distance to fence relative to random points. Additionally, we quantified locations, propensity, and frequency of fences crossed by lesser prairie-chickens. We tested for landscape and vegetative characteristics that influenced fence-cross propensity and frequency of global positioning system (GPS)-marked birds. A minimum of 12,706 fence crossings occurred by GPS-marked lesser prairie-chickens. We found 3 carcasses and 12 additional possible instances of evidence of collision during >2,800 km of surveyed fences. We found evidence for a single suspected collision based on carcass evidence for 148 mortalities of transmittered birds. Mortality locations of transmittered birds were located at distances from fences 15% farther than expected at random. Our data suggested minimal biological significance and indicated that propensity and frequency of fence crossings were random processes. Lesser prairie-chickens do not appear to be experiencing significant mortality risk due to fence collisions in Kansas and Colorado. Focusing resources on other limiting factors (i.e., habitat quality) has greater potential for impact on population demography than fence marking and removal.

  16. Detusking fence-breaker elephants as an approach in human-elephant conflict mitigation.

    Science.gov (United States)

    Mutinda, Matthew; Chenge, Geoffrey; Gakuya, Francis; Otiende, Moses; Omondi, Patrick; Kasiki, Samuel; Soriguer, Ramón C; Alasaad, Samer

    2014-01-01

    Human-elephant conflict (HEC) is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers). In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana) were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking) per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks) in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking) by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food. Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated.

  17. Detusking fence-breaker elephants as an approach in human-elephant conflict mitigation.

    Directory of Open Access Journals (Sweden)

    Matthew Mutinda

    Full Text Available Human-elephant conflict (HEC is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers.In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food.Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated.

  18. The medical care of iguanas and other common pet lizards.

    Science.gov (United States)

    Barten, S L

    1993-11-01

    The majority of health problems in captive lizards result from improper diets, caging, and environmental conditions. This article discusses recommended husbandry and management techniques. A clinical approach to evaluating the health status of lizards, including assessing patient history, physical examination, clinical pathology, anesthesia, and surgery, is reviewed. Common health maladies of captive lizards are discussed, and rapid diagnosis and treatment are emphasized.

  19. A Look over the Fence - The Psychology of Religion

    OpenAIRE

    Böhmer, Annegret

    2010-01-01

    Psychological Theories in the Discussion on Instruction in Ethics A Look over the Fence - The Psychology of Religion Annegret Böhmer Children and adolescents are supposed to be given the opportunity in school not only to acquire knowledge and skills, but also to develop their identity and receive assistance in leading a successful life. In the Federal Republic of Germany it long remained an undisputed fact that religious instruction was responsible for the latter. According to Ar...

  20. Unique structural features facilitate lizard tail autotomy.

    Directory of Open Access Journals (Sweden)

    Kristian W Sanggaard

    Full Text Available Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed that tail shedding by the Tokay gecko (Gekko gecko and the associated extracellular matrix (ECM rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  1. Perpetuation of the Lyme Disease Spirochete Borrelia lusitaniae by Lizards

    Science.gov (United States)

    Richter, Dania; Matuschka, Franz-Rainer

    2006-01-01

    To determine whether the Lyme disease spirochete Borrelia lusitaniae is associated with lizards, we compared the prevalence and genospecies of spirochetes present in rodent- and lizard-associated ticks at a site where this spirochete frequently infects questing ticks. Whereas questing nymphal Ixodes ricinus ticks were infected mainly by Borrelia afzelii, one-half of the infected adult ticks harbored B. lusitaniae at our study site. Lyme disease spirochetes were more prevalent in sand lizards (Lacerta agilis) and common wall lizards (Podarcis muralis) than in small rodents. Although subadult ticks feeding on rodents acquired mainly B. afzelii, subadult ticks feeding on lizards became infected by B. lusitaniae. Genetic analysis confirmed that the spirochetes isolated from ticks feeding on lizards are members of the B. lusitaniae genospecies and resemble type strain PotiB2. At our central European study site, lizards, which were previously considered zooprophylactic for the agent of Lyme disease, appear to perpetuate B. lusitaniae. PMID:16820453

  2. A stem acrodontan lizard in the Cretaceous of Brazil revises early lizard evolution in Gondwana.

    Science.gov (United States)

    Simões, Tiago R; Wilner, Everton; Caldwell, Michael W; Weinschütz, Luiz C; Kellner, Alexander W A

    2015-08-26

    Iguanians are one of the most diverse groups of extant lizards (>1,700 species) with acrodontan iguanians dominating in the Old World, and non-acrodontans in the New World. A new lizard species presented herein is the first acrodontan from South America, indicating acrodontans radiated throughout Gondwana much earlier than previously thought, and that some of the first South American lizards were more closely related to their counterparts in Africa and Asia than to the modern fauna of South America. This suggests both groups of iguanians achieved a worldwide distribution before the final breakup of Pangaea. At some point, non-acrodontans replaced acrodontans and became the only iguanians in the Americas, contrary to what happened on most of the Old World. This discovery also expands the diversity of Cretaceous lizards in South America, which with recent findings, suggests sphenodontians were not the dominant lepidosaurs in that continent as previously hypothesized.

  3. Quantity Discrimination in Trained Lizards (Podarcis sicula

    Directory of Open Access Journals (Sweden)

    Maria Elena Miletto Petrazzini

    2018-03-01

    Full Text Available Quantitative abilities have been reported in many animal species. Two main methods have been extensively used: spontaneous choice tests and training procedures. A recent study showed that ruin lizards are capable of spontaneously discriminating between the surface area of two food items of different size, but failed when food was presented in sets of discrete items differing in number. In the present study, we used a training procedure to further investigate quantitative abilities in ruin lizards. Subjects were presented with two sets of yellow disks differing either in number (Experiment 1 or in area (Experiment 2 and were trained on different discriminations of increasing difficulty (1 vs. 4, 2 vs. 4, and 2 vs. 3. Results showed that lizards were more accurate in discriminating sets of discrete items differing in number than the area of two individual items, in contrast to what had earlier been observed in spontaneous choice tests. Although we cannot exclude other factors that affected the performance of ruin lizards, the poor accuracy here observed in both experiments might reflect a true limit in lizards’ quantitative abilities.

  4. Lizards of Brazilian Amazonia (Reptilia: Squamata)

    NARCIS (Netherlands)

    Avila-Pires, T.C.S.

    1995-01-01

    Eighty-nine species of lizards, six of which polytypic (forming a total of 97 taxa), are presently known from Brazilian Amazonia. This number includes six species and one subspecies described as new to science in this paper: Stenocercus fimbriatus, Lepidoblepharis hoogmoedi, Leposoma osvaldoi, L.

  5. Coupled ears in lizards and crocodilians

    DEFF Research Database (Denmark)

    Carr, Catherine E; Christensen-Dalsgaard, Jakob; Bierman, Hilary

    2016-01-01

    Lizard ears are coupled across the pharynx, and are very directional. In consequence all auditory responses should be directional, without a requirement for computation of sound source location. Crocodilian ears are connected through sinuses, and thus less tightly coupled. Coupling may improve th...... range is reviewed in the light of current theories of sound localization....

  6. Diets Alter the Gut Microbiome of Crocodile Lizards

    Directory of Open Access Journals (Sweden)

    Hai-Ying Jiang

    2017-10-01

    Full Text Available The crocodile lizard is a critically endangered reptile, and serious diseases have been found in this species in recent years, especially in captive lizards. Whether these diseases are caused by changes in the gut microbiota and the effect of captivity on disease remains to be determined. Here, we examined the relationship between the gut microbiota and diet and disease by comparing the fecal microbiota of wild lizards with those of sick and healthy lizards in captivity. The gut microbiota in wild crocodile lizards was consistently dominated by Proteobacteria (∼56.4% and Bacteroidetes (∼19.1%. However, the abundance of Firmicutes (∼2.6% in the intestine of the wild crocodile lizards was distinctly lower than that in other vertebrates. In addition, the wild samples from Guangdong Luokeng Shinisaurus crocodilurus National Nature Reserve also had a high abundance of Deinococcus–Thermus while the wild samples from Guangxi Daguishan Crocodile Lizard National Nature Reserve had a high abundance of Tenericutes. The gut microbial community in loach-fed crocodile lizards was significantly different from the gut microbial community in the earthworm-fed and wild lizards. In addition, significant differences in specific bacteria were detected among groups. Notably, in the gut microbiota, the captive lizards fed earthworms resulted in enrichment of Fusobacterium, and the captive lizards fed loaches had higher abundances of Elizabethkingia, Halomonas, Morganella, and Salmonella, all of which are pathogens or opportunistic pathogens in human or other animals. However, there is no sufficient evidence that the gut microbiota contributes to either disease A or disease B. These results provide a reference for the conservation of endangered crocodile lizards and the first insight into the relationship between disease and the gut microbiota in lizards.

  7. Public attention is focused to concrete protective fence; Konkurito sei bogosaku ni shumoku

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-10

    The installation standards for protective fence was revised last November, and public interest is increased for these standards. Corresponding to this situation, the Cement Association held a revised installation standards explanation meeting, in cooperation with Steel Protective Fence Association and Japan Aluminum Association, in Tokyo for road managers mainly in areas under jurisdiction of Kanto Regional Construction Bureau. By the revised installation standards, concrete protective fence can be treated equal to steel. Traffic safety of drivers and passengers as well as economic effect by long maintenance span can be expected by popularization of concrete protective fence. (translated by NEDO)

  8. Proprioceptive Ability of Fencing and Table Tennis Practioners

    Directory of Open Access Journals (Sweden)

    Bańkosz Ziemowit

    2014-09-01

    Full Text Available Purpose. The aim of the study was to compare the spatial component of proprioceptive ability by reproducing a upper limb movement typical in table tennis and fencing. Methods. The research comprised 41 young males of which 12 were table tennis players, 14 fencers, and 15 not involved in any competitive sports as a control. The experiment was based on assessing the precision of pronation and supination of the forearm at the elbow joint in recreating a set movement range by use of a goniometer. Results and conclusions. The results point to a higher level of proprioceptive ability in fencers and table tennis players than the control group but only in respect to the tasks executed with the dominant limb. This is inferred to be the result from the specific character of both sports (i.e. the intensive use of one limb and the consequent laterality of that limb causing higher sensitivity and proprioception. This may provide a link between swordplay, table tennis, and the level of proprioception. The research methodology used herein may be useful in monitoring fencing training. Although not unequivocally statistically significant, the results indicate the potential for further research in this area.

  9. Fenced and Fragmented: Conservation Value of Managed Metapopulations

    Science.gov (United States)

    Miller, Susan M.; Harper, Cindy K.; Bloomer, Paulette; Hofmeyr, Jennifer; Funston, Paul J.

    2015-01-01

    Population fragmentation is threatening biodiversity worldwide. Species that once roamed vast areas are increasingly being conserved in small, isolated areas. Modern management approaches must adapt to ensure the continued survival and conservation value of these populations. In South Africa, a managed metapopulation approach has been adopted for several large carnivore species, all protected in isolated, relatively small, reserves that are fenced. As far as possible these approaches are based on natural metapopulation structures. In this network, over the past 25 years, African lions (Panthera leo) were reintroduced into 44 fenced reserves with little attention given to maintaining genetic diversity. To examine the situation, we investigated the current genetic provenance and diversity of these lions. We found that overall genetic diversity was similar to that in a large national park, and included a mixture of four different southern African evolutionarily significant units (ESUs). This mixing of ESUs, while not ideal, provides a unique opportunity to study the impact of mixing ESUs over the long term. We propose a strategic managed metapopulation plan to ensure the maintenance of genetic diversity and improve the long-term conservation value of these lions. This managed metapopulation approach could be applied to other species under similar ecological constraints around the globe. PMID:26699333

  10. South Fence Road -- Phase 1 field operations summary

    Energy Technology Data Exchange (ETDEWEB)

    McCord, J.P. [INTERA, Inc., Albuquerque, NM (United States); Neel, D. [GRAM, Inc., Albuquerque, NM (United States)

    1996-03-01

    The South Fence Road (SFR) project is part of the Sandia National Laboratories, New Mexico (SNL/NM) Site-Wide Hydrogeologic Characterization (SWHC) task. The SWHC task has as its objective the reduction of uncertainty about the rate and direction of groundwater flow in the SNL/NM/Kirtland Air Force Base (KAFB) area. The SFR project area is located along the southern boundary of SNL/KAFB. This project area was selected to provide site-specific information related to geology and groundwater hydrology within the Hubbell Spring/Tijeras/Sandia fault complex. Specific objectives included determining the depth to the Santa Fe Group/bedrock contact, the depth to the water table, and the hydrogeologic complexities related to faulting. This report is a basic data report from the first phase of field operations associated with the drilling, logging, completion, and development of South Fence Road Wells SFR-1D and SFR-1S, SFR-2, SFR-3D and SFR-3S, and SFR-4. These test/monitoring wells were installed as part of Sandia National Laboratories, New Mexico, Environmental Restoration Project.

  11. South Fence Road -- Phase 1 field operations summary

    International Nuclear Information System (INIS)

    McCord, J.P.; Neel, D.

    1996-03-01

    The South Fence Road (SFR) project is part of the Sandia National Laboratories, New Mexico (SNL/NM) Site-Wide Hydrogeologic Characterization (SWHC) task. The SWHC task has as its objective the reduction of uncertainty about the rate and direction of groundwater flow in the SNL/NM/Kirtland Air Force Base (KAFB) area. The SFR project area is located along the southern boundary of SNL/KAFB. This project area was selected to provide site-specific information related to geology and groundwater hydrology within the Hubbell Spring/Tijeras/Sandia fault complex. Specific objectives included determining the depth to the Santa Fe Group/bedrock contact, the depth to the water table, and the hydrogeologic complexities related to faulting. This report is a basic data report from the first phase of field operations associated with the drilling, logging, completion, and development of South Fence Road Wells SFR-1D and SFR-1S, SFR-2, SFR-3D and SFR-3S, and SFR-4. These test/monitoring wells were installed as part of Sandia National Laboratories, New Mexico, Environmental Restoration Project

  12. Habitat degradation may affect niche segregation patterns in lizards

    Science.gov (United States)

    Pelegrin, N.; Chani, J. M.; Echevarria, A. L.; Bucher, E. H.

    2013-08-01

    Lizards partition resources in three main niche dimensions: time, space and food. Activity time and microhabitat use are strongly influenced by thermal environment, and may differ between species according to thermal requirements and tolerance. As thermal characteristics are influenced by habitat structure, microhabitat use and activity of lizards can change in disturbed habitats. We compared activity and microhabitat use of two abundant lizard species of the Semi-arid Chaco of Argentina between a restored and a highly degraded Chaco forest, to determine how habitat degradation affects lizard segregation in time and space, hypothesizing that as activity and microhabitat use of lizards are related to habitat structure, activity and microhabitat use of individual species can be altered in degraded habitats, thus changing segregation patterns between them. Activity changed from an overlapped pattern in a restored forest to a segregated pattern in a degraded forest. A similar trend was observed for microhabitat use, although to a less extent. No correlation was found between air temperature and lizard activity, but lizard activity varied along the day and among sites. Contrary to what was believed, activity patterns of neotropical diurnal lizards are not fixed, but affected by multiple factors related to habitat structure and possibly to interspecific interactions. Changes in activity patterns and microhabitat use in degraded forests may have important implications when analyzing the effects of climate change on lizard species, due to synergistic effects.

  13. Higher Stakes--The Hidden Risks of School Security Fences for Children's Learning Environments

    Science.gov (United States)

    Rooney, Tonya

    2015-01-01

    In a move away from the open or low-fenced grounds that have traditionally been a feature of Australian school design, the last decade has seen a growth in the installation of high-security fences around schools. These structures, far from being passive and neutral, act to redefine the possibilities for movement and connectivity in the local…

  14. Diagnostic Imaging in Snakes and Lizards

    OpenAIRE

    Banzato , Tommaso

    2013-01-01

    The increasing popularity of snakes and lizards as pets has led to an increasing demand of specialised veterinary duties in these animals. Diagnostic imaging is often a fundamental step of the clinical investigation. The interpretation of diagnostic images is complex and requires a broad knowledge of anatomy, physiology and pathology of the species object of the clinical investigation. Moreover, in order to achieve a correct diagnosis, the comparison between normal and abnormal diagnostic im...

  15. [Application of electronic fence technology based on GIS in Oncomelania hupensis snail monitoring].

    Science.gov (United States)

    Zhi-Hua, Chen; Yi-Sheng, Zhu; Zhi-Qiang, Xue; Xue-Bing, Li; Yi-Min, Ding; Li-Jun, Bi; Kai-Min, Gao; You, Zhang

    2017-07-27

    To study the application of Geographic Information System (GIS) electronic fence technique in Oncomelania hupensis snail monitoring. The electronic fence was set around the history and existing snail environments in the electronic map, the information about snail monitoring and controlling was linked to the electronic fence, and the snail monitoring information system was established on these bases. The monitoring information was input through the computer and smart phone. The electronic fence around the history and existing snail environments was set in the electronic map (Baidu map), and the snail monitoring information system and smart phone APP were established. The monitoring information was input and upload real-time, and the snail monitoring information was demonstrated in real time on Baidu map. By using the electronic fence technology based on GIS, the unique "environment electronic archives" for each snail monitoring environment can be established in the electronic map, and real-time, dynamic monitoring and visual management can be realized.

  16. Fencing data transfers in a parallel active messaging interface of a parallel computer

    Science.gov (United States)

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-06-02

    Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task; the compute nodes coupled for data communications through the PAMI and through data communications resources including at least one segment of shared random access memory; including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers through a segment of shared memory; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

  17. Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

    Science.gov (United States)

    Blocksome, Michael A.; Mamidala, Amith R.

    2013-09-03

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  18. Eocene lizard from Germany reveals amphisbaenian origins.

    Science.gov (United States)

    Müller, Johannes; Hipsley, Christy A; Head, Jason J; Kardjilov, Nikolay; Hilger, André; Wuttke, Michael; Reisz, Robert R

    2011-05-19

    Amphisbaenia is a speciose clade of fossorial lizards characterized by a snake-like body and a strongly reinforced skull adapted for head-first burrowing. The evolutionary origins of amphisbaenians are controversial, with molecular data uniting them with lacertids, a clade of Old World terrestrial lizards, whereas morphology supports a grouping with snakes and other limbless squamates. Reports of fossil stem amphisbaenians have been falsified, and no fossils have previously tested these competing phylogenetic hypotheses or shed light on ancestral amphisbaenian ecology. Here we report the discovery of a new lacertid-like lizard from the Eocene Messel locality of Germany that provides the first morphological evidence for lacertid-amphisbaenian monophyly on the basis of a reinforced, akinetic skull roof and braincase, supporting the view that body elongation and limblessness in amphisbaenians and snakes evolved independently. Morphometric analysis of body shape and ecology in squamates indicates that the postcranial anatomy of the new taxon is most consistent with opportunistically burrowing habits, which in combination with cranial reinforcement indicates that head-first burrowing evolved before body elongation and may have been a crucial first step in the evolution of amphisbaenian fossoriality.

  19. A fence with several safety wires with alarm equipment

    International Nuclear Information System (INIS)

    Osterburg, G.

    1977-01-01

    The patent claim concerns a safety arrangement for objects in the open against unauthorised interference. A fence provided with several safety wires is used for this purpose. Each wire has a piezo-electric transmitter at one end, and has a piezo-electric receiver at the other end, which converts the mechanical vibrations into electrical signals. The piezo-electric receiver is connected via an amplifier to the piezo-electric transmitter of the next wire, which initiates the latter to produce mechanical vibrations and so on, until the transmitter of the first wire is reached again, so that a closed feed-back loop is formed. An electronic evaluation circuit is connected between one of the amplfiers and the subsequent transmitter, which on loss of vibration due to touching, hold. (ORU) [de

  20. Mitigating Reptile Road Mortality: Fence Failures Compromise Ecopassage Effectiveness

    Science.gov (United States)

    Baxter-Gilbert, James H.; Riley, Julia L.; Lesbarrères, David; Litzgus, Jacqueline D.

    2015-01-01

    Roadways pose serious threats to animal populations. The installation of roadway mitigation measures is becoming increasingly common, yet studies that rigorously evaluate the effectiveness of these conservation tools remain rare. A highway expansion project in Ontario, Canada included exclusion fencing and ecopassages as mitigation measures designed to offset detrimental effects to one of the most imperial groups of vertebrates, reptiles. Taking a multispecies approach, we used a Before-After-Control-Impact study design to compare reptile abundance on the highway before and after mitigation at an Impact site and a Control site from 1 May to 31 August in 2012 and 2013. During this time, radio telemetry, wildlife cameras, and an automated PIT-tag reading system were used to monitor reptile movements and use of ecopassages. Additionally, a willingness to utilize experiment was conducted to quantify turtle behavioral responses to ecopassages. We found no difference in abundance of turtles on the road between the un-mitigated and mitigated highways, and an increase in the percentage of both snakes and turtles detected dead on the road post-mitigation, suggesting that the fencing was not effective. Although ecopassages were used by reptiles, the number of crossings through ecopassages was lower than road-surface crossings. Furthermore, turtle willingness to use ecopassages was lower than that reported in previous arena studies, suggesting that effectiveness of ecopassages may be compromised when alternative crossing options are available (e.g., through holes in exclusion structures). Our rigorous evaluation of reptile roadway mitigation demonstrated that when exclusion structures fail, the effectiveness of population connectivity structures is compromised. Our project emphasizes the need to design mitigation measures with the biology and behavior of the target species in mind, to implement mitigation designs in a rigorous fashion, and quantitatively evaluate road

  1. Mitigating reptile road mortality: fence failures compromise ecopassage effectiveness.

    Directory of Open Access Journals (Sweden)

    James H Baxter-Gilbert

    Full Text Available Roadways pose serious threats to animal populations. The installation of roadway mitigation measures is becoming increasingly common, yet studies that rigorously evaluate the effectiveness of these conservation tools remain rare. A highway expansion project in Ontario, Canada included exclusion fencing and ecopassages as mitigation measures designed to offset detrimental effects to one of the most imperial groups of vertebrates, reptiles. Taking a multispecies approach, we used a Before-After-Control-Impact study design to compare reptile abundance on the highway before and after mitigation at an Impact site and a Control site from 1 May to 31 August in 2012 and 2013. During this time, radio telemetry, wildlife cameras, and an automated PIT-tag reading system were used to monitor reptile movements and use of ecopassages. Additionally, a willingness to utilize experiment was conducted to quantify turtle behavioral responses to ecopassages. We found no difference in abundance of turtles on the road between the un-mitigated and mitigated highways, and an increase in the percentage of both snakes and turtles detected dead on the road post-mitigation, suggesting that the fencing was not effective. Although ecopassages were used by reptiles, the number of crossings through ecopassages was lower than road-surface crossings. Furthermore, turtle willingness to use ecopassages was lower than that reported in previous arena studies, suggesting that effectiveness of ecopassages may be compromised when alternative crossing options are available (e.g., through holes in exclusion structures. Our rigorous evaluation of reptile roadway mitigation demonstrated that when exclusion structures fail, the effectiveness of population connectivity structures is compromised. Our project emphasizes the need to design mitigation measures with the biology and behavior of the target species in mind, to implement mitigation designs in a rigorous fashion, and quantitatively

  2. Agama lizard: A potential biomarker of environmental heavy metal ...

    African Journals Online (AJOL)

    In this study, the suitability of Agama lizard as a biomarker in assessing environmental pollution levels of arsenium (As), barium (Ba), cadmium (Cd), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) was investigated. Samples of top soil and agama lizards were taken from five sites within a university community in ...

  3. Observations on sexual dimorphism and social structure in the lizard ...

    African Journals Online (AJOL)

    Angolosaurus skoogi is a large, herbivorous lizard of the northern Namib dune sea. Adults are sexually dimorphic in body size and colouration and these differences may be related to social organization. Whether the observed dimorphism is a result of the mating system, as is the case with several other herbivorous lizards, ...

  4. Tech-Savvy Beef Cattle? How Heifers Respond to Moving Virtual Fence Lines

    Directory of Open Access Journals (Sweden)

    Dana L.M. Campbell

    2017-09-01

    Full Text Available Global Positioning System (GPS-based virtual fences offer the potential to improve the management of grazing animals. Prototype collar devices utilising patented virtual fencing algorithms were placed on six Angus heifers in a 6.15 hectare paddock. After a “no fence” period, sequential, shifting virtual fences restricted the animals to 40%, 60%, and 80% of the paddock area widthways and 50% lengthways across 22 days. Audio cues signaled the virtual boundary, and were paired with electrical stimuli if the animals continued forward into the boundary. Within approximately 48 h, the cattle learned the 40% fence and were henceforth restricted to the subsequent inclusion zones a minimum of 96.70% (±standard error 0.01% of the time. Over time, the animals increasingly stayed within the inclusion zones using audio cues alone, and on average, approached the new fence within 4.25 h. The animals were thus attentive to the audio cue, not the fence location. The time spent standing and lying and the number of steps were similar between inclusion zones (all p ≥ 0.42. More lying bouts occurred at the 80% and lengthways inclusion zones relative to “no fence” (p = 0.04. Further research should test different cattle groups in variable paddock settings and measure physiological welfare responses to the virtual fencing stimuli.

  5. Conceptual principles of fencing development in children’s sports schools in Ukraine

    Directory of Open Access Journals (Sweden)

    O.V. Driukov

    2015-12-01

    Full Text Available Purpose: to work out conceptual principles for successful and dynamic development of fencing in children’s sports schools in Ukraine. Material: the researches were conducted on material of children’s sports school Dynamo in Kiev. In this work we used SWOT analysis - method of strategic planning, which implies determination of external and internal factors of organization and their dividing into four categories: strengths (strong sides, weaknesses (weak sides, opportunities and threats. For determination of experts’ opinion concordance in SWOT analysis we used concordance coefficient. Results: we worked out conception of fencing development in children’s sports schools in Ukraine in modern conditions. The specificity of this conception implies determination of strategic approaches to further fencing progressing in children’s sports schools in Ukraine. The conception can serve as bench mark for development and realization of program documents in sphere of fencing progressing or its different branches. Conclusions: we have worked out conception of fencing progressing in children’s sports schools in Ukraine, which is based on achievements and traditions of fencing in Ukraine and in the world. Its development is based on systemic analysis of internal and external factors, which influence on development of fencing in sports schools and on choice of its progressing strategy in new social economical conditions.

  6. Border Security Fencing and Wildlife: The End of the Transboundary Paradigm in Eurasia?

    Science.gov (United States)

    Linnell, John D. C.; Trouwborst, Arie; Boitani, Luigi; Kaczensky, Petra; Kusak, Josip; Skrbinsek, Tomaz; Buuveibaatar, Bayarbaatar; Bischof, Richard; Breitenmoser, Urs

    2016-01-01

    The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures. PMID:27331878

  7. Border Security Fencing and Wildlife: The End of the Transboundary Paradigm in Eurasia?

    Science.gov (United States)

    Linnell, John D C; Trouwborst, Arie; Boitani, Luigi; Kaczensky, Petra; Huber, Djuro; Reljic, Slaven; Kusak, Josip; Majic, Aleksandra; Skrbinsek, Tomaz; Potocnik, Hubert; Hayward, Matt W; Milner-Gulland, E J; Buuveibaatar, Bayarbaatar; Olson, Kirk A; Badamjav, Lkhagvasuren; Bischof, Richard; Zuther, Steffen; Breitenmoser, Urs

    2016-06-01

    The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures.

  8. Distribution pattern and number of ticks on lizards.

    Science.gov (United States)

    Dudek, Krzysztof; Skórka, Piotr; Sajkowska, Zofia Anna; Ekner-Grzyb, Anna; Dudek, Monika; Tryjanowski, Piotr

    2016-02-01

    The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae. Copyright © 2015

  9. Designing, developing and implementing a living snow fence program for New York state.

    Science.gov (United States)

    2015-07-01

    Living snow fences (LSF) are a form of passive snow control designed to mitigate blowing and drifting snow problems : on roadways. Blowing and drifting snow can increase the cost of highway maintenance and create hazardous driving : conditions when s...

  10. Beehive fences as a multidimensional conflict-mitigation tool for farmers coexisting with elephants.

    Science.gov (United States)

    King, Lucy E; Lala, Fredrick; Nzumu, Hesron; Mwambingu, Emmanuel; Douglas-Hamilton, Iain

    2017-08-01

    Increasing habitat fragmentation and human population growth in Africa has resulted in an escalation in human-elephant conflict between small-scale farmers and free-ranging African elephants (Loxodonta Africana). In 2012 Kenya Wildlife Service (KWS) implemented the national 10-year Conservation and Management Strategy for the Elephant in Kenya, which includes an action aimed at testing whether beehive fences can be used to mitigate human-elephant conflict. From 2012 to 2015, we field-tested the efficacy of beehive fences to protect 10 0.4-ha farms next to Tsavo East National Park from elephants. We hung a series of beehives every 10 m around the boundary of each farm plot. The hives were linked with strong wire. After an initial pilot test with 2 farms, the remaining 8 of 10 beehive fences also contained 2-dimensional dummy hives between real beehives to help reduce the cost of the fence. Each trial plot had a neighboring control plot of the same size within the same farm. Of the 131 beehives deployed 88% were occupied at least once during the 3.5-year trial. Two hundred and fifty-three elephants, predominantly 20-45 years old entered the community farming area, typically during the crop- ripening season. Eighty percent of the elephants that approached the trial farms were kept out of the areas protected by the beehive fences, and elephants that broke a fence were in smaller than average groups. Beehive fences not only kept large groups of elephants from invading the farmland plots but the farmers also benefited socially and financially from the sale of 228 kg of elephant-friendly honey. As news of the success of the trial spread, a further 12 farmers requested to join the project, bringing the number of beehive fence protected farms to 22 and beehives to 297. This demonstrates positive adoption of beehive fences as a community mitigation tool. Understanding the response of elephants to the beehive fences, the seasonality of crop raiding and fence breaking, and the

  11. Intelligent Machine Vision for Automated Fence Intruder Detection Using Self-organizing Map

    OpenAIRE

    Veldin A. Talorete Jr.; Sherwin A Guirnaldo

    2017-01-01

    This paper presents an intelligent machine vision for automated fence intruder detection. A series of still captured images that contain fence events using Internet Protocol cameras was used as input data to the system. Two classifiers were used; the first is to classify human posture and the second one will classify intruder location. The system classifiers were implemented using Self-Organizing Map after the implementation of several image segmentation processes. The human posture classifie...

  12. FenceBook a Geofencing based Advertisements Application Using Android

    Directory of Open Access Journals (Sweden)

    Owais Qayum

    2016-10-01

    Full Text Available Geo-fencing (geofencing is a great feature in a software program that uses Global Positioning System (GPS or radio frequency identification (RFID to define the geographical boundaries feature. Actually geofence is a virtual barrier. Geofencing is an innovative technology, an online marketplace for proactive contextual services that allows users to easily find interesting services, can easily subscribe to it and to allow providers offer their services for a variety of applications such as electronic toll collection, contextual advertising or tourist information systems, even without additional infrastructure. The main objective of this research was to understand how the use of spatial data can improve advertising performance for customers. Tracking systems and monitoring, based on global navigation services by satellite, and include geofencing function, could also contribute to the exact location of an institution or company and increase sales and business perspective efficiently. Instead of large billboards they can now advertise on smartphones which is economically and accurately tested. Therefore, we have developed a concept for a market that offers geofence, which can be applied by all and increase the use and integration of proactive services based on location in everyday life.

  13. The Failure of the American Dream in August Wilson's Fences

    Directory of Open Access Journals (Sweden)

    Peyman Amanolahi Baharvand

    2017-12-01

    Full Text Available This paper traces the impossibility of the fulfillment of the American dream for AfricanAmericans in August Wilson‟s Fences. It examines why Troy Maxon, as the protagonist of the play, is not able to fulfill his dreams of freedom, and economic achievements in an environment of oppression where he finds himself surrounded by hostile whites who hinder his development. It indicates that the racial discrimination, manifested in various forms including racial segregation prevalent in the white-dominated American society, impedes Troy‟s progress. A large number of African-Americans migrated from southern states to the north in 1920s and 1930s in order to find jobs in industrial northern states. They had been told that the United States was the promised land of equal chances wherein everyone regardless of race and gender was able to progress from rags to riches. They left the South, in which racism was still pervasive despite the abolition of slavery, and moved to the North for the fulfillment of the dreams they had been promised. The advocates of the American Dream claimed that hard diligence and intelligence could lead a man to material prosperity. Nevertheless, this paper demonstrates that since African-Americans are considered to be „„others‟‟ in the white dominated society, financial progress and other aspects of the American Dream remain impossible dreams for them.

  14. Developing an Ethically Acceptable Virtual Fencing System for Sheep

    Directory of Open Access Journals (Sweden)

    Danila Marini

    2018-02-01

    Full Text Available To ensure animal welfare isn’t compromised when using virtual fencing, animals must be able to associate a benign conditioned stimulus with an aversive stimulus. This study used an associative learning test to train 30, four-year-old, Merino x Suffolk ewes, to associate an audio cue with an electric stimulus. Collars manually controlled by a GPS hand-held unit were used to deliver the audio and electric stimuli cues. For the associative learning, when sheep approached an attractant at a distance of three m from the trough, an audio cue was applied for one s. If the sheep stopped or changed direction, the audio cue ceased immediately and no electrical stimulus was applied. If the sheep did not respond to the audio cue it was followed by a low-level electrical stimulus. Approaches to the attractant significantly decreased from day one to day two. It took a mean of three pairings of the audio cue and electrical stimulus for a change in behaviour to occur, after which sheep that approached the attractant had a 52% probability of avoiding the electrical stimulus and responding to the audio cue alone. Further research is required to determine whether sheep can be trained to associate an audio cue with a negative stimulus for use in group grazing situations.

  15. Phylogeny of Neotropical Cercosaura (Squamata: Gymnophthalmidae) lizards.

    Science.gov (United States)

    Torres-Carvajal, Omar; Lobos, Simón E; Venegas, Pablo J

    2015-12-01

    Among Neotropical lizards, the geographically widespread gymnophthalmid Cercosaura as currently defined includes lowland and highland taxa from Panama to Argentina, with some species occurring in the northern Andes. In this study we analyze three mitochondrial (12S, 16S, ND4) and one nuclear (c-mos) gene using Bayesian methods to clarify the phylogenetic relationships among most species of Cercosaura based on a well-supported phylogenetic hypothesis that also includes a large sample of other taxa within Cercosaurini. The phylogenetic tree obtained in this paper shows that Cercosaura as currently defined is not monophyletic. Two species from the northern Andes (C. dicra and C. vertebralis) are nested within Pholidobolus, which has been formerly recognized as a major radiation along the Andes of Ecuador and Colombia. Therefore, Cercosaura has probably not diversified in the northern Andes, although the phylogenetic position of C. hypnoides from the Andes of Colombia remains unknown. Tree topology and genetic distances support both recognition of C. ocellata bassleri as a distinct species, C. bassleri, and recognition of C. argula and C. oshaughnessyi as two different species. In the interest of promoting clarity and precision regarding the names of clades of gymnophthalmid lizards, we propose a phylogenetic definition of Cercosaura. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. How lizards fly: A novel type of wing in animals.

    Science.gov (United States)

    Dehling, J Maximilian

    2017-01-01

    Flying lizards of the genus Draco are renowned for their gliding ability, using an aerofoil formed by winglike patagial membranes and supported by elongated thoracic ribs. It remains unknown, however, how these lizards manoeuvre during flight. Here, I present the results of a study on the aerial behaviour of Dussumier's Flying Lizard (Draco dussumieri) and show that Draco attaches the forelimbs to the leading edge of the patagium while airborne, forming a hitherto unknown type of composite wing. The attachment of the forelimbs to the patagium suggests that that aerofoil is controlled through movements of the forelimbs. One major advantage for the lizards is that the forelimbs retain their complete range of movement and functionality for climbing and running when not used as a part of the wing. These findings not only shed a new light on the flight of Draco but also have implications for the interpretation of gliding performance in fossil species.

  17. Status of the Island Night Lizard and Two Non-Native Lizards on Outlying Landing Field San Nicolas Island, California

    Science.gov (United States)

    Fellers, Gary M.; Drost, Charles A.; Murphey, Thomas G.

    2008-01-01

    More than 900 individually marked island night lizards (Xantusia riversiana) were captured on San Nicolas Island, California, between 1984 and 2007 as part of an ongoing study to monitor the status of this threatened species. Our data suggest that at least a few lizards are probably more than 20 years old, and one lizard would be 31.5 years old if it grew at an average rate for the population. Ages of 20 and 30 years seem reasonable given the remarkably slow growth during capture intervals of more than a decade for five of the lizards which we estimated to be 20 or more years old. Like other lizards, island night lizard growth rates vary by size, with larger lizards growing more slowly. In general, growth rates were somewhat greater on San Nicolas Island (compared with Santa Barbara Island), and this increase was sustained through all of the intermediate size classes. The higher growth rate may account for the somewhat larger lizards present on San Nicolas Island, although we cannot discount the possibility that night lizards on San Nicolas are merely living longer. The high percentage of small lizards in the Eucalyptus habitat might seem to reflect a healthy population in that habitat, but the high proportion of small lizards appears to be caused by good reproduction in the 1900s and substantially poorer reproduction in subsequent years. The Eucalyptus habitat has dried quite a bit in recent years. Night lizards in the Haplopappus/Grassland habitat have shown an increase in the proportion of larger lizards since 2000. There has also been an increase in the proportion of large lizards in the Rock Cobble habitat at Redeye Beach. However, there are has been some change in habitat with more elephant seals occupying the same area just above the high tide as do the night lizards. Southern alligator lizards and side-blotched lizards are both non-native on San Nicolas Island. Neither lizard causes obvious harm to island night lizards, and management time and effort should

  18. Dietary pathways through lizards of the Alligator Rivers Region

    International Nuclear Information System (INIS)

    James, C.D.; Morton, S.R.; Braithwaite, R.W.; Wombey, J.C.

    1984-07-01

    A broad survey of the diets of 46 species of terrestrial and arboreal lizards from the families Gekkonidae, Pygopodidae, Agamidae and Scincidae was carried out in the Alligator Rivers Region, and the diets of three of the species were examined in detail by monthly sampling near the Ranger uranium mine. The study shows that, in the event of contamination of the waterbodies, only two species of lizards face any risk of contamination through their food

  19. A New Eocene Casquehead Lizard (Reptilia, Corytophanidae from North America.

    Directory of Open Access Journals (Sweden)

    Jack L Conrad

    Full Text Available A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma. Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America.

  20. Mate familiarity and social learning in a monogamous lizard.

    Science.gov (United States)

    Munch, Kirke L; Noble, Daniel W A; Wapstra, Erik; While, Geoffrey M

    2018-05-08

    Social learning is thought to be advantageous as it allows an animal to gather information quickly without engaging in costly trial-and-error learning. However, animals should be selective about when and whom they learn from. Familiarity is predicted to positively influence an animal's reliance on social learning; yet, few studies have empirically tested this theory. We used a lizard (Liopholis whitii) that forms long-term monogamous pair bonds to examine the effects of partner familiarity on social learning in two novel foraging tasks, an association and a reversal task. We allowed female lizards to observe trained conspecifics that were either familiar (social mate) or unfamiliar execute these tasks and compared these two groups with control females that did not receive social information. Lizards preferentially relied on trial-and-error learning in the association task. In the reversal task, lizards that were demonstrated by familiar partners learnt in fewer trials compared to control lizards and made more correct choices. Our results provide some evidence for context-dependent learning with lizards differentiating between when they utilize social learning, and, to a limited degree, whom they learnt from. Understanding the role of the social context in which learning occurs provides important insights into the benefits of social learning and sociality more generally.

  1. Life-History Patterns of Lizards of the World.

    Science.gov (United States)

    Mesquita, Daniel O; Costa, Gabriel C; Colli, Guarino R; Costa, Taís B; Shepard, Donald B; Vitt, Laurie J; Pianka, Eric R

    2016-06-01

    Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales.

  2. Ranavirus infections associated with skin lesions in lizards.

    Science.gov (United States)

    Stöhr, Anke C; Blahak, Silvia; Heckers, Kim O; Wiechert, Jutta; Behncke, Helge; Mathes, Karina; Günther, Pascale; Zwart, Peer; Ball, Inna; Rüschoff, Birgit; Marschang, Rachel E

    2013-09-27

    Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards.

  3. Earliest example of a giant monitor lizard (Varanus, Varanidae, Squamata).

    Science.gov (United States)

    Conrad, Jack L; Balcarcel, Ana M; Mehling, Carl M

    2012-01-01

    Varanidae is a clade of tiny (600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors.

  4. Effectiveness of Wildlife Underpasses and Fencing to Reduce Wildlife–Vehicle Collisions

    Science.gov (United States)

    ,; McCollister, Matthew F.

    2010-01-01

    Transportation planners are increasingly incorporating roadway design features to mitigate impacts of highways on wildlife and to increase driver safety. We used camera and track surveys to evaluate wildlife use before and after construction of 3 wildlife underpasses and associated fencing on a new section of United States Highway 64 in Washington County, North Carolina, USA. We recorded 242 occasions of white-tailed deer (Odocoileus virginianus) use of underpass areas before highway construction began. Following completion of the highway, we collected 2,433 photographs of 9 species with deer representing 93% of all crossings. Adjusting for differences in number of monitoring days, white-tailed deer use of underpass areas averaged 6.7 times greater after the new highway and underpasses were completed. We recorded 3,614 wildlife crossings of ≥20 species based on track counts, representing most medium and large mammals known to occur in the area and several reptiles and birds. After completion of the highway, we documented wildlife mortality due to vehicle collisions during a 13-month period and recorded 128 incidences representing ≥24 species. Within fenced highway segments, mortalities were lowest near underpasses and increased with distance from the underpasses. However, we also documented more mortalities in fenced areas compared with unfenced areas. With greater distance from an underpass, animals with smaller home ranges seemed less likely to reach the underpass and instead attempted to climb over or crawl under fencing. Based on collision reports from adjacent highway sections, the new section of United States Highway 64 experienced approximately 58% fewer wildlife mortalities (primarily white-tailed deer), suggesting underpasses and fencing reduced the number of deer–vehicle collisions. Continuous fencing between underpasses may further reduce the number of vehicle collisions for deer but additional design features (e.g., buried fencing) should be

  5. [A comparative study on soil respiration between grazing and fenced typical Leymus chinensis steppe, Inner Mongolia].

    Science.gov (United States)

    Jia, Bingrui; Zhou, Guangsheng; Wang, Fengyu; Wang, Yuhui

    2004-09-01

    With enclosed chamber Method, this paper studied the soil respiration in grazing and fenced typical Leymus chinensis steppes, Inner Mongolia, and its relationships with environmental factors. The results showed that the daily pattern of soil respiration could be expressed as a one-humped curve, and the highest values appeared at 13:00-15:00 in the fenced and grazing plots. The diurnal dynamics of soil respiration mainly depended on the surface temperature at the fenced plots and the soil temperature at 5 cm depth at the grazing plots. In June and July, the average soil respiration rate was 2.7 times greater at the fenced plots than that at the grazing plots, while the difference was not distinct in August and September, which was similar with the change of the belowground biomass. The reason was probably that the plant was influenced differently in different phenological phases by grazing and the change of environmental factors. It showed that human activity may not result in the increase of soil respiration rate. The seasonal dynamics of soil respiration was closely correlated with soil water content at the 0-10 cm depth at the fenced and grazing sites, and the maximum R2 was 0.853 and 0.741, respectively. The difference was that the correlation of soil respiration seasonal dynamics with soil water content was larger at the fenced plots than at the grazing plots. The correlations of soil respiration diurnal and seasonal dynamics with temperature and soil water content at lower profiles were larger than those at deeper profiles at the fenced and grazing sites.

  6. "Sexual" behavior in parthenogenetic lizards (Cnemidophorus).

    Science.gov (United States)

    Crews, D; Fitzgerald, K T

    1980-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Basic data on the behavior of parthenogens are lacking, however. We have discovered, from observations of captive Cnemidophorus uniparens, C. velox, and C. tesselatus, behavior patterns remarkably similar to the courtship and copulatory behavior of closely related sexual species. Briefly, in separately housed pairs, one lizard was repeatedly seen to mount and ride its cagemate and appose the cloacal regions. Dissection or palpation revealed that, in each instance, the courted animal was reproductively active, having ovaries containing large, preovulatory follicles, while the courting animal was either reproductively inactive or postovulatory, having ovaries containing only small, undeveloped follicles. These observations are significant for the questions they raise. For example, is this behavior a nonfunctional vestige of the species' ancestry, or is this behavior necessary for successful reproduction in the species (e.g., by priming reproductive neuroendocrine mechanisms as has been demonstrated in sexual species)?

  7. Influence of Students’ Mental and Physical Performance on Development of Technical and Tactical Skills in Fencing

    Directory of Open Access Journals (Sweden)

    І. В. Кривенцова

    2016-04-01

    Full Text Available Study objective: to reveal the relations between the indicators of physical and mental performance and the development of technical and tactical skills in fencers, to determine the significant criteria and tests for selecting students for health-improving and sports fencing groups. Methods: study and analysis of literature; pedagogical observations; physiological methods (physical performance by the Harvard step test with HSTI (Harvard step test Index calculation, mental performance by the correction tables, special exercises to assess fencers’ technical and tactical skills; statistical methods. The reference group students (9 female fencers had five workouts a week, the students (13 female students of test group 1 (TG1 had 2 hours of physical training per week, the TG2 and TG3  (8 and 10 female students respectively had 4 hours of fencing workouts per week. The TG2 had 4 months of fencing experience, and TG3 had one year and 4 months thereof. Results. The reciprocal effects of the performance indicators and the correlation between the indicators of technical and tactical skills of the student fencers allowed to establish the informative value of individual indicators for quality selection of students for the fencing group. The Harvard step test index and the standardized number of errors of the correction test can serve as the prognostic criteria for developing technical and tactical skills in student fencing.

  8. AMPLITUDE, TRAJECTORY AND AFFERENT PARAMETERS ANALYSIS OF THE JUMP OVER A VERTICAL FENCE IN SPORT HORSES

    Directory of Open Access Journals (Sweden)

    FLAVIA BOCHIS

    2008-10-01

    Full Text Available There are a lot of obstacles type used in jumping competitions. Normally, for every kind of fence, there is a different type of approaching and cross over. The most used obstacles are the vertical fence and the oxer fence. For crossing over the vertical, which is a high fence, the horse must jump only in report to the height of the bar. In the oxer case, which is a large obstacle, the horse must jump related to the height and the largeness of it indeed. In the present study we obtained for the vertical fence, situated at five different levels. The purpose was to measure four parameters for every jump: the taking-off distance, the landing distance, and the distance between bar and legs for the front limbs and for the hind limbs. Based on these, were calculated in report to the type of the show arena the amplitude of the jumps, was assign the trajectory curve and placed the balance point.

  9. Topological optimization of opening fence brackets on ring-stiffened cylindrical shell

    Directory of Open Access Journals (Sweden)

    SONG Xiaofei

    2018-02-01

    Full Text Available [Objectives] Stress concentration is prone to take place at connections between the opening fence and ring ribs of a ring-stiffened cylindrical shell under external pressure. [Methods] In this paper, a topological optimization method for the brackets that connect the fence to the ring ribs is proposed in order to effectively reduce the local high stress in the brackets. The sub-model technique is used to analyze the stress of the connecting brackets. In the design, the connection brackets are used as design variables and the stress of the shell, fence and ribs are used as constraints. The maximum stress of the bracket is minimized as the objective function. The topology optimization results are engineered to obtain the final form of the brackets. [Results] The calculation results show that brackets of which the panel is partially widened can effectively reduce the stress concentration position of the opening fence transverse offset if the side of the bracket away from the longitudinal section is longer; the opening fence is offset relative to the brackets, and the symmetrical design of the brackets is feasible. [Conclusions] This research provides a reference for similar structural design.

  10. Tibial shock measured during the fencing lunge: the influence of footwear.

    Science.gov (United States)

    Sinclair, Jonathan; Bottoms, Lindsay; Taylor, Katrina; Greenhalgh, Andrew

    2010-06-01

    Fencing is a high-intensity sport involving dynamic movements such as the lunge exposing the musculoskeletal system to high impact forces, which emphasises the importance of the shock attenuating properties of footwear as a factor in the prevention of injury. The aim of this study was to investigate the magnitudes of the transient axial impact shock experienced at the tibia between traditional fencing shoes and standard athletic footwear during the impact phase of the fencing lunge. Peak tibial shock was measured in 19 male fencers in 4 different footwear conditions using an accelerometer placed on the distal aspect of the tibia. The standard footwear (11.08 g and 8.75 g for squash and running shoe, respectively) resulted in significant (p Adidas and Hi-Tec shoe, respectively). No significant differences were found between the running and squash shoes (p = 0.09) or between the fencing shoes (p = 0.48). The documented reduction in impact shock found suggests that running or squash specific footwear may reduce overuse injury occurrence, indicating that there is justification for a re-design of fencing shoes.

  11. Hotter nests produce hatchling lizards with lower thermal tolerance.

    Science.gov (United States)

    Dayananda, Buddhi; Murray, Brad R; Webb, Jonathan K

    2017-06-15

    In many regions, the frequency and duration of summer heatwaves is predicted to increase in future. Hotter summers could result in higher temperatures inside lizard nests, potentially exposing embryos to thermally stressful conditions during development. Potentially, developmentally plastic shifts in thermal tolerance could allow lizards to adapt to climate warming. To determine how higher nest temperatures affect the thermal tolerance of hatchling geckos, we incubated eggs of the rock-dwelling velvet gecko, Amalosia lesueurii , at two fluctuating temperature regimes to mimic current nest temperatures (mean 23.2°C, range 10-33°C, 'cold') and future nest temperatures (mean 27.0°C, range 14-37°C, 'hot'). Hatchlings from the hot incubation group hatched 27 days earlier and had a lower critical thermal maximum (CT max 38.7°C) and a higher critical thermal minimum (CT min 6.2°C) than hatchlings from cold incubation group (40.2 and 5.7°C, respectively). In the field, hatchlings typically settle under rocks near communal nests. During the hatching period, rock temperatures ranged from 13 to 59°C, and regularly exceeded the CT max of both hot- and cold-incubated hatchlings. Because rock temperatures were so high, the heat tolerance of lizards had little effect on their ability to exploit rocks as retreat sites. Instead, the timing of hatching dictated whether lizards could exploit rocks as retreat sites; that is, cold-incubated lizards that hatched later encountered less thermally stressful environments than earlier hatching hot-incubated lizards. In conclusion, we found no evidence that CT max can shift upwards in response to higher incubation temperatures, suggesting that hotter summers may increase the vulnerability of lizards to climate warming. © 2017. Published by The Company of Biologists Ltd.

  12. 76 FR 75858 - Endangered and Threatened Wildlife and Plants; 6-Month Extension of Final Determination for the...

    Science.gov (United States)

    2011-12-05

    ... of Final Determination for the Proposed Listing of the Dunes Sagebrush Lizard as Endangered AGENCY... of whether to list the dunes sagebrush lizard (Sceloporus arenicolus) (lizard) as endangered and... published a proposed rule (75 FR 77801) to list the dunes sagebrush lizard, a lizard known from southeastern...

  13. The Ins & Outs of Developing a Field-Based Science Project: Learning by Lassoing Lizards

    Science.gov (United States)

    Matthews, Catherine E.; Huffling, Lacey D.; Benavides, Aerin

    2014-01-01

    We describe a field-based lizard project we did with high school students as a part of our summer Herpetological Research Experiences. We describe data collection on lizards captured, identified, and marked as a part of our mark-recapture study. We also describe other lizard projects that are ongoing in the United States and provide resources for…

  14. Spatial, ontogenetic and sexual effects on the diet of a Teiid lizard in arid South America

    NARCIS (Netherlands)

    Leeuwen, van J.P.; Catenazzi, A.; Holmgren, M.

    2011-01-01

    Most lizard species feed on small arthropods, and although some are omnivorous, only a few species are strict herbivores. We studied the diet of Dicrodon guttulatum, a teiid lizard endemic to the arid coastal deserts and dry forests of northern Peru. Herbivory by this lizard has been identified as a

  15. Testing the effects of perimeter fencing and elephant exclosures on lion predation patterns in a Kenyan wildlife conservancy.

    Science.gov (United States)

    Dupuis-Desormeaux, Marc; Davidson, Zeke; Pratt, Laura; Mwololo, Mary; MacDonald, Suzanne E

    2016-01-01

    The use of fences to segregate wildlife can change predator and prey behaviour. Predators can learn to incorporate fencing into their hunting strategies and prey can learn to avoid foraging near fences. A twelve-strand electric predator-proof fence surrounds our study site. There are also porous one-strand electric fences used to create exclosures where elephant (and giraffe) cannot enter in order to protect blocs of browse vegetation for two critically endangered species, the black rhinoceros (Diceros bicornis) and the Grevy's zebra (Equus grevyi). The denser vegetation in these exclosures attracts both browsing prey and ambush predators. In this study we examined if lion predation patterns differed near the perimeter fencing and inside the elephant exclosures by mapping the location of kills. We used a spatial analysis to compare the predation patterns near the perimeter fencing and inside the exclosures to predation in the rest of the conservancy. Predation was not over-represented near the perimeter fence but the pattern of predation near the fence suggests that fences may be a contributing factor to predation success. Overall, we found that predation was over-represented inside and within 50 m of the exclosures. However, by examining individual exclosures in greater detail using a hot spot analysis, we found that only a few exclosures contained lion predation hot spots. Although some exclosures provide good hunting grounds for lions, we concluded that exclosures did not necessarily create prey-traps per se and that managers could continue to use this type of exclusionary fencing to protect stands of dense vegetation.

  16. Testing the effects of perimeter fencing and elephant exclosures on lion predation patterns in a Kenyan wildlife conservancy

    Directory of Open Access Journals (Sweden)

    Marc Dupuis-Desormeaux

    2016-02-01

    Full Text Available The use of fences to segregate wildlife can change predator and prey behaviour. Predators can learn to incorporate fencing into their hunting strategies and prey can learn to avoid foraging near fences. A twelve-strand electric predator-proof fence surrounds our study site. There are also porous one-strand electric fences used to create exclosures where elephant (and giraffe cannot enter in order to protect blocs of browse vegetation for two critically endangered species, the black rhinoceros (Diceros bicornis and the Grevy’s zebra (Equus grevyi. The denser vegetation in these exclosures attracts both browsing prey and ambush predators. In this study we examined if lion predation patterns differed near the perimeter fencing and inside the elephant exclosures by mapping the location of kills. We used a spatial analysis to compare the predation patterns near the perimeter fencing and inside the exclosures to predation in the rest of the conservancy. Predation was not over-represented near the perimeter fence but the pattern of predation near the fence suggests that fences may be a contributing factor to predation success. Overall, we found that predation was over-represented inside and within 50 m of the exclosures. However, by examining individual exclosures in greater detail using a hot spot analysis, we found that only a few exclosures contained lion predation hot spots. Although some exclosures provide good hunting grounds for lions, we concluded that exclosures did not necessarily create prey-traps per se and that managers could continue to use this type of exclusionary fencing to protect stands of dense vegetation.

  17. GPS and Electronic Fence Data Fusion for Positioning within Railway Worksite Scenarios

    DEFF Research Database (Denmark)

    Figueiras, Joao; Grønbæk, Lars Jesper; Ceccarelli, Andrea

    2012-01-01

    Context-dependent decisions in safety-critical applications require careful consideration of accuracy and timeliness of the underlying context information. Relevant examples include location-dependent actions in mobile distributed systems. This paper considers localization functions for personali......Context-dependent decisions in safety-critical applications require careful consideration of accuracy and timeliness of the underlying context information. Relevant examples include location-dependent actions in mobile distributed systems. This paper considers localization functions...... with information from the electronic fences is developed and analyzed. Different accuracy metrics are proposed and the benefit obtained from the fusion with electronic fences is quantitatively analyzed in the scenarios of a single mobile entity: By having fence information, the correct zone estimation can increase...... by 30%, while false alarms can be reduced one order of magnitude in the tested scenario....

  18. Why tropical forest lizards are vulnerable to climate warming

    Science.gov (United States)

    Huey, Raymond B.; Deutsch, Curtis A.; Tewksbury, Joshua J.; Vitt, Laurie J.; Hertz, Paul E.; Álvarez Pérez, Héctor J.; Garland, Theodore

    2009-01-01

    Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their physiological sensitivity to warming and their options for behavioural and physiological compensation. Lizards are useful for evaluating risks of warming because their thermal biology is well studied. We conducted macrophysiological analyses of diurnal lizards from diverse latitudes plus focal species analyses of Puerto Rican Anolis and Sphaerodactyus. Although tropical lowland lizards live in environments that are warm all year, macrophysiological analyses indicate that some tropical lineages (thermoconformers that live in forests) are active at low body temperature and are intolerant of warm temperatures. Focal species analyses show that some tropical forest lizards were already experiencing stressful body temperatures in summer when studied several decades ago. Simulations suggest that warming will not only further depress their physiological performance in summer, but will also enable warm-adapted, open-habitat competitors and predators to invade forests. Forest lizards are key components of tropical ecosystems, but appear vulnerable to the cascading physiological and ecological effects of climate warming, even though rates of tropical warming may be relatively low. PMID:19324762

  19. Wind constraints on the thermoregulation of high mountain lizards

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2017-03-01

    Thermal biology of lizards affects their overall physiological performance. Thus, it is crucial to study how abiotic constraints influence thermoregulation. We studied the effect of wind speed on thermoregulation in an endangered mountain lizard ( Iberolacerta aurelioi). We compared two populations of lizards: one living in a sheltered rocky area and the other living in a mountain ridge, exposed to strong winds. The preferred temperature range of I. aurelioi, which reflects thermal physiology, was similar in both areas, and it was typical of a cold specialist. Although the thermal physiology of lizards and the structure of the habitat were similar, the higher wind speed in the exposed population was correlated with a significant decrease in the effectiveness thermoregulation, dropping from 0.83 to 0.74. Our results suggest that wind reduces body temperatures in two ways: via direct convective cooling of the animal and via convective cooling of the substrate, which causes conductive cooling of the animal. The detrimental effect of wind on thermoregulatory effectiveness is surprising, since lizards are expected to thermoregulate more effectively in more challenging habitats. However, wind speed would affect the costs and benefits of thermoregulation in more complex ways than just the cooling of animals and their habitats. For example, it may reduce the daily activity, increase desiccation, or complicate the hunting of prey. Finally, our results imply that wind should also be considered when developing conservation strategies for threatened ectotherms.

  20. The ability of ewes with lambs to learn a virtual fencing system.

    Science.gov (United States)

    Brunberg, E I; Bergslid, I K; Bøe, K E; Sørheim, K M

    2017-11-01

    The Nofence technology is a GPS-based virtual fencing system designed to keep sheep within predefined borders, without using physical fences. Sheep wearing a Nofence collar receive a sound signal when crossing the virtual border and a weak electric shock if continuing to walk out from the virtual enclosure. Two experiments testing the functionality of the Nofence system and a new learning protocol is described. In Experiment 1, nine ewes with their lambs were divided into groups of three and placed in an experimental enclosure with one Nofence border. During 2 days, there was a physical fence outside the border, during Day 3 the physical fence was removed and on Day 4, the border was moved to the other end of the enclosure. The sheep received between 6 and 20 shocks with an average of 10.9±2.0 (mean±SE) per ewe during all 4 days. The number of shocks decreased from 4.38±0.63 on Day 3 (when the physical fence was removed) to 1.5±0.71 on Day 4 (when the border was moved). The ewes spent on average 3%, 6%, 46% and 9% of their time outside the border on Days 1, 2, 3 and 4, respectively. In Experiment 2, 32 ewes, with and without lambs, were divided into groups of eight and placed in an experimental enclosure. On Day 1, the enclosure was fenced with three physical fences and one virtual border, which was then increased to two virtual borders on Day 2. To continue to Day 3, when there was supposed to be three virtual borders on the enclosure, at least 50% of the ewes in a group should have received a maximum of four shocks on Day 2. None of the groups reached this learning criterion and the experiment ended after Day 2. The sheep received 4.1±0.32 shocks on Day 1 and 4.7±0.28 shocks on Day 2. In total, 71% of the ewes received the maximum number of five shocks on Day 1 and 77% on Day 2. The individual ewes spent between 0% and 69.5% of Day 1 in the exclusion zone and between 0% and 64% on Day 2. In conclusion, it is too challenging to ensure an efficient learning

  1. Bone indicators of grasping hands in lizards

    Directory of Open Access Journals (Sweden)

    Gabriela Fontanarrosa

    2016-05-01

    Full Text Available Grasping is one of a few adaptive mechanisms that, in conjunction with clinging, hooking, arm swinging, adhering, and flying, allowed for incursion into the arboreal eco-space. Little research has been done that addresses grasping as an enhanced manual ability in non-mammalian tetrapods, with the exception of studies comparing the anatomy of muscle and tendon structure. Previous studies showed that grasping abilities allow exploitation for narrow branch habitats and that this adaptation has clear osteological consequences. The objective of this work is to ascertain the existence of morphometric descriptors in the hand skeleton of lizards related to grasping functionality. A morphological matrix was constructed using 51 morphometric variables in 278 specimens, from 24 genera and 13 families of Squamata. To reduce the dimensions of the dataset and to organize the original variables into a simpler system, three PCAs (Principal Component Analyses were performed using the subsets of (1 carpal variables, (2 metacarpal variables, and (3 phalanges variables. The variables that demonstrated the most significant contributions to the construction of the PCA synthetic variables were then used in subsequent analyses. To explore which morphological variables better explain the variations in the functional setting, we ran Generalized Linear Models for the three different sets. This method allows us to model the morphology that enables a particular functional trait. Grasping was considered the only response variable, taking the value of 0 or 1, while the original variables retained by the PCAs were considered predictor variables. Our analyses yielded six variables associated with grasping abilities: two belong to the carpal bones, two belong to the metacarpals and two belong to the phalanges. Grasping in lizards can be performed with hands exhibiting at least two different independently originated combinations of bones. The first is a combination of a highly

  2. Fencing network direct memory access data transfers in a parallel active messaging interface of a parallel computer

    Science.gov (United States)

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-07-07

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to a deterministic data communications network through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and the deterministic data communications network; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  3. Seasonal reproductive endothermy in tegu lizards

    Science.gov (United States)

    Tattersall, Glenn J.; Leite, Cleo A. C.; Sanders, Colin E.; Cadena, Viviana; Andrade, Denis V.; Abe, Augusto S.; Milsom, William K.

    2016-01-01

    With some notable exceptions, small ectothermic vertebrates are incapable of endogenously sustaining a body temperature substantially above ambient temperature. This view was challenged by our observations of nighttime body temperatures sustained well above ambient (up to 10°C) during the reproductive season in tegu lizards (~2 kg). This led us to hypothesize that tegus have an enhanced capacity to augment heat production and heat conservation. Increased metabolic rates and decreased thermal conductance are the same mechanisms involved in body temperature regulation in those vertebrates traditionally acknowledged as “true endotherms”: the birds and mammals. The appreciation that a modern ectotherm the size of the earliest mammals can sustain an elevated body temperature through metabolic rates approaching that of endotherms enlightens the debate over endothermy origins, providing support for the parental care model of endothermy, but not for the assimilation capacity model of endothermy. It also indicates that, contrary to prevailing notions, ectotherms can engage in facultative endothermy, providing a physiological analog in the evolutionary transition to true endothermy. PMID:26844295

  4. Seasonal reproductive endothermy in tegu lizards.

    Science.gov (United States)

    Tattersall, Glenn J; Leite, Cleo A C; Sanders, Colin E; Cadena, Viviana; Andrade, Denis V; Abe, Augusto S; Milsom, William K

    2016-01-01

    With some notable exceptions, small ectothermic vertebrates are incapable of endogenously sustaining a body temperature substantially above ambient temperature. This view was challenged by our observations of nighttime body temperatures sustained well above ambient (up to 10°C) during the reproductive season in tegu lizards (~2 kg). This led us to hypothesize that tegus have an enhanced capacity to augment heat production and heat conservation. Increased metabolic rates and decreased thermal conductance are the same mechanisms involved in body temperature regulation in those vertebrates traditionally acknowledged as "true endotherms": the birds and mammals. The appreciation that a modern ectotherm the size of the earliest mammals can sustain an elevated body temperature through metabolic rates approaching that of endotherms enlightens the debate over endothermy origins, providing support for the parental care model of endothermy, but not for the assimilation capacity model of endothermy. It also indicates that, contrary to prevailing notions, ectotherms can engage in facultative endothermy, providing a physiological analog in the evolutionary transition to true endothermy.

  5. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Science.gov (United States)

    Gleeson, Dianne; Georges, Arthur

    2018-01-01

    Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata) which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways. PMID:29751579

  6. A forebrain atlas of the lizard Gekko gecko.

    Science.gov (United States)

    Smeets, W J; Hoogland, P V; Lohman, A H

    1986-12-01

    An atlas of the forebrain of the lizard Gekko gecko has been provided, which will serve as the basis for subsequent experimental tracing and immunohistochemical studies. Apart from a strongly developed medial cortex and septal area, the Tokay gecko shows all the main features of the forebrain of the lacertid-type lizards. When its convenience as an experimental animal is also taken into account, this species seems to be very suitable for studying the limbic system in reptiles. The atlas comprises topographical reconstructions of the telencephalon and diencephalon and a series of transverse sections of which the levels have been indicated in the reconstructions. The results obtained in the Gekko are briefly compared with those found in other lizards studied.

  7. The auditory brainstem response in two lizard species

    DEFF Research Database (Denmark)

    Brittan-Powell, Elizabeth F; Christensen-Dalsgaard, Jakob; Tang, Yezhong

    2010-01-01

    Although lizards have highly sensitive ears, it is difficult to condition them to sound, making standard psychophysical assays of hearing sensitivity impractical. This paper describes non-invasive measurements of the auditory brainstem response (ABR) in both Tokay geckos (Gekko gecko; nocturnal...... animals, known for their loud vocalizations) and the green anole (Anolis carolinensis, diurnal, non-vocal animals). Hearing sensitivity was measured in 5 geckos and 7 anoles. The lizards were sedated with isoflurane, and ABRs were measured at levels of 1 and 3% isoflurane. The typical ABR waveform......). Above 5 kHz, however, anoles were more than 20 dB more sensitive than geckos and showed a wider range of sensitivity (1-7 kHz). Generally, thresholds from ABR audiograms were comparable to those of small birds. Best hearing sensitivity, however, extended over a larger frequency range in lizards than...

  8. Nematodes Parasites of Teiid Lizards from the Brazilian Amazon Rainforest.

    Science.gov (United States)

    Macedo, L C; Gardner, S L; Melo, F T V; Giese, E G; Santos, J N

    2017-04-01

    This study presents the helminth composition and parameters of infection by several species of nematodes in teiid lizards, Ameiva ameiva ameiva (Linnaeus, 1758), Cnemidophorus cryptus Cole and Dessauer, 1993, and Kentropyx calcarata Spix, 1825 from the Brazilian Amazonian Rainforest. The population of lizards studied were parasitized by 6 species of Phylum Nemata including: Spinicauda spinicauda (Olfers, 1919), Parapharyngodon alvarengai Freitas, 1957, Physaloptera sp. (adults), Physaloptera sp. (larvae), Piratuba digiticauda Lent and Freitas, 1941, and Anisakidae (larvae). The overall prevalence was 66.17% and the mean intensity of infection was 19.40 ± 25.48. The association between the body-length of lizards and the abundance and richness of parasitic nematodes was statistically significant only in Ameiva a. ameiva. A new host record is reported here with 1 specimen of the family Anasakidae in Ameiva a. ameiva. Both S. spinicauda and Physaloptera sp. represent new records from C. cryptus.

  9. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Directory of Open Access Journals (Sweden)

    Shayer Mahmood Ibney Alam

    2018-05-01

    Full Text Available Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD and temperature-dependent sex determination (TSD within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways.

  10. Spontaneous magnetic alignment behaviour in free-living lizards

    Science.gov (United States)

    Diego-Rasilla, Francisco J.; Pérez-Mellado, Valentín; Pérez-Cembranos, Ana

    2017-04-01

    Several species of vertebrates exhibit spontaneous longitudinal body axis alignment relative to the Earth's magnetic field (i.e., magnetic alignment) while they are performing different behavioural tasks. Since magnetoreception is still not fully understood, studying magnetic alignment provides evidence for magnetoreception and broadens current knowledge of magnetic sense in animals. Furthermore, magnetic alignment widens the roles of magnetic sensitivity in animals and may contribute to shed new light on magnetoreception. In this context, spontaneous alignment in two species of lacertid lizards ( Podarcis muralis and Podarcis lilfordi) during basking periods was monitored. Alignments in 255 P. muralis and 456 P. lilfordi were measured over a 5-year period. The possible influence of the sun's position (i.e., altitude and azimuth) and geomagnetic field values corresponding to the moment in which a particular lizard was observed on lizards' body axis orientation was evaluated. Both species exhibited a highly significant bimodal orientation along the north-northeast and south-southwest magnetic axis. The evidence from this study suggests that free-living lacertid lizards exhibit magnetic alignment behaviour, since their body alignments cannot be explained by an effect of the sun's position. On the contrary, lizard orientations were significantly correlated with geomagnetic field values at the time of each observation. We suggest that this behaviour might provide lizards with a constant directional reference while they are sun basking. This directional reference might improve their mental map of space to accomplish efficient escape behaviour. This study is the first to provide spontaneous magnetic alignment behaviour in free-living reptiles.

  11. Earliest example of a giant monitor lizard (Varanus, Varanidae, Squamata.

    Directory of Open Access Journals (Sweden)

    Jack L Conrad

    Full Text Available BACKGROUND: Varanidae is a clade of tiny (600 mm PCL lizards first appearing in the Cretaceous. True monitor lizards (Varanus are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis, although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. METHODOLOGY/PRINCIPAL FINDINGS: A new Varanus from the Mytilini Formation (Turolian, Miocene of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. CONCLUSIONS/SIGNIFICANCE: The new monitor is larger (longer than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors.

  12. Tail-assisted pitch control in lizards, robots and dinosaurs.

    Science.gov (United States)

    Libby, Thomas; Moore, Talia Y; Chang-Siu, Evan; Li, Deborah; Cohen, Daniel J; Jusufi, Ardian; Full, Robert J

    2012-01-04

    In 1969, a palaeontologist proposed that theropod dinosaurs used their tails as dynamic stabilizers during rapid or irregular movements, contributing to their depiction as active and agile predators. Since then the inertia of swinging appendages has been implicated in stabilizing human walking, aiding acrobatic manoeuvres by primates and rodents, and enabling cats to balance on branches. Recent studies on geckos suggest that active tail stabilization occurs during climbing, righting and gliding. By contrast, studies on the effect of lizard tail loss show evidence of a decrease, an increase or no change in performance. Application of a control-theoretic framework could advance our general understanding of inertial appendage use in locomotion. Here we report that lizards control the swing of their tails in a measured manner to redirect angular momentum from their bodies to their tails, stabilizing body attitude in the sagittal plane. We video-recorded Red-Headed Agama lizards (Agama agama) leaping towards a vertical surface by first vaulting onto an obstacle with variable traction to induce a range of perturbations in body angular momentum. To examine a known controlled tail response, we built a lizard-sized robot with an active tail that used sensory feedback to stabilize pitch as it drove off a ramp. Our dynamics model revealed that a body swinging its tail experienced less rotation than a body with a rigid tail, a passively compliant tail or no tail. To compare a range of tails, we calculated tail effectiveness as the amount of tailless body rotation a tail could stabilize. A model Velociraptor mongoliensis supported the initial tail stabilization hypothesis, showing as it did a greater tail effectiveness than the Agama lizards. Leaping lizards show that inertial control of body attitude can advance our understanding of appendage evolution and provide biological inspiration for the next generation of manoeuvrable search-and-rescue robots.

  13. Does thermal ecology influence dynamics of side-blotched lizards and their micro-parasites?

    Science.gov (United States)

    Paranjpe, Dhanashree A; Medina, Dianna; Nielsen, Erica; Cooper, Robert D; Paranjpe, Sharayu A; Sinervo, Barry

    2014-07-01

    Hosts and parasites form interacting populations that influence each other in multiple ways. Their dynamics can also be influenced by environmental and ecological factors. We studied host-parasite dynamics in a previously unexplored study system: side-blotched lizards and their micro-parasites. Compared with uninfected lizards, the infected lizards elected to bask at lower temperatures that were outside their range of preferred temperatures. Infected lizards also were not as precise as uninfected lizards in maintaining their body temperatures within a narrow range. At the ecological scale, areas with higher infection rates coincided with more thermally heterogeneous microhabitats as well as with the areas where lizards tended to live longer. Thermal heterogeneity of lizards' microhabitats may provide important clues to the spatial and temporal distribution of infections. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  14. Modifying Directionality through Auditory System Scaling in a Robotic Lizard

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    2010-01-01

    The peripheral auditory system of a lizard is strongly directional. This directionality is created by acoustical coupling of the two eardrums and is strongly dependent on characteristics of the middle ear, such as interaural distance, resonance frequency of the middle ear cavity and of the tympanum....... Therefore, directionality should be strongly influenced by their scaling. In the present study, we have exploited an FPGA–based mobile robot based on a model of the lizard ear to investigate the influence of scaling on the directional response, in terms of the robot’s performance in a phonotaxis task...

  15. Radiation induced leukemia and leukopenia in the lizard Uromastix hardwickii

    International Nuclear Information System (INIS)

    Ahmad, M.; Taqawi, I.H.

    1978-01-01

    The effect of 3,000 R, 3,500 R and 4,000 R on the total leukocyte counts of the lizard Uromastix hardwickii was observed for a period of six weeks. Exposure to 3,000 R resulted in ever rising leukocyte counts and the cells showed abnormal morphology. There was no primary transient leukocytosis prior to leukopenia after exposure to 3,500 R, and no abortive leukocytosis prior to leukopenia in the 4,000 R lizards. Thus, the dose of 3,000 R induces leukemia and the doses of 3,500 and 4,000 R produce leukopenia. (author)

  16. An armored-cable-based fiber Bragg grating sensor array for perimeter fence intrusion detection

    Science.gov (United States)

    Hao, Jianzhong; Dong, Bo; Varghese, Paulose; Phua, Jiliang; Foo, Siang Fook

    2012-01-01

    In this paper, an armored-cable-based optical fiber Bragg grating (FBG) sensor array, for perimeter fence intrusion detection, is demonstrated and some of the field trial results are reported. The field trial was conducted at a critical local installation in Singapore in December 2010. The sensor array was put through a series of both simulated and live intrusion scenarios to test the stability and suitability of operation in the local environmental conditions and to determine its capabilities in detecting and reporting these intrusions accurately to the control station. Such a sensor array can provide perimeter intrusion detection with fine granularity and preset pin-pointing accuracy. The various types of intrusions included aided or unaided climbs, tampering and cutting of the fence, etc. The unique sensor packaging structure provides high sensitivity, crush resistance and protection against rodents. It is also capable of resolving nuisance events such as rain, birds sitting on the fence or seismic vibrations. These sensors are extremely sensitive with a response time of a few seconds. They can be customized for a desired spatial resolution and pre-determined sensitivity. Furthermore, it is easy to cascade a series of such sensors to monitor and detect intrusion events over a long stretch of fence line. Such sensors can be applied to real-time intrusion detection for perimeter security, pipeline security and communications link security.

  17. Responses of northern red oak seedlings to lime and deer exclosure fencing in Pennsylvania

    Science.gov (United States)

    Robert P. Long; Patrick H. Brose; Stephen B. Horsley

    2012-01-01

    In Pennsylvania, two hypotheses compete to explain the chronic oak (Quercus spp.) regeneration problem: excessive deer browsing and soil cation depletion. We tested these hypotheses by evaluating the effect of forest liming and deer exclosure fencing on northern red oak (Quercus rubra L.) seedling growth and nutrition in five...

  18. The Chain-Link Fence Model: A Framework for Creating Security Procedures

    Science.gov (United States)

    Houghton, Robert F.

    2013-01-01

    A long standing problem in information technology security is how to help reduce the security footprint. Many specific proposals exist to address specific problems in information technology security. Most information technology solutions need to be repeatable throughout the course of an information systems lifecycle. The Chain-Link Fence Model is…

  19. Bridging the divide: Middle Eastern walls and fences and the spatial governance of problem populations

    NARCIS (Netherlands)

    Pallister-Wilkins, P.

    2015-01-01

    Building on a long history of spatial control through walling in the region, walls and fences have been built in the Middle East in recent years to undertake a range of practices. Gated communities, residential and security compounds, anti-migrant walls, separation barriers and counter-insurgency

  20. Elephant crop damage and electric fence construction in the Maputo Elephant Reserve, Mozambique

    NARCIS (Netherlands)

    Boer, de W.F.; Ntumi, C.P.

    2001-01-01

    An electric fence is at present being constructed around the Maputo Elephant Reserve, Mozambique, to protect farmers from elephant raids. Elephants cause crop damage, estimated at US$ 8800 yr-1, or US$ 50 elephant-1. Elephants preferred maize, melons and beans and their raid frequency increased

  1. Stress Reduction and Mood Enhancement in Four Exercise Modes: Swimming, Body Conditioning, Hatha Yoga, and Fencing.

    Science.gov (United States)

    Berger, Bonnie G.; Owen, David R.

    1988-01-01

    Differences in mood before and after class of college students taking different courses (swimming, body conditioning, hatha yoga, fencing exercise, and lecture) were analyzed using the Profile Mood States and the State Anxiety Inventory. Results suggest that courses which meet four requirements involving aerobics, noncompetitiveness,…

  2. The effects of fences and lions on the ecology of African wild dogs ...

    African Journals Online (AJOL)

    Movement patters and den site locations suggested that dogs avoided the presence of lions. Major prey species were kudu (50 %), impala (32 %) and waterbuck (14 %). Large prey, including adult male kudu (250 kg) and waterbuck (260 kg) were taken regularly through use of the boundary fence as an aid to capture.

  3. Evolution of Anolis lizard dewlap diversity.

    Directory of Open Access Journals (Sweden)

    Kirsten E Nicholson

    Full Text Available BACKGROUND: The dewlaps of Anolis lizards provide a classic example of a complex signaling system whose function and evolution is poorly understood. Dewlaps are flaps of skin beneath the chin that are extended and combined with head and body movements for visual signals and displays. They exhibit extensive morphological variation and are one of two cladistic features uniting anoles, yet little is known regarding their function and evolution. We quantified the diversity of anole dewlaps, investigated whether dewlap morphology was informative regarding phylogenetic relationships, and tested two separate hypotheses: (A similar Anolis habitat specialists possess similar dewlap configurations (Ecomorph Convergence hypothesis, and (B sympatric species differ in their dewlap morphologies to a greater extent than expected by chance (Species Recognition hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: We found that dewlap configurations (sizes, patterns and colors exhibit substantial diversity, but that most are easily categorized into six patterns that incorporate one to three of 13 recognizable colors. Dewlap morphology is not phylogenetically informative and, like other features of anoles, exhibits convergence in configurations. We found no support for the Ecomorph Convergence hypothesis; species using the same structural habitat were no more similar in dewlap configuration than expected by chance. With one exception, all sympatric species in four communities differ in dewlap configuration. However, this provides only weak support for the Species Recognition hypothesis because, due to the great diversity in dewlap configurations observed across each island, few cases of sympatric species with identical dewlaps would be expected to co-occur by chance alone. CONCLUSIONS/SIGNIFICANCE: Despite previous thought, most dewlaps exhibit easily characterizable patterns and colorations. Nevertheless, dewlap variation is extensive and explanations for the origin and

  4. P16.17 Usefulness of neuronavigator-guided fence-post method for malignant glioma resection

    Science.gov (United States)

    Murase, S.; Yamashita, K.

    2017-01-01

    Abstract For the resection of malignant glioma, it is necessary to remove the tumor as much as possible and to avoid the expression of new neurological deficit. For this purpose, we adopted neuronavigator-guided fence-post method for malignant glioma resection in 2015. In this presentation, we will introduce this method and evaluate the usefulness of this method. Method:On one or two day before the surgery, fence-post plan is laid according to the MR images on neuronavigator system(StealthStation S7, Medtronic). Usually four fence-post are planned to involve all part of enhanced lesion of the tumor. If the tumor is located close to the pyramidal tracts, MR tractography image is also integrated in the navigator system, and fence-post are planned to avoid damaging the pyramidal tracts. During the surgery, after the craniotomy each fence-post catheter is placed according to the navigator guidance before the dural incision to avoid the influence of brain shift. After the dural incision, four planes created by adjacent each fence-post catheter are resected and the tumor is removed. Result: We will present typical three cases. Two cases of glioblastoma and one case of anaplastic oligodendroglioma case are presented. In all three cases, the tumor were located in the left frontal lobe and the tumor were gross totally removed without new neurological deficit with this method. CONCLUSION: Neuronavigator-guided fence-post method is very useful for the resection of malignant glioma.

  5. Prey, but not plant, chemical discrimination by the lizard ...

    African Journals Online (AJOL)

    We experimentally studied responses to food chemicals by Gerrhosaurus nigrolineatus, amember of a lizard genus endemic to subsaharan Africa. Gerrhosaur diets vary from insectivorous to omnivorous with a very large plant portion. The omnivorous G. validus responds strongly to chemical cues from prey and food plants.

  6. Ecological release in lizard assemblages of neotropical savannas.

    Science.gov (United States)

    Mesquita, Daniel Oliveira; Colli, Guarino Rinaldi; Vitt, Laurie J

    2007-08-01

    We compare lizard assemblages of Cerrado and Amazonian savannas to test the ecological release hypothesis, which predicts that niche dimensions and abundance should be greater in species inhabiting isolated habitat patches with low species richness (Amazonian savannas and isolated Cerrado patches) when compared with nonisolated areas in central Cerrado with greater species richness. We calculated microhabitat and diet niche breadths with data from 14 isolated Cerrado patches and Amazon savanna areas and six central Cerrado populations. Morphological data were compared using average Euclidean distances, and lizard abundance was estimated using the number of lizards captured in pitfall traps over an extended time period. We found no evidence of ecological release with respect to microhabitat use, suggesting that historical factors are better microhabitat predictors than ecological factors. However, data from individual stomachs indicate that ecological release occurs in these areas for one species (Tropidurus) but not others (Ameiva ameiva, Anolis, Cnemidophorus, and Micrablepharus), suggesting that evolutionary lineages respond differently to environmental pressures, with tropidurids being more affected by ecological factors than polychrotids, teiids, and gymnophthalmids. We found no evidence that ecological release occurs in these areas using morphological data. Based on abundance data, our results indicate that the ecological release (density compensation) hypothesis is not supported: lizard species are not more abundant in isolated areas than in nonisolated areas. The ecology of species is highly conservative, varying little from assemblage to assemblage. Nevertheless, increases in niche breadth for some species indicate that ecological release occurs as well.

  7. The female reproductive cycle of the lizard, Cordylus polyzonus ...

    African Journals Online (AJOL)

    1987-11-13

    Nov 13, 1987 ... mass of the embryos versus newly ovulated eggs indica- ted that a loss of 15,9% ... Figure 4 Summary of follicular (dark shaded) and luteal activity (light shaded) during gestation in the lizard, C. p. polyzonus. AIl values are .... inadequate energy intake to meet the increased metabo- lic demand during this ...

  8. Paradoxical reproduction and body size in the rock lizard, Agama ...

    African Journals Online (AJOL)

    1993-07-05

    Jul 5, 1993 ... The rock lizard Agama atra atra from Namaqualand differs in both body size and reproduction from other populations of this species occurring elsewhere in southern Africa. Both sexes from Namaqualand are significantly larger than their counterparts in the south-western Cape. While reproduction in this ...

  9. A survey of the mammals, lizards and mollusks

    NARCIS (Netherlands)

    NN,

    1940-01-01

    This annotated list of the mammals, lizards and mollusks of the Leeward Group, is based on author’s collection and therefore includes additional mainland-records of the island-species. As a rule a short commentary is given only as a guide to the adopted nomenclature and classification, in case of

  10. Technique for Measuring Speed and Visual Motion Sensitivity in Lizards

    Science.gov (United States)

    Woo, Kevin L.; Burke, Darren

    2008-01-01

    Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics.…

  11. Modelling asymmetry in the peripheral auditory system of the lizard

    DEFF Research Database (Denmark)

    Zhang, Lei; Hallam, John; Christensen-Dalsgaard, Jakob

    2008-01-01

    The ears of lizards are highly directional. The directionality is generated by strong acoustical coupling of the eardrums. A simple lumped-parameter model of the ear followed by binaural comparisons has been shown to perform successful phonotaxis in robot implementations. However, such a model...

  12. Extended molecular phylogenetics and revised systematics of Malagasy scincine lizards

    NARCIS (Netherlands)

    Erens, Jesse; Miralles, A.; Glaw, F.; Chatrou, L.W.; Vences, M.

    2017-01-01

    Among the endemic biota of Madagascar, skinks are a diverse radiation of lizards that exhibit a striking ecomorphological variation, and could provide an interesting system to study body-form evolution in squamate reptiles. We provide a new phylogenetic hypothesis for Malagasy skinks of the

  13. Learning to Localize Sound with a Lizard Ear Model

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    The peripheral auditory system of a lizard is strongly directional in the azimuth plane due to the acoustical coupling of the animal's two eardrums. This feature by itself is insufficient to accurately localize sound as the extracted directional information cannot be directly mapped to the sound...

  14. Rain-harvesting behavior in agamid lizards (Trapelus)

    Czech Academy of Sciences Publication Activity Database

    Veselý, M.; Modrý, David

    2002-01-01

    Roč. 36, č. 2 (2002), s. 311-314 ISSN 0022-1511 Institutional research plan: CEZ:AV0Z6022909 Keywords : lizards * ethology * rain-harvesting behavior Subject RIV: EG - Zoology Impact factor: 0.649, year: 2002

  15. Structure and function of the hearts of lizards and snakes

    NARCIS (Netherlands)

    Jensen, Bjarke; Moorman, Antoon F. M.; Wang, Tobias

    2014-01-01

    With approximately 7000 species, snakes and lizards, collectively known as squamates, are by far the most species-rich group of reptiles. It was from reptile-like ancestors that mammals and birds evolved and squamates can be viewed as phylogenetically positioned between them and fishes. Hence, their

  16. Reproductive strategies in males of the world's southernmost lizards.

    Science.gov (United States)

    Fernández, Jimena B; Medina, Marlin; Kubisch, Erika L; Scolaro, José A; Ibargüengoytía, Nora R

    2017-03-01

    Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold temperate climates of high altitudes or latitudes in Argentina and Chile, have developed a variety of reproductive cycles to coordinate with the short female reproductive season and to deal with the low frequency of reproductive females in the population. Using gonadal histology and morphological analysis, we describe the male reproductive biology, fat storage and sexual dimorphism of the viviparous lizards Liolaemus sarmientoi and Liolaemus magellanicus that inhabit an austral grass steppe at 51°S, in the southern limit of the American continent. Males of L. sarmientoi and L. magellanicus are reproductively available during the entire activity season of approximately 5 months. In addition, males of both species exhibit greater body sizes than females in morphological variables relevant in sexual selection. Meanwhile, females of both species exhibit larger inter-limb length than conspecific males, which suggests fecundity selection to increase space for a larger litter size. The continuous sperm production throughout the activity season allows these liolaemids to mate at any time when females ovulate, representing a selective advantage to deal with the short activity season and the adversities of the cold environment they inhabit. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  17. Leaping Lizards And Learning. In the Curriculum: Science

    Science.gov (United States)

    Petersen, Diane; Nelson, Cathi

    2004-01-01

    In the broad fields that stretch toward the horizon in the Columbia Basin region of Washington state, the land is just right for at least two purposes: growing dryland wheat and providing habitat for shorthorned lizards, also known as horny toads. Our elementary school, enrolling 150 children from this rural farming community, has become a hub for…

  18. Microhabitat choice in island lizards enhances camouflage against avian predators.

    Science.gov (United States)

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2016-01-25

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation.

  19. Lizard\\'s fauna of the Sabzevar with particular emphasis on the syntopic lizard and presentation of a framework for reptile distribution of Iran

    Directory of Open Access Journals (Sweden)

    Masoud Yousefi

    2013-11-01

    Full Text Available Sabzevar is one of the most biologically diverse regions in northeast Iran, with the area of 19500 km2 and an elevational of 950-2977 m. During a long term study of lizards in this area which lasted 3 years, 21 species and subspecies of lizards belonging to 13 genera and 5 families were collected, recognized and reported. The families Anguidae, Eublepharidae and Uromastycidae were not represented in the area. The genus Eremias with 6 species was the most diverse genus in Sabzevar district. More emphasis was given to the syntopic reptiles. This showed that Trapelus agailis with having 18 syntopic species and Cyrtopodion caspium with no syntopic species were in the extreme sides. Due to our little knowledge on the distribution of reptiles in Iran, we designed a framework for providing a reptile's distribution map in Iran.

  20. BPA riparian fencing and alternative water development projects completed within Asotin Creek Watershed ; 2000 and 2001 Asotin Creek fencing final report of accomplishments

    International Nuclear Information System (INIS)

    Johnson, B.J.Bradley J.

    2002-01-01

    The Asotin County Conservation District (ACCD) is the primary entity coordinating habitat projects on both private and public lands within the Asotin Creek watershed. The watershed covers approximately 325 square miles in the Blue Mountains of southeastern Washington in Water Resource Inventory Area (WRIA) 35. According to Washington Department of Fish and Wildlife's (WDFW) Priority WRIA's by ''At-Risk Stock Significance Map'', it is the highest priority WRIA in southeastern Washington. Summer steelhead, bull trout, and Snake River spring chinook salmon which are listed under the Endangered Species Act (ESA), are present in the watershed. WDFW manages it as a Wild Steelhead Reserve; no hatchery fish have been released here since 1997. The ACCD has been working with landowners, Bonneville Power Administration (BPA), Washington State Conservation Commission (WCC), Natural Resource Conservation Service (NRCS), Washington Department of Fish and Wildlife (WDFW), U.S. Forest Service, Pomeroy Ranger District (USFS), Nez Perce Tribe, Washington Department of Ecology (DOE), National Marine Fisheries Service (NMFS), and U.S. Fish and Wildlife Service (USFWS) to address habitat projects in Asotin County. Local students, volunteers and Salmon Corps members from the Nez Perce Tribe have been instrumental in the success of the Model Watershed Program on Asotin Creek. ACCD began coordinating habitat projects in 1995 with the help of BPA funding. Approximately two hundred and seventy-six projects have been implemented as of 1999. The Washington State Legislature was successful in securing funding for endangered salmon and steelhead recovery throughout the State in 1998. While these issues were new to most of the State, the ACCD has been securing and administering funding for endangered salmonids since 1994. The ''Asotin Creek Riparian Planting 2000-053-00 and Asotin Creek Riparian Fencing 2000-054-00'' teamed BPA and the Governor's Salmon Recovery Funding to plant approximately 84

  1. The ability of lizards to identify an artificial Batesian mimic.

    Science.gov (United States)

    Beneš, Josef; Veselý, Petr

    2017-08-01

    Birds are usually considered the main predators shaping the evolution of aposematic signals and mimicry. Nevertheless, some lizards also represent predominately visually oriented predators, so they may also play an important role in the evolution of aposematism. Despite this fact, experimental evidence regarding the responses of lizards to aposematic prey is very poor compared to such evidence in birds. Lizards possess very similar sensory and cognitive abilities to those of birds and their response to aposematic prey may thus be affected by very similar processes. We investigated the reactions of a lizard, the Gran Canaria skink (Chalcides sexlineatus), to an aposematic prey and its artificial Batesian mimic. Further, we attempted to ascertain whether the lizard's food experience has any effect on its ability to recognise an artificial Batesian mimic, by using two groups of predators differing in their prior experience with the prey from which the mimic was fabricated. The red firebug (Pyrrhocoris apterus) was used as an aposematic model, and the Guyana spotted roach (Blaptica dubia) as the palatable prey from which the mimic was fabricated. The appearance of the roach was modified by a paper sticker placed on its back. The skinks showed a strong aversion towards the model firebug. They also avoided attacking the cockroaches with the firebug pattern sticker. This suggests that a visual rather than a chemical signal is responsible for this aversion. The protection provided by the firebug sticker was even effective when the skinks were familiar with unmodified cockroaches (previous food experience). Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Inclusive Training in Fencing as a Means of Changing Attitude to People with Disabilities

    Directory of Open Access Journals (Sweden)

    Р. Ю. Свічкар

    2015-09-01

    Full Text Available Research objective: to develop and improve the training of fencers using inclusive training in order to increase sport results and shape a positive attitude to people with disabilities. Methods. The co-training of the “Unifekht” Sports Club fencers and wheelchair fencers lasted for three months.  The athletes underwent the preliminary and the final testing on the target that showed a number of hits. Besides, during the individual lesson, the coach tested the athlete for the quality of performing attacking and defensive techniques. The preliminary and the final questionnaires revealed the opinions of the coaches, instructors of the Department of Fencing, fencers and wheelchair fencers and the students of the School of Physical Education and Sports of H. S. Skovoroda Kharkiv National Pedagogical University as to the attitude of the athletes of both categories to sports and “Invasport” in Ukraine. There were 40 respondents taking the questionnaires: 3rd-year students (10 people, fencers (10 people, instructors of the Department of Fencing (5 persons, wheelchair fencers (8 people, fencing coaches (5 persons, wheelchair fencing coaches (2 persons. Results. The study shows that, despite the high results of the athletes with disabilities, there exist certain problems in Ukraine that affect the willingness of people with disabilities to go in for sports. The main causes thereof are the low level of financial support and the low quality of medical care. By the research results, the respondents indicate the main criterion motivating people with special needs to do wheelchair fencing to be: self-expression and self-realization (68%, an opportunity to communicate (21%, and financial support (11%. The factors of low interest in wheelchair fencing are: lack of motivation to training people with special needs (26%; social policy of the state (23%; poor facilities and resources in the specialized institutions (20% of the respondents. At the same time

  3. Medical cautery units as a permanent and non-invasive method of marking lizards

    Directory of Open Access Journals (Sweden)

    Anna Ekner

    2011-12-01

    Full Text Available The identification of previously captured individuals is essential for a wide variety of ecological and behavioural studies. A lot of different methods are used for marking lizards, however they have many drawbacks. In presented study we used heat-branding method, using pen-like medical cautery units, previously employed to successfully mark other lizard species and snakes. The technique is permanent, readable and harmless for lizards, as well quick and easy. In 2009 we marked 111 individuals of sand lizard, Lacerta agilis. Next year we caught 88 lizards, 17 of them were re-captured. Among these re-captured lizards, five were caught after 26.8 (± 16.3 days (means in the same year and 12 after 308.8 (± 64.3 days (means in the next year. Recaptured individuals were still unambiguously recognisable.

  4. Rock-dwelling lizards exhibit less sensitivity of sprint speed to increases in substrate rugosity.

    Science.gov (United States)

    Collins, Clint E; Self, Jessica D; Anderson, Roger A; McBrayer, Lance D

    2013-06-01

    Effectively moving across variable substrates is important to all terrestrial animals. The effects of substrates on lizard performance have ecological ramifications including the partitioning of habitat according to sprinting ability on different surfaces. This phenomenon is known as sprint sensitivity, or the decrease in sprint speed due to change in substrate. However, sprint sensitivity has been characterized only in arboreal Anolis lizards. Our study measured sensitivity to substrate rugosity among six lizard species that occupy rocky, sandy, and/or arboreal habitats. Lizards that use rocky habitats are less sensitive to changes in substrate rugosity, followed by arboreal lizards, and then by lizards that use sandy habitats. We infer from comparative phylogenetic analysis that forelimb, chest, and tail dimensions are important external morphological features related to sensitivity to changes in substrate rugosity. Copyright © 2013 Elsevier GmbH. All rights reserved.

  5. Intermediate-band photosensitive device with quantum dots embedded in energy fence barrier

    Science.gov (United States)

    Forrest, Stephen R.; Wei, Guodan

    2010-07-06

    A plurality of layers of a first semiconductor material and a plurality of dots-in-a-fence barriers disposed in a stack between a first electrode and a second electrode. Each dots-in-a-fence barrier consists essentially of a plurality of quantum dots of a second semiconductor material embedded between and in direct contact with two layers of a third semiconductor material. Wave functions of the quantum dots overlap as at least one intermediate band. The layers of the third semiconductor material are arranged as tunneling barriers to require a first electron and/or a first hole in a layer of the first material to perform quantum mechanical tunneling to reach the second material within a respective quantum dot, and to require a second electron and/or a second hole in a layer of the first semiconductor material to perform quantum mechanical tunneling to reach another layer of the first semiconductor material.

  6. Sand fences: An environment-friendly technique to restore degraded coastal dunes

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    of prevailing winds (Matias et al. 2005). Our observations show that sand gets deposited 2 to 6 m downwind behind artificial barriers lying on the beach. A series of fences can therefore intercept wind-blown sand over a considerable area along the frontal beach..., but fashioned artificially; (e) Restoration of coastal dunes can be adopted wherever these features are damaged due to natural processes or human interference. Acknowledgements: The author is grateful to the Director, NIO, Goa, for permission to publish...

  7. Properties of body composition of female representatives of the Polish national fencing team - the sabre event.

    Science.gov (United States)

    Jagiełło, Władysław; Marina, Jagiełło; Maciej, Kalina Roman; Jan, Barczyński Bartłomiej; Artur, Litwiniuk; Jarosław, Klimczak

    2017-12-01

    Fencing is a combat sport whose form of direct confrontation involves hitting the opponent with a weapon. The purpose of the study was to determine the properties of body composition of female representatives of the Polish national fencing team. The study involved 11 female athletes of the Polish national fencing team. Their age was 16-22 years (19±2.32), body weight 52-78 kg (59.7±7.4), body height 158-183 cm (167.46±6.10) and the training experience 7.64±3.47 years. The reference group consisted of 153 students of Warsaw University of Technology (Poland). Twenty basic somatic characteristics were measured. The following indices were calculated: slenderness, Rohrer's, BMI, Manouvrier's, and pelvic-shoulder indices. Density of the body, total body fat, active tissue, the overall profile of body composition and internal proportions of the body were determined. Analysis of internal proportions of factors of the athletes' body composition revealed significant differences in particular groups of features. The total size of the athletes' bodies is due to less-than-average magnitude of the length and stoutness characteristics and a high magnitude of adiposity (M = 0.63) in the Polish female national team of fencers (sabre) calculated from the normalized values for the control group. The proportions of features within the analysed factors revealed a significant advantage of the length of the upper extremity over the lower one and a distinct advantage of forearm musculature. The specific profile of body composition of female athletes practising sabre fencing is most likely due to long-term effects of training as well as the system of selection of persons with specific somatic prerequisites developed in the course of many years of training practice.

  8. Struggling and Seeking for Identity-The Plight of the Protagonists in Fences

    Institute of Scientific and Technical Information of China (English)

    张晨虹; 刘翀

    2013-01-01

    The characters in August Wilson’s play Fences all suffer from great pain as African American in 50s society in U. S.. Father, mother and son exert their efforts struggling in both family life and social racism. The source of their survival plight, to great extent, lies in the confusion of identity. This paper explores the struggling and seeking of the characters from both interior and exterior world.

  9. Environmental Assessment for the Air Force Research Laboratory Security Fence Project, Edwards Air Force Base, California

    Science.gov (United States)

    2012-11-26

    Pleistocene/Early-Holocene Prehistory (12,000 to 7,000 BP). The Lake Mojave Period in the southwestern Great Basin comprises a regional manifestation...adaptive patterns with focal exploitation of such habitats (Tetra Tech 2010). Middle-Holocene Prehistory (8,000 to 4,000 BP). Succeeding Lake Mojave in the...Security Fence at Edwards Air Force Base, California Late Holocene Prehistory (4,000 to Contact). With return to more “favorable” environmental

  10. IB-LBM simulation on blood cell sorting with a micro-fence structure.

    Science.gov (United States)

    Wei, Qiang; Xu, Yuan-Qing; Tian, Fang-bao; Gao, Tian-xin; Tang, Xiao-ying; Zu, Wen-Hong

    2014-01-01

    A size-based blood cell sorting model with a micro-fence structure is proposed in the frame of immersed boundary and lattice Boltzmann method (IB-LBM). The fluid dynamics is obtained by solving the discrete lattice Boltzmann equation, and the cells motion and deformation are handled by the immersed boundary method. A micro-fence consists of two parallel slope post rows which are adopted to separate red blood cells (RBCs) from white blood cells (WBCs), in which the cells to be separated are transported one after another by the flow into the passageway between the two post rows. Effected by the cross flow, RBCs are schemed to get through the pores of the nether post row since they are smaller and more deformable compared with WBCs. WBCs are required to move along the nether post row till they get out the micro-fence. Simulation results indicate that for a fix width of pores, the slope angle of the post row plays an important role in cell sorting. The cells mixture can not be separated properly in a small slope angle, while obvious blockages by WBCs will take place to disturb the continuous cell sorting in a big slope angle. As an optimal result, an adaptive slope angle is found to sort RBCs form WBCs correctly and continuously.

  11. Fencing as a Part of the Urban Context of the District Blasewitz in Dresden

    Directory of Open Access Journals (Sweden)

    Anastasia Potapova

    2013-05-01

    Full Text Available Every city has its unique urban context including the objects that form the historical environment of the city; the material elements represented by buildings, constructions, sculptural and architectural forms, elements of spatial surroundings of monuments and terraced houses; the atmosphere, the landscape elements, and the visage as an element expressing the real nature of the visual object, that is the city space (the open space “enclosed” by material elements.The city of Dresden is not an exception. In its district Blasewitz, one of the most important aspects of urban context is expressed by the fences of the Gründer Epoch. These pompous and fine constructions separating the street space from the park villas have remained since the middle of the XIX century.The article explores the origin of villas as an urban ensemble of the Italian architecture, the development of this type of architecture in the 18-19th centuries and the methods of preservation of all the elements of this structure, including fences. It describes the fences remained in the district Blasewitz and their unique features.

  12. Semi-automated camera trap image processing for the detection of ungulate fence crossing events.

    Science.gov (United States)

    Janzen, Michael; Visser, Kaitlyn; Visscher, Darcy; MacLeod, Ian; Vujnovic, Dragomir; Vujnovic, Ksenija

    2017-09-27

    Remote cameras are an increasingly important tool for ecological research. While remote camera traps collect field data with minimal human attention, the images they collect require post-processing and characterization before it can be ecologically and statistically analyzed, requiring the input of substantial time and money from researchers. The need for post-processing is due, in part, to a high incidence of non-target images. We developed a stand-alone semi-automated computer program to aid in image processing, categorization, and data reduction by employing background subtraction and histogram rules. Unlike previous work that uses video as input, our program uses still camera trap images. The program was developed for an ungulate fence crossing project and tested against an image dataset which had been previously processed by a human operator. Our program placed images into categories representing the confidence of a particular sequence of images containing a fence crossing event. This resulted in a reduction of 54.8% of images that required further human operator characterization while retaining 72.6% of the known fence crossing events. This program can provide researchers using remote camera data the ability to reduce the time and cost required for image post-processing and characterization. Further, we discuss how this procedure might be generalized to situations not specifically related to animal use of linear features.

  13. Intelligent Machine Vision for Automated Fence Intruder Detection Using Self-organizing Map

    Directory of Open Access Journals (Sweden)

    Veldin A. Talorete Jr.

    2017-03-01

    Full Text Available This paper presents an intelligent machine vision for automated fence intruder detection. A series of still captured images that contain fence events using Internet Protocol cameras was used as input data to the system. Two classifiers were used; the first is to classify human posture and the second one will classify intruder location. The system classifiers were implemented using Self-Organizing Map after the implementation of several image segmentation processes. The human posture classifier is in charge of classifying the detected subject’s posture patterns from subject’s silhouette. Moreover, the Intruder Localization Classifier is in charge of classifying the detected pattern’s location classifier will estimate the location of the intruder with respect to the fence using geometric feature from images as inputs. The system is capable of activating the alarm, display the actual image and depict the location of the intruder when an intruder is detected. In detecting intruder posture, the system’s success rate of 88%. Overall system accuracy for day-time intruder localization is 83% and an accuracy of 88% for night-time intruder localization

  14. Advantages in exploring a new environment with the left eye in lizards.

    Science.gov (United States)

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-07-01

    Lizards (Podarcis muralis) preferentially use the left eye during spatial exploration in a binocular condition. Here we allowed 44 adult wild lizards to explore an unknown maze for 20 min under a temporary monocular condition whilst recording their movements, particularly the direction of turns made whilst walking within the maze. Lizards with a patch on their right eye, i.e. using their left eye to monitor the environment, moved faster than lizards with a patch on their left eye when turning both leftward and rightward in a T-cross. Hence, right eye-patched lizards were faster than left eye-patched lizards also in turning right, although their right eye was covered. Thus, lizards that could use the left eye/right hemisphere to attend spatial cues appeared to have more control and to be more prompt in exploring the maze. In addition, female lizards with their left eye covered stopped very frequently when they reached crosses, showing a high level of indecision. Results confirm that P. muralis lizards using their left eye only in exploring a new environment react faster and more efficiently than those using the right eye only in exploration. Hence lateralisation of spatial stimuli mediated by the left eye/right hemisphere could provide an advantage to this species. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Partial characterization of new adenoviruses found in lizards.

    Science.gov (United States)

    Ball, Inna; Behncke, Helge; Schmidt, Volker; Geflügel, F T A; Papp, Tibor; Stöhr, Anke C; Marschang, Rachel E

    2014-06-01

    In the years 2011-2012, a consensus nested polymerase chain reaction was used for the detection of adenovirus (AdV) infection in reptiles. During this screening, three new AdVs were detected. One of these viruses was detected in three lizards from a group of green striped tree dragons (Japalura splendida). Another was detected in a green anole (Anolis carolinensis). A third virus was detected in a Jackson's chameleon (Chamaeleo jacksonii). Analysis of a portion of the DNA-dependent DNA polymerase genes of each of these viruses revealed that they all were different from one another and from all previously described reptilian AdVs. Phylogenetic analysis of the partial DNA polymerase gene sequence showed that all newly detected viruses clustered within the genus Atadenovirus. This is the first description of AdVs in these lizard species.

  16. Colorful displays signal male quality in a tropical anole lizard

    Science.gov (United States)

    Cook, Ellee G.; Murphy, Troy G.; Johnson, Michele A.

    2013-10-01

    Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized individuals invest less in both ornamental color and behavioral display of that color. Because the two components of the signal simultaneously provide information on male quality, this study provides novel support for the long-standing hypothesis that colorful traits may function as social or sexual signals in reptiles.

  17. Unidirectional pulmonary airflow patterns in the savannah monitor lizard.

    Science.gov (United States)

    Schachner, Emma R; Cieri, Robert L; Butler, James P; Farmer, C G

    2014-02-20

    The unidirectional airflow patterns in the lungs of birds have long been considered a unique and specialized trait associated with the oxygen demands of flying, their endothermic metabolism and unusual pulmonary architecture. However, the discovery of similar flow patterns in the lungs of crocodilians indicates that this character is probably ancestral for all archosaurs--the group that includes extant birds and crocodilians as well as their extinct relatives, such as pterosaurs and dinosaurs. Unidirectional flow in birds results from aerodynamic valves, rather than from sphincters or other physical mechanisms, and similar aerodynamic valves seem to be present in crocodilians. The anatomical and developmental similarities in the primary and secondary bronchi of birds and crocodilians suggest that these structures and airflow patterns may be homologous. The origin of this pattern is at least as old as the split between crocodilians and birds, which occurred in the Triassic period. Alternatively, this pattern of flow may be even older; this hypothesis can be tested by investigating patterns of airflow in members of the outgroup to birds and crocodilians, the Lepidosauromorpha (tuatara, lizards and snakes). Here we demonstrate region-specific unidirectional airflow in the lungs of the savannah monitor lizard (Varanus exanthematicus). The presence of unidirectional flow in the lungs of V. exanthematicus thus gives rise to two possible evolutionary scenarios: either unidirectional airflow evolved independently in archosaurs and monitor lizards, or these flow patterns are homologous in archosaurs and V. exanthematicus, having evolved only once in ancestral diapsids (the clade encompassing snakes, lizards, crocodilians and birds). If unidirectional airflow is plesiomorphic for Diapsida, this respiratory character can be reconstructed for extinct diapsids, and evolved in a small ectothermic tetrapod during the Palaeozoic era at least a hundred million years before the

  18. Isoniazid-Associated Uric Acid Retention in the Lizard, Uromastix ...

    African Journals Online (AJOL)

    Reduction in uric acid excretion was observed following oral administration of 0.06 mg isoniazid per day for 5, 10 and 15 days to three groups of Uromastix hardwickii lizards. The rise of serum uric acid levels in the treated groups was 60 per cent higher on day 5, and about 4 and 5 times greater than in control groups on day ...

  19. “Sexual” behavior in parthenogenetic lizards (Cnemidophorus)

    OpenAIRE

    Crews, David; Fitzgerald, Kevin T.

    1980-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Basic data on the behavior of parthenogens are lacking, however. We have discovered, from observations of captive Cnemidophorus uniparens, C. velox, and C. tesselatus, behavior patterns remarkably similar to the courtship and copulatory behavior of closely related sexual species. Briefly, in separately housed pairs, one lizard was repeatedly seen to mount and ride its cagema...

  20. The auditory brainstem response in two lizard species.

    Science.gov (United States)

    Brittan-Powell, Elizabeth F; Christensen-Dalsgaard, Jakob; Tang, Yezhong; Carr, Catherine; Dooling, Robert J

    2010-08-01

    Although lizards have highly sensitive ears, it is difficult to condition them to sound, making standard psychophysical assays of hearing sensitivity impractical. This paper describes non-invasive measurements of the auditory brainstem response (ABR) in both Tokay geckos (Gekko gecko; nocturnal animals, known for their loud vocalizations) and the green anole (Anolis carolinensis, diurnal, non-vocal animals). Hearing sensitivity was measured in 5 geckos and 7 anoles. The lizards were sedated with isoflurane, and ABRs were measured at levels of 1 and 3% isoflurane. The typical ABR waveform in response to click stimulation showed one prominent and several smaller peaks occurring within 10 ms of the stimulus onset. ABRs to brief tone bursts revealed that geckos and anoles were most sensitive between 1.6-2 kHz and had similar hearing sensitivity up to about 5 kHz (thresholds typically 20-50 dB SPL). Above 5 kHz, however, anoles were more than 20 dB more sensitive than geckos and showed a wider range of sensitivity (1-7 kHz). Generally, thresholds from ABR audiograms were comparable to those of small birds. Best hearing sensitivity, however, extended over a larger frequency range in lizards than in most bird species.

  1. Evolution of extreme body size disparity in monitor lizards (Varanus).

    Science.gov (United States)

    Collar, David C; Schulte, James A; Losos, Jonathan B

    2011-09-01

    Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards. © 2011 The Author(s).

  2. The usefulness of mesocosms for ecotoxicity testing with lacertid lizards

    Directory of Open Access Journals (Sweden)

    Maria José Amaral

    2012-12-01

    Full Text Available Mesocosms (i.e., outdoor, man-made representations of natural ecosystems have seldom been used to study the impact of contaminants on terrestrial ecosystems. However, mesocosms can be a useful tool to provide a link between field and laboratory studies. We exposed juvenile lacertid lizards for a period of over one year to pesticides (herbicides and insecticides in mesocosm enclosures with the intention of validating field observations obtained in a previous study that examined the effects of corn pesticides in Podarcis bocagei. Our treatments replicated field conditions and consisted of a control, an herbicides only treatment (alachlor, terbuthylazine, mesotrione and glyphosate and an herbicides and insecticide treatment (including chlorpyrifos. We used a multi-biomarker approach that examined parameters at an individual and sub-individual level, including growth, locomotor performance, standard metabolic rate, biomarkers of oxidative stress, esterases and liver histopathologies. Although mortality over the course of the exposures was high (over 60%, surviving individuals prospered relatively well in the mesocosms and displayed a broad range of natural behaviours. The low numbers of replicate animals compromised many of the statistical comparisons, but in general, surviving lizards exposed to pesticides in mesocosm enclosures for over one year, thrived, and displayed few effects of pesticide exposure. Despite the difficulties, this work acts as an important stepping-stone for future ecotoxicology studies using lizards.

  3. Remote sensing as a tool to analyse lizards behaviour

    Science.gov (United States)

    Dos Santos, Remi; Teodoro, Ana C.; Carretero, Miguel; Sillero, Neftalí

    2016-10-01

    Although the spatial context is expected to be a major influence in the interactions among organisms and their environment, it is commonly ignored in ecological studies. This study is part of an investigation on home ranges and their influence in the escape behaviour of Iberian lizards. Fieldwork was conducted inside a 400 m2 mesocosm, using three acclimatized adult male individuals. In order to perform analyses at this local scale, tools with high spatial accuracy are needed. A total of 3016 GPS points were recorded and processed into a Digital Elevation Model (DEM), with a pixel resolution of 2 cm. Then, 1156 aerial photos were taken and processed to create an orthophoto. A refuge map, containing possible locations for retreats was generated with supervised image classification algorithms, obtaining four classes (refuges, vegetation, bare soil and organic soil). Furthermore, 50 data-loggers were randomly placed, recording evenly through the area temperature and humidity every 15'. After a month of recording, all environmental variables were interpolated using Kriging. The study area presented an irregular elevation. The humidity varied according to the topography and the temperature presented a West-East pattern. Both variables are of paramount importance for lizard activity and performance. In a predation risk scenario, a lizard located in a temperature close to its thermal optimum will be able to escape more efficiently. Integration of such ecologically relevant elements in a spatial context exemplifies how remote sensing tools can contribute to improve inference in behavioural ecology.

  4. Polyandry in dragon lizards: inbred paternal genotypes sire fewer offspring

    Science.gov (United States)

    Frère, Celine H; Chandrasoma, Dani; Whiting, Martin J

    2015-01-01

    Multiple mating in female animals is something of a paradox because it can either be risky (e.g., higher probability of disease transmission, social costs) or provide substantial fitness benefits (e.g., genetic bet hedging whereby the likelihood of reproductive failure is lowered). The genetic relatedness of parental units, particularly in lizards, has rarely been studied in the wild. Here, we examined levels of multiple paternity in Australia's largest agamid lizard, the eastern water dragon (Intellagama lesueurii), and determined whether male reproductive success is best explained by its heterozygosity coefficient or the extent to which it is related to the mother. Female polyandry was the norm: 2/22 clutches (9.2%) were sired by three or more fathers, 17/22 (77.2%) were sired by two fathers, and only 3/22 (13.6%) clutches were sired by one father. Moreover, we reconstructed the paternal genotypes for 18 known mother–offspring clutches and found no evidence that females were favoring less related males or that less related males had higher fitness. However, males with greater heterozygosity sired more offspring. While the postcopulatory mechanisms underlying this pattern are not understood, female water dragons likely represent another example of reproduction through cryptic means (sperm selection/sperm competition) in a lizard, and through which they may ameliorate the effects of male-driven precopulatory sexual selection. PMID:25937911

  5. Telling tails: selective pressures acting on investment in lizard tails.

    Science.gov (United States)

    Fleming, Patricia A; Valentine, Leonie E; Bateman, Philip W

    2013-01-01

    Caudal autotomy is a common defense mechanism in lizards, where the animal may lose part or all of its tail to escape entrapment. Lizards show an immense variety in the degree of investment in a tail (i.e., length) across species, with tails of some species up to three or four times body length (snout-vent length [SVL]). Additionally, body size and form also vary dramatically, including variation in leg development and robustness and length of the body and tail. Autotomy is therefore likely to have fundamentally different effects on the overall body form and function in different species, which may be reflected directly in the incidence of lost/regenerating tails within populations or, over a longer period, in terms of relative tail length for different species. We recorded data (literature, museum specimens, field data) for relative tail length (n=350 species) and the incidence of lost/regenerating tails (n=246 species). We compared these (taking phylogeny into account) with intrinsic factors that have been proposed to influence selective pressures acting on caudal autotomy, including body form (robustness, body length, leg development, and tail specialization) and ecology (foraging behavior, physical and temporal niches), in an attempt to identify patterns that might reflect adaptive responses to these different factors. More gracile species have relatively longer tails (all 350 spp., P lost/regenerating tails for nocturnal lizards (all 246 spp., P pressure.

  6. Eating lizards: a millenary habit evidenced by Paleoparasitology

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    Sianto Luciana

    2012-10-01

    Full Text Available Abstract Background Analyses of coprolites have contributed to the knowledge of diet as well as infectious diseases in ancient populations. Results of paleoparasitological studies showed that prehistoric groups were exposed to spurious and zoonotic parasites, especially food-related. Here we report the findings of a paleoparasitological study carried out in remote regions of Brazil’s Northeast. Findings Eggs of Pharyngodonidae (Nematoda, Oxyuroidea, a family of parasites of lizards and amphibians, were found in four human coprolites collected from three archaeological sites. In one of these, lizard scales were also found. Conclusions Through the finding of eggs of Pharyngodonidae in human coprolites and reptile scales in one of these, we have provided evidence that humans have consumed reptiles at least 10,000 years ago. This food habit persists to modern times in remote regions of Brazil’s Northeast. Although Pharyngodonidae species are not known to infect humans, the consumption of raw or undercooked meat from lizards and other reptiles may have led to transmission of a wide range of zoonotic agents to humans in the past.

  7. The first iguanian lizard from the Mesozoic of Africa

    Science.gov (United States)

    Daza, Juan D.; Simões, Tiago R.; Rage, Jean Claude

    2016-01-01

    The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous. However, the biogeographic history and early evolution of one of its most diverse and peculiar clades (acrodontans) remain poorly known. Here, we present the first Mesozoic acrodontan from Africa, which also represents the oldest iguanian lizard from that continent. The new taxon comes from the Kem Kem Beds in Morocco (Cenomanian, Late Cretaceous) and is based on a partial lower jaw. The new taxon presents a number of features that are found only among acrodontan lizards and shares greatest similarities with uromastycines, specifically. In a combined evidence phylogenetic dataset comprehensive of all major acrodontan lineages using multiple tree inference methods (traditional and implied weighting maximum-parsimony, and Bayesian inference), we found support for the placement of the new species within uromastycines, along with Gueragama sulamericana (Late Cretaceous of Brazil). The new fossil supports the previously hypothesized widespread geographical distribution of acrodontans in Gondwana during the Mesozoic. Additionally, it provides the first fossil evidence of uromastycines in the Cretaceous, and the ancestry of acrodontan iguanians in Africa. PMID:27703708

  8. Species composition, richness and nestedness of lizard assemblages from Restinga habitats along the brazilian coast

    Directory of Open Access Journals (Sweden)

    CFD. Rocha

    Full Text Available Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the “Nestedness Temperature Calculator” to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island. Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P <0.00001; 5000 randomisations; randomisation temperature = 51.45° ± 7.18° SD, indicating that lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.

  9. Experimental study on effects of inlet boundary layer thickness and boundary layer fence in a turbine cascade

    International Nuclear Information System (INIS)

    Jun, Y. M.; Chung, J. T.

    2000-01-01

    The working fluid from the combustor to the turbine stage of a gas turbine makes various boundary layer thickness. Since the inlet boundary layer thickness is one of the important factors that affect the turbine efficiency, It is necessary to investigate secondary flow and loss with various boundary layer thickness conditions. In the present study, the effect of various inlet boundary layer thickness on secondary flow and loss and the proper height of the boundary layer fences for various boundary layer thickness were investigated. Measurements of secondary flow velocity and total pressure loss within and downstream of the passage were taken under 5 boundary layer thickness conditions, 16, 36, 52, 69, 110mm. It was found that total pressure loss and secondary flow areas were increased with increase of thickness but they were maintained almost at the same position. At the following research about the boundary layer fences, 1/6, 1/3, 1/2 of each inlet boundary layer thickness and 12mm were used as the fence heights. As a result, it was observed that the proper height of the fences was generally constant since the passage vortex remained almost at the same position. Therefore once the geometry of a cascade is decided, the location of the passage vortex and the proper fence height are appeared to be determined at the same time. When the inlet boundary layer thickness is relatively small, the loss caused by the proper fence becomes bigger than end wall loss so that it dominates secondary loss. In these cases the proper fence height is decided not by the cascade geometry but by the inlet boundary layer thickness as previous investigations

  10. Condition-dependent chemosignals in reproductive behavior of lizards.

    Science.gov (United States)

    Martín, José; López, Pilar

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Many lizards have diverse glands that produce chemosignals used in intraspecific communication and that can have reproductive consequences. For example, information in chemosignals of male lizards can be used in intrasexual competition to identify and assess the fighting potential or dominance status of rival males either indirectly through territorial scent-marks or during agonistic encounters. Moreover, females of several lizard species "prefer" to establish or spend more time on areas scent-marked by males with compounds signaling a better health or body condition or a higher genetic compatibility, which can have consequences for their mating success and inter-sexual selection processes. We review here recent studies that suggest that the information content of chemosignals of lizards may be reliable because several physiological and endocrine processes would regulate the proportions of chemical compounds available for gland secretions. Because chemosignals are produced by the organism or come from the diet, they should reflect physiological changes, such as different hormonal levels (e.g. testosterone or corticosterone) or different health states (e.g. parasitic infections, immune response), and reflect the quality of the diet of an individual. More importantly, some compounds that may function as chemosignals also have other important functions in the organism (e.g. as antioxidants or regulating the immune system), so there could be trade-offs between allocating these compounds to attending physiological needs or to produce costly sexual "chemical ornaments". All these factors may contribute to maintain chemosignals as condition-dependent sexual signals, which can inform conspecifics on the characteristics and state of the sender and allow making behavioral decisions with reproductive consequences. To understand the evolution of chemical secretions of lizards as sexual signals and their

  11. Preliminary assessment of changes in a lizard assemblage at an ecotone in southeastern Arizona

    Science.gov (United States)

    Lawrence L. C. Jones

    2013-01-01

    The Madrean Archipelago and its associated valleys have the highest diversity of lizards in the United States. This is due to a convergence of ecoregions in an area that provides excellent environmental conditions for life history needs of terrestrial ectotherms. The study area, near Safford, Arizona, is known to have about 20 species of sympatric lizards, although...

  12. Looking at a predator with the left or right eye: asymmetry of response in lizards.

    Science.gov (United States)

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-01-01

    Studies carried out with the common wall lizard (Podarcis muralis) revealed preferential use of the left eye during responses to predatory threat in laboratory settings and in the wild. Here we tested lizards under monocular conditions of vision, using temporary eye-patching. Lizards were facing a (simulated) predatory threat laterally, from the side of the non-patched eye. Results showed that lizards with the left eye uncovered during predatory threat used the left eye to monitor the predator, whereas lizards with the right eye uncovered nonetheless tried to use the covered left eye. Moreover, lizards frequently tried to change the eye exposition, making a body C-bend behaviour. Right-eyed lizards showed more frequent and faster C-bending responses than left-eyed lizards, trying to monitor the predator with the left eye even though it was patched. Results fit with asymmetries in spontaneous eye use observed in laboratory conditions and in the wild in this species, confirming that structures located on the right side of the brain (mainly served by the left eye) predominantly attend to predatory threat.

  13. Predicting micro thermal habitat of lizards in a dynamic thermal environment

    NARCIS (Netherlands)

    Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Toxopeus, A.G.; Bian, B.M.; Liu, Y.

    2012-01-01

    Understanding behavioural thermoregulation and its consequences is a central topic in ecology. In this study, a spatial explicit model was developed to simulate the movement and thermal habitat use of lizards in a controlled environment. The model incorporates a lizard's transient body temperatures

  14. Intraspecific competition and high food availability are associated with insular gigantism in a lizard.

    Science.gov (United States)

    Pafilis, Panayiotis; Meiri, Shai; Foufopoulos, Johannes; Valakos, Efstratios

    2009-09-01

    Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards (Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have fewer predators and competitors than on Skyros but differ in the numbers of nesting seabirds. We predicted the following: (1) the presence of breeding seabirds (providing nutrients) will increase lizard population densities; (2) dense lizard populations will experience stronger intraspecific competition; and (3) such aggression, will be associated with larger average body size. We found a positive correlation between seabird and lizard densities. Cannibalism and tail injuries were considerably higher in dense populations. Increases in cannibalism and tail loss were associated with large body sizes. Adult cannibalism on juveniles may select for rapid growth, fuelled by high food abundance, setting thus the stage for the evolution of gigantism.

  15. Landscape structure and live fences in Andes Colombian agrosystems: upper basin of the Cane-Iguaque River.

    Science.gov (United States)

    Otero, Javier; Onaindia, Miren

    2009-12-01

    Changes in land use have generated a new landscape configuration in the Andino orobiome (mountain range) of the tropical Andes, resulting in a mosaic of cultivation and pastures interrupted by small fragments of forest and live fences. This has resulted in an ongoing decrease in the biodiversity of this biome. In the upper basin of the Cane-Iguaque River (Villa de Levya-Boyacá, Colombia), located 2,600-3,000 m above the Cordillera Oriental, over three time periods in 1960, 1984, and 2004, we characterized the structure, patterns, and evolution of the overall landscape and of the live fences (used as tools in biodiversity conservation and considered to be desirable alternatives to nonlive fences in farming production systems) within an agricultural landscape. To do this, we interpreted high-resolution satellite images using a landscape ecology approach and applied landscape map metrics. We found that the natural forests have been transformed by pastures and cultivation, and that although live fences cover only a small portion of the total landscape (4.6%), they have an important effect on landscape structure and biodiversity. There has been an increase in live fences, especially between 1960 and 1984, as well as an increase in their density. However, there has been a reduction in the average length of live fences over the periods that we studied. This could be due in part to changes in the types of agricultural products that have been cultivated in recent years, with an increase in potatoes and a decrease in other vegetables, and also by resource extraction of timber and fuel wood. In the studied area, agricultural production was sustained while biodiversity conservation was improved by the use of live fences. Therefore, live fences should be considered not only as part of an agriculturally productive area, but also as an important element of a multi-functional landscape that contributes to the maintenance of biodiversity and provides resources of economic and

  16. Perch-height specific predation on tropical lizard clay models: implications for habitat selection in mainland neotropical lizards

    Directory of Open Access Journals (Sweden)

    John E Steffen

    2009-09-01

    Full Text Available Predation has been hypothesized to be a strong selective force structuring communities of tropical lizards. Comparisons of perch height and size-based predation frequencies can provide a unique window into understanding how predation might shape habitat selection and morphological patterns in lizards, especially anoles. Here i use plasticine clay models, placed on the trunks of trees and suspended in the canopy to show that predation frequency on clay models differs primarily according to habitat (canopy vs. trunk-ground, but not according to size. These data are discussed in light of observed lizard abundances in the lowland forests of Costa Rica, and are presented as partial explanation for why fewer lizards are found in tree canopies, and more lizards are found on ground-trunk habitats. Rev. Biol. Trop. 57 (3: 859-864. Epub 2009 September 30.Existe la hipótesis de que la depredación es una fuerte fuerza selectiva que estructura las comunidades de lagartijas tropicales. Las comparaciones de las frecuencias de altura de la percha y de depredación con base en el tamaño pueden proveer una ventana única en el entendimiento de cómo la depredación podría moldear la selección del hábitat y los patrones morfológicos en las lagartijas, especialmente anoles. En este estudio uso modelos de plasticina, ubicados en troncos de árboles y suspendidos en el dosel para mostrar que la frecuencia de depredación en los modelos de plasticina difiere primariamente según el hábitat (dosel vs. tronco-suelo pero no según el tamaño. Estos datos se discuten a la luz de las abundancias de lagartijas observadas en los bosques de bajura de Costa Rica, y se presentan como una explicación parcial a porqué menos lagartijas se encuentran en los doseles, y más lagartijas se encuentran en los hábitats suelo-tronco.

  17. Immunity of the Fe-N-C catalysts to electrolyte adsorption: phosphate but not perchloric anions

    DEFF Research Database (Denmark)

    Hu, Yang; Jensen, Jens Oluf; Pan, Chao

    2018-01-01

    often carried out, like for Pt-based catalysts, in dilute perchloric acid by assuming its non-adsorbing nature on the active sites. The assumption is however not true. In this work, a typical Fe-N-C catalyst was first synthesized by high-pressure pyrolysis in the presence of carbon support...... and thoroughly characterized in terms of morphology, structure and active site distribution. The subsequent electrochemical characterization of the catalyst shows strong adsorption and poisoning effect of, in addition to the known Cl-, perchloric anions on the oxygen reduction reaction (ORR) activity...

  18. Unraveling the Nature of Sites Active toward Hydrogen Peroxide Reduction in Fe?N?C Catalysts

    OpenAIRE

    Choi, Chang Hyuck; Choi, Won Seok; Kasian, Olga; Mechler, Anna K.; Sougrati, Moulay Tahar; Br?ller, Sebastian; Strickland, Kara; Jia, Qingying; Mukerjee, Sanjeev; Mayrhofer, Karl J. J.; Jaouen, Fr?d?ric

    2017-01-01

    Abstract Fe?N?C catalysts with high O2 reduction performance are crucial for displacing Pt in low?temperature fuel cells. However, insufficient understanding of which reaction steps are catalyzed by what sites limits their progress. The nature of sites were investigated that are active toward H2O2 reduction, a key intermediate during indirect O2 reduction and a source of deactivation in fuel cells. Catalysts comprising different relative contents of FeN x C y moieties and Fe particles encapsu...

  19. DEVELOPMENTS IN MONITORING RANGELANDS USING REMOTELY-SENSED CROSS-FENCE COMPARISONS

    Directory of Open Access Journals (Sweden)

    A. D. Kilpatrick

    2012-07-01

    Full Text Available This paper presents a new method for the use of earth-observation images to assess relative land condition over broad regions, using a cross-fence comparison methodology. It controls for natural spatial and temporal variables (e.g. rainfall, temperature soils, ecosystem so that we can objectively monitor rangelands and other areas for the effects of management. The method has been tested with small and large scale theoretical models, as well as a case study in South Australian rangelands. This method can also be applied in other systems and experiments such as field trials of crop varieties as a robust spatial statistic.

  20. Species composition, richness and nestedness of lizard assemblages from Restinga habitats along the brazilian coast.

    Science.gov (United States)

    Rocha, C F D; Vrcibradic, D; Kiefer, M C; Menezes, V A; Fontes, A F; Hatano, F H; Galdino, C A B; Bergallo, H G; Van Sluys, M

    2014-05-01

    Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia) and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the "Nestedness Temperature Calculator" to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species) whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island). Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.

  1. Thermal dependence of sprint performance in the lizard Psammodromus algirus along a 2200-meter elevational gradient: Cold-habitat lizards do not perform better at low temperatures.

    Science.gov (United States)

    Zamora-Camacho, Francisco Javier; Rubiño-Hispán, María Virtudes; Reguera, Senda; Moreno-Rueda, Gregorio

    2015-08-01

    Sprint speed has a capital relevance in most animals' fitness, mainly for fleeing from predators. Sprint performance is maximal within a certain range of body temperatures in ectotherms, whose thermal upkeep relies on exogenous thermal sources. Ectotherms can respond to diverse thermal environments either by shifting their thermal preferences or maintaining them through different adaptive mechanisms. Here, we tested whether maximum sprint speed of a lizard that shows conservative thermal ecology along a 2200-meter elevational gradient differs with body temperature in lizards from different elevations. Lizards ran faster at optimum than at suboptimum body temperature. Notably, high-elevation lizards were not faster than mid- and low-elevation lizards at suboptimum body temperature, despite their low-quality thermal environment. This result suggests that both preferred body temperature and thermal dependence of speed performance are co-adapted along the elevational gradient. High-elevation lizards display a number of thermoregulatory strategies that allow them to achieve high optimum body temperatures in a low thermal-quality habitat and thus maximize speed performance. As for reproductive condition, we did not find any effect of it on sprint speed, or any significant interaction with elevation or body temperature. However, strikingly, gravid females were significantly slower than males and non-gravid females at suboptimum temperature, but performed similarly well at optimal temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. PRESERVATIVE TREATMENT OF Mimosa scabrella BENTH. AND Eucalyptus viminalis LAB. FENCE POSTS BY DIP-DIFFUSION METHOD

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2001-01-01

    Full Text Available This work aimed to compare the diffusion of CCB preservative in bracatinga (Mimosa scabrella Benth. and Eucalyptus viminalis Lab. round fence posts when exposed to dip-diffusion method. The pieces were submitted to the concentration of 2; 3.5 and 5% of active ingredients of “Osmose CCB” commercial preservative, during 2, 5 and 8 days. The penetration was analyzed in six positions in the pieces and the retention in three positions in the disks taken in ground contact area in the fence posts fitted out. The increase of treatment time and preservative concentration provided significant gains on penetration and retention of CCB for both tree species. In the work conditions, the eucalypt fence posts showed better response to the treatment.

  3. New properties of a fiber optic sensor in application of a composite fence for critical infrastructure protection

    Science.gov (United States)

    Zyczkowski, M.; Szustakowski, M.; Markowski, P.

    2015-09-01

    This paper presents a new solution of using the composite fence with a novel fiber optic modalmetric sensor integrated within its structure. The modalmetric sensor is based on changes in a transverse modal field which is generated at the output of a multimode fiber. By a spatial limitation of the transverse modal field observation to its fragment thereof, changes' transformation in the modal distribution into changes of the output signal amplitude is made. Due to a constant analysis of the structure output signal, detection of an external disorder is possible. Integration of optical fibers with the fence structure allows for an accurate reproduction of the fence movement onto the optical fiber by significantly improving sensitivity of the modalmetric fiber sensor structure.

  4. Body condition, diet and ecosystem function of red deer (Cervus elaphus in a fenced nature reserve

    Directory of Open Access Journals (Sweden)

    Camilla Fløjgaard

    2017-07-01

    Full Text Available Body condition, as a sign of animal welfare, is of management concern in rewilding projects where fenced animals are subject to winter starvation, which may conflict with animal welfare legislation. Investigating the relationship between body condition, age, sex, diet quality and diet composition is therefore relevant to increase understanding of herbivores' ecosystem function and to inform management. In this study, we focused on red deer, Cervus elaphus, in a fenced nature reserve in Denmark, where the deer are managed as ecosystem engineers to contribute to biodiversity conservation. We measured body mass and body size of 91 culled red deer, and determined diet composition using DNA metabarcoding and diet quality using fecal nitrogen on 246 fecal samples. We found that body condition was predicted by age and diet composition, but not diet quality. We also found that individuals of different body condition had different diets, i.e., the fecal samples of red deer in poorer body condition contained significantly more Ericaceae sequences than red deer in good body condition. This may imply that certain functions of red deer in ecosystems, such as regeneration of heather by grazing, may depend on variation in body condition within the population. Our findings call for the need to consider the consequences of management practices, including culling or supplemental feeding, on the outcomes of habitat restoration, and more broadly underline the importance of preserving the overall breath of herbivore ecosystem functions for effective biodiversity conservation.

  5. Mobile Fences: J.M. Coetzee’s Waiting for the Barbarians

    Directory of Open Access Journals (Sweden)

    Eleonora Pizzinat

    2011-05-01

    Full Text Available Fences usually enclose and separate, but they are also places of exchange neither inside nor outside. This concept is well represented in J.M. Coetzee’s Waiting for the Barbarians, because not only this novel is setted on the border between an undefined Empire and the barbarians’ lands, but it also plays with various declinations of the idea of limit and boundary. Through a reading which intends to highlight every kind of frame in the novel, it will emerge that no border is fixed and conclusive. Namely, in this book every real or metaphoric fence is called into question: the distinction between the duality of “us and them” is actually determined by the Empire’s walls which separate the inside from the outside in an arbitrary way; the magistrate (with the empathy he feels for the barbarian girl is inevitably caught in a double bind; and, according to Emmanuel Lévinas’ philosophy, the desire to understand otherness reveals its predatory intentions from a post-colonial point of view. It is not possible to delineate an ultimate bordeline, and it will emerge that instead of a binary logic there is a more fruitful way of thinking, a way based on frames, paradoxes and literary texts which cannot be read as flat mirroring devices.

  6. Has computational creativity successfully made it "Beyond the Fence" in musical theatre?

    Science.gov (United States)

    Jordanous, Anna

    2017-10-01

    A significant test for software is to task it with replicating human performance, as done recently with creative software and the commercial project Beyond the Fence (undertaken for a television documentary Computer Says Show). The remit of this project was to use computer software as much as possible to produce "the world's first computer-generated musical". Several creative systems were used to generate this musical, which was performed in London's West End in 2016. This paper considers the challenge of evaluating this project. Current computational creativity evaluation methods are ill-suited to evaluating projects that involve creative input from multiple systems and people. Following recent inspiration within computational creativity research from interaction design, here the DECIDE evaluation framework is applied to evaluate the Beyond the Fence project. Evaluation finds that the project was reasonably successful at achieving the task of using computational generation to produce a credible musical. Lessons have been learned for future computational creativity projects though, particularly for affording creative software more agency and enabling software to interact with other creative partners. Upon reflection, the DECIDE framework emerges as a useful evaluation "checklist" (if not a tangible operational methodology) for evaluating multiple creative systems participating in a creative task.

  7. Circadian rhythm of temperature selection in a nocturnal lizard.

    Science.gov (United States)

    Refinetti, R; Susalka, S J

    1997-08-01

    We recorded body temperature and locomotor activity of Tokay geckos (Gekko gecko) with free access to a heat source under a 14:10 light-dark cycle and in constant darkness. Under the light-dark cycle, the lizards selected higher temperatures during the light phase, when locomotor activity was less intense. Rhythmicity in temperature selection was transiently disrupted but later resumed when the animals were placed in constant darkness. These results demonstrate the existence of a circadian rhythm of temperature selection in nocturnal ectotherms and extend previous findings of a temporal mismatch between the rhythms of locomotor activity and temperature selection in nocturnal rodents.

  8. The blue lizard spandrel and the island syndrome.

    Science.gov (United States)

    Raia, Pasquale; Guarino, Fabio M; Turano, Mimmo; Polese, Gianluca; Rippa, Daniela; Carotenuto, Francesco; Monti, Daria M; Cardi, Manuela; Fulgione, Domenico

    2010-09-20

    Many small vertebrates on islands grow larger, mature later, lay smaller clutches/litters, and are less sexually dimorphic and aggressive than their mainland relatives. This set of observations is referred to as the 'Island Syndrome'. The syndrome is linked to high population density on islands. We predicted that when population density is low and/or fluctuating insular vertebrates may evolve correlated trait shifts running opposite to the Island Syndrome, which we collectively refer to as the 'reversed island syndrome' (RIS) hypothesis. On the proximate level, we hypothesized that RIS is caused by increased activity levels in melanocortin receptors. Melanocortins are postranslational products of the proopiomelanocortin gene, which controls pleiotropically pigmentation, aggressiveness, sexual activity, and food intake in vertebrates. We tested the RIS hypothesis performing a number of behavioral, genetic, and ontogenetic tests on a blue colored insular variant of the Italian Wall lizard Podarcis sicula, living on a small island off the Southern Italian coast. The population density of this blue-colored variant was generally low and highly fluctuating from one year to the next.In keeping with our predictions, insular lizards were more aggressive and sexually dimorphic than their mainland relatives. Insular males had wide, peramorphic heads. The growth rate of insular females was slower than growth rates of mainland individuals of both sexes, and of insular males. Consequently, size and shape dimorphism are higher on the Island. As predicted, melanocortin receptors were much more active in individuals of the insular population. Insular lizards have a higher food intake rate than mainland individuals, which is consistent with the increased activity of melanocortin receptors. This may be adaptive in an unpredictable environment such as Licosa Island. Insular lizards of both sexes spent less time basking than their mainland relatives. We suspect this is a by

  9. The blue lizard spandrel and the island syndrome

    Directory of Open Access Journals (Sweden)

    Monti Daria M

    2010-09-01

    Full Text Available Abstract Background Many small vertebrates on islands grow larger, mature later, lay smaller clutches/litters, and are less sexually dimorphic and aggressive than their mainland relatives. This set of observations is referred to as the 'Island Syndrome'. The syndrome is linked to high population density on islands. We predicted that when population density is low and/or fluctuating insular vertebrates may evolve correlated trait shifts running opposite to the Island Syndrome, which we collectively refer to as the 'reversed island syndrome' (RIS hypothesis. On the proximate level, we hypothesized that RIS is caused by increased activity levels in melanocortin receptors. Melanocortins are postranslational products of the proopiomelanocortin gene, which controls pleiotropically pigmentation, aggressiveness, sexual activity, and food intake in vertebrates. Results We tested the RIS hypothesis performing a number of behavioral, genetic, and ontogenetic tests on a blue colored insular variant of the Italian Wall lizard Podarcis sicula, living on a small island off the Southern Italian coast. The population density of this blue-colored variant was generally low and highly fluctuating from one year to the next. In keeping with our predictions, insular lizards were more aggressive and sexually dimorphic than their mainland relatives. Insular males had wide, peramorphic heads. The growth rate of insular females was slower than growth rates of mainland individuals of both sexes, and of insular males. Consequently, size and shape dimorphism are higher on the Island. As predicted, melanocortin receptors were much more active in individuals of the insular population. Insular lizards have a higher food intake rate than mainland individuals, which is consistent with the increased activity of melanocortin receptors. This may be adaptive in an unpredictable environment such as Licosa Island. Insular lizards of both sexes spent less time basking than their

  10. Does the Morphology of the Forelimb Flexor Muscles Differ Between Lizards Using Different Habitats?

    Science.gov (United States)

    Lowie, Aurélien; Herrel, Anthony; Abdala, Virginia; Manzano, Adriana S; Fabre, Anne-Claire

    2018-03-01

    Lizards are an interesting group to study how habitat use impacts the morphology of the forelimb because they occupy a great diversity of ecological niches. In this study, we specifically investigated whether habitat use impacts the morphology of the forelimb flexor muscles in lizards. To do so, we performed dissections and quantified the physiological cross sectional area (PCSA), the fiber length, and the mass of four flexor muscles in 21 different species of lizards. Our results show that only the PCSA of the m. flexor carpi radialis is different among lizards with different ecologies (arboreal versus non-arboreal). This difference disappeared, however, when taking phylogeny into account. Arboreal species have a higher m. flexor carpi radialis cross sectional area likely allowing them to flex the wrist more forcefully which may allow them climb and hold on to branches better. In contrast, other muscles are not different between arboreal and non-arboreal species. Further studies focusing on additional anatomical features of the lizard forelimb as well as studies documenting how lizards use the arboreal niche are needed to fully understand how an arboreal life style may constrain limb morphology in lizards. Anat Rec, 301:424-433, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  11. Using Snow Fences to Augument Fresh Water Supplies in Shallow Arctic Lakes

    Energy Technology Data Exchange (ETDEWEB)

    Stuefer, Svetlana

    2013-03-31

    This project was funded by the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to address environmental research questions specifically related to Alaska's oil and gas natural resources development. The focus of this project was on the environmental issues associated with allocation of water resources for construction of ice roads and ice pads. Earlier NETL projects showed that oil and gas exploration activities in the U.S. Arctic require large amounts of water for ice road and ice pad construction. Traditionally, lakes have been the source of freshwater for this purpose. The distinctive hydrological regime of northern lakes, caused by the presence of ice cover and permafrost, exerts influence on lake water availability in winter. Lakes are covered with ice from October to June, and there is often no water recharge of lakes until snowmelt in early June. After snowmelt, water volumes in the lakes decrease throughout the summer, when water loss due to evaporation is considerably greater than water gained from rainfall. This balance switches in August, when air temperature drops, evaporation decreases, and rain (or snow) is more likely to occur. Some of the summer surface storage deficit in the active layer and surface water bodies (lakes, ponds, wetlands) is recharged during this time. However, if the surface storage deficit is not replenished (for example, precipitation in the fall is low and near‐surface soils are dry), lake recharge is directly affected, and water availability for the following winter is reduced. In this study, we used snow fences to augment fresh water supplies in shallow arctic lakes despite unfavorable natural conditions. We implemented snow‐control practices to enhance snowdrift accumulation (greater snow water equivalent), which led to increased meltwater production and an extended melting season that resulted in lake recharge despite low precipitation during the years of the experiment. For three years (2009

  12. Comparison of the effectiveness of phalanges vs. humeri and femurs to estimate lizard age with skeletochronology

    International Nuclear Information System (INIS)

    Comas, M.; Reguera, S.; Zamora-Camacho, F.J.; Salvado, H.; Moreno-Rueda, G.

    2016-01-01

    Skeletochronology allows estimation of lizard age with a single capture (from a bone), making long–term monitoring unnecessary. Nevertheless, this method often involves the death of the animal to obtain the bone. We tested the reliability of skeletochronology of phalanges (which may be obtained without killing) by comparing the estimated age from femurs and humeri with the age estimated from phalanges. Our results show skeletochronology of phalanges is a reliable method to estimate age in lizards as cross–section readings from all bones studied presented a high correlation and repeatability regardless of the bone chosen. This approach provides an alternative to the killing of lizards for skeletochronology studies. (Author)

  13. Effects of asymmetry and learning on phonotaxis in a robot based on the lizard auditory system

    DEFF Research Database (Denmark)

    Zhang, L.; Hallam, J.; Christensen-Dalsgaard, J.

    2012-01-01

    Lizards have strong directional hearing across a broad band of frequencies. The directionality can be attributed to the acoustical properties of the ear, especially the strong acoustical coupling of the two eardrums. The peripheral auditory system of the lizard has previously been modeled...... and magnitude of their intrinsic bias. To attain effective directional hearing, the bias in the peripheral system should be compensated. In this article, with the peripheral models, we design a decision model and a behavior model, a virtual robot, to simulate the auditory system of the lizard in software...

  14. Comparison of the effectiveness of phalanges vs. humeri and femurs to estimate lizard age with skeletochronology

    Energy Technology Data Exchange (ETDEWEB)

    Comas, M.; Reguera, S.; Zamora-Camacho, F.J.; Salvado, H.; Moreno-Rueda, G.

    2016-07-01

    Skeletochronology allows estimation of lizard age with a single capture (from a bone), making long–term monitoring unnecessary. Nevertheless, this method often involves the death of the animal to obtain the bone. We tested the reliability of skeletochronology of phalanges (which may be obtained without killing) by comparing the estimated age from femurs and humeri with the age estimated from phalanges. Our results show skeletochronology of phalanges is a reliable method to estimate age in lizards as cross–section readings from all bones studied presented a high correlation and repeatability regardless of the bone chosen. This approach provides an alternative to the killing of lizards for skeletochronology studies. (Author)

  15. Chemical communication, sexual selection, and introgression in wall lizards.

    Science.gov (United States)

    MacGregor, Hannah E A; Lewandowsky, Rachel A M; d'Ettorre, Patrizia; Leroy, Chloé; Davies, Noel W; While, Geoffrey M; Uller, Tobias

    2017-10-01

    Divergence in communication systems should influence the likelihood that individuals from different lineages interbreed, and consequently shape the direction and rate of hybridization. Here, we studied the role of chemical communication in hybridization, and its contribution to asymmetric and sexually selected introgression between two lineages of the common wall lizard (Podarcis muralis). Males of the two lineages differed in the chemical composition of their femoral secretions. Chemical profiles provided information regarding male secondary sexual characters, but the associations were variable and inconsistent between lineages. In experimental contact zones, chemical composition was weakly associated with male reproductive success, and did not predict the likelihood of hybridization. Consistent with these results, introgression of chemical profiles in a natural hybrid zone resembled that of neutral nuclear genetic markers overall, but one compound in particular (tocopherol methyl ether) matched closely the introgression of visual sexual characters. These results imply that associations among male chemical profiles, sexual characters, and reproductive success largely reflect transient and environmentally driven effects, and that genetic divergence in chemical composition is largely neutral. We therefore suggest that femoral secretions in wall lizards primarily provide information about residency and individual identity rather than function as sexual signals. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  16. Extended molecular phylogenetics and revised systematics of Malagasy scincine lizards.

    Science.gov (United States)

    Erens, Jesse; Miralles, Aurélien; Glaw, Frank; Chatrou, Lars W; Vences, Miguel

    2017-02-01

    Among the endemic biota of Madagascar, skinks are a diverse radiation of lizards that exhibit a striking ecomorphological variation, and could provide an interesting system to study body-form evolution in squamate reptiles. We provide a new phylogenetic hypothesis for Malagasy skinks of the subfamily Scincinae based on an extended molecular dataset comprising 8060bp from three mitochondrial and nine nuclear loci. Our analysis also increases taxon sampling of the genus Amphiglossus by including 16 out of 25 nominal species. Additionally, we examined whether the molecular phylogenetic patterns coincide with morphological differentiation in the species currently assigned to this genus. Various methods of inference recover a mostly strongly supported phylogeny with three main clades of Amphiglossus. However, relationships among these three clades and the limb-reduced genera Grandidierina, Voeltzkowia and Pygomeles remain uncertain. Supported by a variety of morphological differences (predominantly related to the degree of body elongation), but considering the remaining phylogenetic uncertainty, we propose a redefinition of Amphiglossus into three different genera (Amphiglossus sensu stricto, Flexiseps new genus, and Brachyseps new genus) to remove the non-monophyly of Amphiglossus sensu lato and to facilitate future studies on this fascinating group of lizards. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. The conservation status of the Saldanha-Langebaan lizard fauna

    Directory of Open Access Journals (Sweden)

    I.G. Cordes

    1996-08-01

    Full Text Available The conservation status of relic melanistic lizard species occurring in the Saldanha- Langebaan area has been investigated. A contact zone between one melanistic form and a closely related non-melanistic form has been examined in detail. Apart from melanis- tic populations of the girdled lizards, Cordylus niger and C. polywnus, a melanistic morphotype of the Cape legless skink, Acontias meleagris meleagris also occurs in the area. The taxonomic status of this morphotype needs to be investigated. At Mauritz Bay, north of Saldanha, the ranges of C niger and the non-melanistic C cordylus are in contact over a distance of approximately 240 m, with maximum overlap of 70 m. The melanistic populations of C. polyz.onus and A. m. meleagris have relatively large ranges in the Saldanha-Langebaan area and are not threatened by urban development. The C niger population, however, is fragmented into several subpopulations, and those in the Saldanha area, including the contact zone, will be affected if urban development is allowed to continue in the area. As relic populations of other cool-adapted, melanistic invertebrate and lower vertebrate species may also occur in the area, the key areas demarcated by C. niger should be preserved.

  18. Aggressive behavior and performance in the Tegu lizard Tupinambis merianae.

    Science.gov (United States)

    Herrel, Anthony; Andrade, Denis V; de Carvalho, José Eduardo; Brito, Ananda; Abe, Augusto; Navas, Carlos

    2009-01-01

    Aggression is an important component of behavior in many animals and may be crucial to providing individuals with a competitive advantage when resources are limited. Although much is known about the effects of catecholamines and hormones on aggression, relatively few studies have examined the effects of physical performance on aggression. Here we use a large, sexually dimorphic teiid lizard to test whether individuals that show high levels of physical performance (bite force) are also more aggressive toward a potential threat (i.e., a human approaching the lizard). Our results show that independent of their sex, larger individuals with higher bite forces were indeed more aggressive. Moreover, our data show that individuals with higher bite forces tend to show decreased escape responses and are slower, providing evidence for a trade-off between fight and flight abilities. As bite force increased dramatically with body size, we suggest that large body size and bite force may reduce the threshold for an individual to engage in an aggressive encounter, allowing it to potentially gain or maintain resources and fight off predators while minimizing the risk of injury.

  19. Incubation environment impacts the social cognition of adult lizards.

    Science.gov (United States)

    Siviter, Harry; Deeming, D Charles; van Giezen, M F T; Wilkinson, Anna

    2017-11-01

    Recent work exploring the relationship between early environmental conditions and cognition has shown that incubation environment can influence both brain anatomy and performance in simple operant tasks in young lizards. It is currently unknown how it impacts other, potentially more sophisticated, cognitive processes. Social-cognitive abilities, such as gaze following and social learning, are thought to be highly adaptive as they provide a short-cut to acquiring new information. Here, we investigated whether egg incubation temperature influenced two aspects of social cognition, gaze following and social learning in adult reptiles ( Pogona vitticeps ). Incubation temperature did not influence the gaze following ability of the bearded dragons; however, lizards incubated at colder temperatures were quicker at learning a social task and faster at completing that task. These results are the first to show that egg incubation temperature influences the social cognitive abilities of an oviparous reptile species and that it does so differentially depending on the task. Further, the results show that the effect of incubation environment was not ephemeral but lasted long into adulthood. It could thus have potential long-term effects on fitness.

  20. An unusual case of orbito-frontal rod fence stab injury with a good outcome.

    Science.gov (United States)

    Miscusi, Massimo; Arangio, Paolo; De Martino, Luca; De-Giorgio, Fabio; Cascone, Piero; Raco, Antonino

    2013-08-13

    High-energy non-missile penetrating injuries (stab injuries) account for a small percentage of penetrating head injuries and they present a series of special features. A 35-year-old man suffered orbito-frontal? and trans-cranial injuries after falling five meters from a terrace onto a rod iron fence. The removal of the metal rod was performed outside the operating room. The orbital roof was exposed and repaired through a bifrontal craniotomy and the frontal sinuses were cranialised. The orbital floor and zygoma were plated with micro-screws. The patient recovered without significant complications, apart from a slight paresis of the right superior rectus; the ocular globe remained intact.The positive outcome obtained in this very challenging case is attributable to the competency of the Neurotrauma Unit and to the use of a synergistic approach which involved the contribution of neurosurgeons, maxillo-facial surgeons, radiologists and anaesthesiologists.

  1. REMINDER - Compliance with Operational Circular No. 2 on conditions of access to the fenced CERN sites

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The purpose of Operational Circular No. 2 is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. However, recently, the services concerned have noted a significant increase in the instances of non-compliance with those conditions that cannot be tolerated, for example: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the Restaurants; the dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2, namely to refuse access to the site ...

  2. Compliance with Operational Circular No. 2 on conditions of access to the fenced CERN sites

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The purpose of Operational Circular No. 2 is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. However, recently, the services concerned have noted a significant increase in the instances of non-compliance with those conditions that cannot be tolerated, for example: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the Restaurants; the dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2, namely to refuse access to the site...

  3. Temporal distributions, habitat associations and behaviour of the green lizard (Lacerta bilineata and wall lizard (Podarcis muralis on roads in a fragmented landscape in Western France

    Directory of Open Access Journals (Sweden)

    Roger Meek

    2014-12-01

    Full Text Available Observations of the green lizard (Lacerta bilineata and wall lizard (Podarcis muralis on roads in Western France indicated that basking close to the road edge was the predominant activity in L. bilineata but P. muralis mostly foraged. Spatial locations of road mortalities in both species reflected this with the median distances from the road edge greater in P. muralis. Temporal differences in road presence, based on mortality counts and those of live lizards, indicated significantly more lizards were present on roads during late summer and autumn, especially in P. muralis. A significant correlation was found between the monthly presence of live lizards and monthly road mortalities in P. muralis (r = 0.73 but not in L. bilineata (r = 0.64.  Numbers of L. bilineata found on roads bisecting low-density urban areas and roads bordered by hedgerows were higher than expected in relation to the occurrence of these habitats at roadsides. In P. muralis higher than expected numbers were found alongside low-density urban areas and roads bisecting woodland. Generally both species were less commonly seen on roads alongside agricultural areas with no hedgerow border.

  4. Flow characteristics and scaling past highly porous wall-mounted fences

    Science.gov (United States)

    Rodríguez-López, Eduardo; Bruce, Paul J. K.; Buxton, Oliver R. H.

    2017-07-01

    An extensive characterization of the flow past wall-mounted highly porous fences based on single- and multi-scale geometries has been performed using hot-wire anemometry in a low-speed wind tunnel. Whilst drag properties (estimated from the time-averaged momentum equation) seem to be mostly dependent on the grids' blockage ratio; wakes of different size and orientation bars seem to generate distinct behaviours regarding turbulence properties. Far from the near-grid region, the flow is dominated by the presence of two well-differentiated layers: one close to the wall dominated by the near-wall behaviour and another one corresponding to the grid's wake and shear layer, originating from between this and the freestream. It is proposed that the effective thickness of the wall layer can be inferred from the wall-normal profile of root-mean-square streamwise velocity or, alternatively, from the wall-normal profile of streamwise velocity correlation. Using these definitions of wall-layer thickness enables us to collapse different trends of the turbulence behaviour inside this layer. In particular, the root-mean-square level of the wall shear stress fluctuations, longitudinal integral length scale, and spanwise turbulent structure is shown to display a satisfactory scaling with this thickness rather than with the whole thickness of the grid's wake. Moreover, it is shown that certain grids destroy the spanwise arrangement of large turbulence structures in the logarithmic region, which are then re-formed after a particular streamwise extent. It is finally shown that for fences subject to a boundary layer of thickness comparable to their height, the effective thickness of the wall layer scales with the incoming boundary layer thickness. Analogously, it is hypothesized that the growth rate of the internal layer is also partly dependent on the incoming boundary layer thickness.

  5. How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau.

    Science.gov (United States)

    Zeng, Quanchao; Liu, Yang; Xiao, Li; Huang, Yimei

    2017-09-25

    Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures.

  6. A model for the relation between stimulus frequency and spontaneous otoacoustic emissions in lizard papillae.

    Science.gov (United States)

    Wit, Hero P; van Dijk, Pim; Manley, Geoffrey A

    2012-11-01

    Spontaneous otoacoustic emissions (SOAEs) and stimulus frequency otoacoustic emissions (SFOAEs) have been described from lizard ears. Although there are several models for these systems, none has modeled the characteristics of both of these types of otoacoustic emissions based upon their being derived from hair cells as active oscillators. Data from the ears of two lizard species, one lacking a tectorial membrane and one with a chain of tectorial sallets, as described by Bergevin et al. ["Coupled, active oscillators and lizard otoacoustic emissions," AIP Conf. Proc. 1403, 453 (2008)], are modeled as an array of coupled self-sustained oscillators. The model, originally developed by Vilfan and Duke ["Frequency clustering in spontaneous otoacoustic emissions from a lizard's ear," Biophys. J. 95, 4622-4630 (2008)], well describes both the amplitude and phase characteristics of SFOAEs and the relation between SFOAEs and SOAEs.

  7. Rates of pulmonary infection by pentastomids in lizards species from a restinga habitat in northeastern Brazil.

    Science.gov (United States)

    Almeida, W O; Santana, G G; Vieira, W L S; Wanderley, I C; Ribeiro, S C

    2009-02-01

    Pulmonary parasitism by pentastomids was examined in two lizard species inhabiting an area of restinga vegetation (coastal sand dunes) situated in the municipality of Mataraca (6 degrees 29' S and 34 degrees 56' W), on the extreme northern coast of Paraíba State, Brazil. A total of 123 lizards were collected, being 75 specimens of Micrablepharus maximiliani (Gymnophtalmidae) and 48 specimens of Cnemidophorus ocellifer (Teiidae). Only a single species of Pentastomida (Raillietiella mottae) was found parasitizing three females M. maximiliani, with a prevalence of 4% and an average infection intensity of 2.3 +/- 1.3 (range 1-5). The infection rate by pentastomids encountered in the present study was similar to that seen with other species of restinga lizards. Raillietiella mottae is a generalist parasite species that is probably transmitted by common and widely distributed insects making up part of the diet of many insectivorous lizard species from northeastern Brazil.

  8. Chemical constituents of the femoral gland secretions of male tegu lizards (Tupinambis merianae) (Family teiidae).

    Science.gov (United States)

    Martín, José; Chamut, Silvia; Manes, Mario E; López, Pilar

    2011-01-01

    In spite of the importance of chemical signals (pheromones) in the reproductive behaviour of lizards, the chemical compounds secreted by their femoral glands, which may be used as sexual signals, are only known for a few lizard species. Based on mass spectra, obtained by GC-MS, we found 49 lipophilic compounds in femoral gland secretions of male tegu lizards (Tupinambis merianae) (fam. Teiidae), including a very high proportion of carboxylic acids and their esters ranging between n-C8 and n-C20 (mainly octadecanoic and 9,12-octadecadienoic acids), with much less proportions of steroids, tocopherol, aldehydes, and squalene. We discuss the potential function of these compounds in secretions, and compare the compounds found here with those documented for other lizard species.

  9. Hepatozoon kisrae n. sp. infecting the lizard Agama stellio is transmitted by the tick Hyalomma cf. aegyptium

    Directory of Open Access Journals (Sweden)

    Paperna I.

    2002-03-01

    Full Text Available Hepatozoon kisrae n. sp. was found infecting a starred lizard at a site in southeastern Samaria, Palestine. These lizards were also hosts to the ixodid tick Hyolomma cf. aegyptium, which was demonstrated to be the vector of this hemogregarine. Hepatozoon and tick infections occurred in lizards within a very restricted locality; at a second site, nearby, ticks occurred without Hepatozoon infection. Micro- and macromeronts occurred mainly in the lungs, while cyst-like merogonic stages, mainly dizoic, occurred in the liver. Mature intraerythrocytic gametocytes were stout and encapsulated. Development from oocysts to sporocysts took place in the tick hemocoel, and was examined by transmission electron microscopy. Lizards were successfully infected when fed on sporocyst-infected ticks or viscera of infected lizards. Ticks become infected when fed on infected lizards; sporogony was complete when the ticks reached adult stage, over 40 days after initial attachment.

  10. Population demography of an endangered lizard, the Blue Mountains Water Skink

    OpenAIRE

    Dubey, Sylvain; Sinsch, Ulrich; Dehling, Maximilian J; Chevalley, Maya; Shine, Richard

    2013-01-01

    BACKGROUND: Information on the age structure within populations of an endangered species can facilitate effective management. The Blue Mountains Water Skink (Eulamprus leuraensis) is a viviparous scincid lizard that is restricted to < 40 isolated montane swamps in south-eastern Australia. We used skeletochronology of phalanges (corroborated by mark-recapture data) to estimate ages of 222 individuals from 13 populations. RESULTS: These lizards grow rapidly, from neonatal size (30 mm snou...

  11. Variation in the diet of the lizard Tropidurus torquatus along its coastal range in Brazil

    OpenAIRE

    Siqueira, Carla Costa; Kiefer, Mara Cíntia; Sluys, Monique Van; Rocha, Carlos Frederico Duarte

    2013-01-01

    The diet composition of lizards of a given species may vary among different populations. The feeding ecology of the tropidurid lizard Tropidurus torquatus was studied in 10 coastal areas in Brazil in order to detect to what extent the diet varies along its geographic range. A non-metric multidimensional scaling technique revealed three groups of localities according to the diet composition: one characterized by a relatively high consumption of Isoptera, one characterized by a relatively high ...

  12. Rates of pulmonary infection by pentastomids in lizards species from a restinga habitat in northeastern Brazil

    OpenAIRE

    Almeida, WO.; Santana, GG.; Vieira, WLS.; Wanderley, IC.; Ribeiro, SC.

    2009-01-01

    Pulmonary parasitism by pentastomids was examined in two lizard species inhabiting an area of restinga vegetation (coastal sand dunes) situated in the municipality of Mataraca (6° 29' S and 34° 56' W), on the extreme northern coast of Paraíba State, Brazil. A total of 123 lizards were collected, being 75 specimens of Micrablepharus maximiliani (Gymnophtalmidae) and 48 specimens of Cnemidophorus ocellifer (Teiidae). Only a single species of Pentastomida (Raillietiella mottae) was found parasit...

  13. Tegu (teiu) bite: report of human injury caused by a Teiidae lizard.

    Science.gov (United States)

    Haddad, Vidal; Duarte, Marcelo R; Neto, Domingos Garrone

    2008-01-01

    Lizards of the Teiidae family are large reptiles measuring up to 2 meters long. If threatened, they can demonstrate aggressive behavior by whipping their tail and occasionally biting. Here, we report a severe injury following a Teiidae lizard bite on the right index finger of a human. There was significant soft tissue damage and an avulsion fracture of the distal phalanx. He was treated with conservative wound care and prophylactic antibiotics. He developed no evidence of secondary infection and underwent delayed skin grafting.

  14. Preliminary observations on the reproductive cycle of female Tegu lizards (Tupinambis teguizin)

    OpenAIRE

    Yanosky, Ángel Alberto; Mercolli, Claudia

    1991-01-01

    The black tegu lizard, Tupinambis teguixin (Linnaeus 1758) is a common element in the wild all throughout Southamerica except for Chile. This teiid lizard was outstood by earlier travellers such as Sir Charles Waterton who reported for the first time about the delicate food, resembling chicken flesh and frequently consumed by local natives. Despite its relative abundance and both the intense economical and social importance of tegus, as well as its situation in the food web, the reproductive ...

  15. Towards the ecology and conservation of sand lizard (Lacerta agilis) populations in Southern England

    OpenAIRE

    Fearnley, Helen

    2009-01-01

    The sand lizard (Lacerta agilis) is a rare, elusive and cryptic reptile species of conservation importance in the UK. Knowledge of its ecology and behaviour has limited the development of a reliable and effective methodology for population monitoring; this threatens to compromise conservation effort. The behaviour of sand lizards varies seasonally, with sex and with environmental conditions, none of which are fully understood. This aim of this thesis is to further our ecological knowledge of ...

  16. On the water lapping of felines and the water running of lizards: A unifying physical perspective

    OpenAIRE

    Aristoff, Jeffrey M; Stocker, Roman; Reis, Pedro M; Jung, Sunghwan

    2011-01-01

    We consider two biological phenomena taking place at the air-water interface: the water lapping of felines and the water running of lizards. Although seemingly disparate motions, we show that they are intimately linked by their underlying hydrodynamics and belong to a broader class of processes called Froude mechanisms. We describe how both felines and lizards exploit inertia to defeat gravity, and discuss water lapping and water running in the broader context of water exit and water entry, r...

  17. Fossilized Venom: The Unusually Conserved Venom Profiles of Heloderma Species (Beaded Lizards and Gila Monsters)

    Science.gov (United States)

    Koludarov, Ivan; Jackson, Timothy N. W.; Sunagar, Kartik; Nouwens, Amanda; Hendrikx, Iwan; Fry, Bryan G.

    2014-01-01

    Research into snake venoms has revealed extensive variation at all taxonomic levels. Lizard venoms, however, have received scant research attention in general, and no studies of intraclade variation in lizard venom composition have been attempted to date. Despite their iconic status and proven usefulness in drug design and discovery, highly venomous helodermatid lizards (gila monsters and beaded lizards) have remained neglected by toxinological research. Proteomic comparisons of venoms of three helodermatid lizards in this study has unravelled an unusual similarity in venom-composition, despite the long evolutionary time (~30 million years) separating H. suspectum from the other two species included in this study (H. exasperatum and H. horridum). Moreover, several genes encoding the major helodermatid toxins appeared to be extremely well-conserved under the influence of negative selection (but with these results regarded as preliminary due to the scarcity of available sequences). While the feeding ecologies of all species of helodermatid lizard are broadly similar, there are significant morphological differences between species, which impact upon relative niche occupation. PMID:25533521

  18. Fossilized venom: the unusually conserved venom profiles of Heloderma species (beaded lizards and gila monsters).

    Science.gov (United States)

    Koludarov, Ivan; Jackson, Timothy N W; Sunagar, Kartik; Nouwens, Amanda; Hendrikx, Iwan; Fry, Bryan G

    2014-12-22

    Research into snake venoms has revealed extensive variation at all taxonomic levels. Lizard venoms, however, have received scant research attention in general, and no studies of intraclade variation in lizard venom composition have been attempted to date. Despite their iconic status and proven usefulness in drug design and discovery, highly venomous helodermatid lizards (gila monsters and beaded lizards) have remained neglected by toxinological research. Proteomic comparisons of venoms of three helodermatid lizards in this study has unravelled an unusual similarity in venom-composition, despite the long evolutionary time (~30 million years) separating H. suspectum from the other two species included in this study (H. exasperatum and H. horridum). Moreover, several genes encoding the major helodermatid toxins appeared to be extremely well-conserved under the influence of negative selection (but with these results regarded as preliminary due to the scarcity of available sequences). While the feeding ecologies of all species of helodermatid lizard are broadly similar, there are significant morphological differences between species, which impact upon relative niche occupation.

  19. HSF1 and HSF3 cooperatively regulate the heat shock response in lizards.

    Science.gov (United States)

    Takii, Ryosuke; Fujimoto, Mitsuaki; Matsuura, Yuki; Wu, Fangxu; Oshibe, Namiko; Takaki, Eiichi; Katiyar, Arpit; Akashi, Hiroshi; Makino, Takashi; Kawata, Masakado; Nakai, Akira

    2017-01-01

    Cells cope with temperature elevations, which cause protein misfolding, by expressing heat shock proteins (HSPs). This adaptive response is called the heat shock response (HSR), and it is regulated mainly by heat shock transcription factor (HSF). Among the four HSF family members in vertebrates, HSF1 is a master regulator of HSP expression during proteotoxic stress including heat shock in mammals, whereas HSF3 is required for the HSR in birds. To examine whether only one of the HSF family members possesses the potential to induce the HSR in vertebrate animals, we isolated cDNA clones encoding lizard and frog HSF genes. The reconstructed phylogenetic tree of vertebrate HSFs demonstrated that HSF3 in one species is unrelated with that in other species. We found that the DNA-binding activity of both HSF1 and HSF3 in lizard and frog cells was induced in response to heat shock. Unexpectedly, overexpression of lizard and frog HSF3 as well as HSF1 induced HSP70 expression in mouse cells during heat shock, indicating that the two factors have the potential to induce the HSR. Furthermore, knockdown of either HSF3 or HSF1 markedly reduced HSP70 induction in lizard cells and resistance to heat shock. These results demonstrated that HSF1 and HSF3 cooperatively regulate the HSR at least in lizards, and suggest complex mechanisms of the HSR in lizards as well as frogs.

  20. Detection of Campylobacter jejuni in Lizard Faeces from Central Australia Using Quantitative PCR

    Directory of Open Access Journals (Sweden)

    Harriet Whiley

    2016-12-01

    Full Text Available Worldwide, Campylobacter is a significant cause of gastrointestinal illness. It is predominately considered a foodborne pathogen, with human exposure via non-food transmission routes generally overlooked. Current literature has been exploring environmental reservoirs of campylobacteriosis including potential wildlife reservoirs. Given the close proximity between lizards and human habitats in Central Australia, this study examined the presence of Campylobacter jejuni from lizard faeces collected from this region. Of the 51 samples collected, 17 (33% (this included 14/46 (30% wild and 3/5 (60% captive lizard samples were positive for C. jejuni using quantitative PCR (qPCR. This was the first study to investigate the presence of C. jejuni in Australian lizards. This has public health implications regarding the risk of campylobacteriosis from handling of pet reptiles and through cross-contamination or contact with wild lizard faeces. Additionally this has implication for horizontal transmission via lizards of C. jejuni to food production farms. Further research is needed on this environmental reservoir and potential transmission routes to reduce the risk to public health.

  1. Analysis of DNA damage in lizards D.raddei, from areas with different levels of soil contamination using comet assay

    International Nuclear Information System (INIS)

    Simonyan, A.E.; Gevorgyan, A.L.; Sargsyan, A.A.; Arakelyan, M.S.; Minasyan, S.H.

    2015-01-01

    The levels of DNA damage in erythrocytes of rock lizards Darevskia raddei from reserve Shikahogh and Kajaran (Republic of Armenia) and Zuar (Nagorno-Karabakh Republic), were assessed using the comet assay. Female lizards were more sensitive to environmental pollutants than males. Significant positive correlation was found between DNA damage in female lizards and content of Cu, Mo, Pb, Cd, V and As in soil

  2. Genetic regulation of sex differences in songbirds and lizards

    Science.gov (United States)

    Wade, Juli

    2016-01-01

    Sex differences in the morphology of neural and peripheral structures related to reproduction often parallel the frequency of particular behaviours displayed by males and females. In a variety of model organisms, these sex differences are organized in development by gonadal steroids, which also act in adulthood to modulate behavioural expression and in some cases to generate parallel anatomical changes on a seasonal basis. Data collected from diverse species, however, suggest that changes in hormone availability are not sufficient to explain sex and seasonal differences in structure and function. This paper pulls together some of this literature from songbirds and lizards and considers the information in the broader context of taking a comparative approach to investigating genetic mechanisms associated with behavioural neuroendocrinology. PMID:26833833

  3. A telencephalospinal projection in the Tegu lizard (Tupinambis teguixin).

    Science.gov (United States)

    Follett, K A

    1989-09-04

    Tegu lizards (Tupinambis teguixin) were studied to determine the presence of a homologue of the mammalian corticospinal tract. The sources of telencephalic efferent projections to the spinal cord were determined by evaluating the localization of retrogradely transported horseradish peroxidase applied in the cervical spinal cord. Labeled cells were present in subtelencephalic sites reported previously by other authors and, in addition, were found in the principal sensory and motor nuclei of the trigeminal nerve and in the nucleus of the posterior commissure. A telencephalospinal projection was identified, originating in the ventral caudal telencephalon. Histochemical staining revealed a high concentration of acetylcholinesterase in cells and neuropil in the same area. This tract is suggested to be homologous to the mammalian amygdalospinal tract. No reptilian homologue of the corticospinal tract was identified.

  4. Choosing between a rock and a hard place: Camouflage in the round-tailed horned lizard Phrynosoma modestum

    Directory of Open Access Journals (Sweden)

    William E. COOPER, Jr., Wade C. SHERBROOKE

    2012-08-01

    Full Text Available The round-tailed horned lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back. We investigated effectiveness of camouflage in P. modestum and its dependence on stones by placing a lizard in one of two microhabitats (uniform sand or sand with surface rocks approximately the same size as lizards. An observer who knew which microhabitat contained the lizard was asked to locate the lizard visually. Latency to detection was longer and probability of no detection within 60 s was higher for lizards on rock background than on bare sand. In arenas where lizards could choose to occupy rock or bare sand, much higher proportions selected rocky backgrounds throughout the day; at night all lizards slept among stones. A unique posture gives P. modestum a rounded appearance similar to many natural stones. Lizards occasionally adopted the posture, but none did so in response to a nearby experimenter. Stimuli that elicit the posture are unknown. That P. modestum is better camouflaged among rocks than on bare sand and prefers to occupy rocky areas suggests that special resemblance to rocks (masquerade enhances camouflage attributable to coloration and immobility [Current Zoology 58 (4: 541–548, 2012].

  5. An ecophysiological background for biogeographic patterns of two island lizards?

    Science.gov (United States)

    Carretero, Miguel A.; Lopes, Evandro P.; Vasconcelos, Raquel

    2016-12-01

    Distributions of sedentary ectotherms are dependent on temperature and humidity due to their low homeostatic and dispersal abilities. Lizards are strongly conditioned by temperature, but hydric environment may be also important, at least in arid environments. Biotic interactions may also play a role in range patterns, but they are of minor importance in islands where native species monopolize well-delimited niche spaces. On the arid island of São Vicente (Cabo Verde), two endemic lizards display different spatial patterns. While the gecko Tarentola substituta is widely distributed across the island, the skink Chioninia stangeri is restricted to the NE, which is cooler, more humid, and vegetated. We hypothesized that this is due to differences in the fundamental niche, specifically in ecophysiology. We predict that C. stangeri should select for lower temperatures and lose more water by evaporation than T. substituta. We submitted adults of each species to standard experiments to assess preferred body temperatures (Tp) and evaporative water loss (EWL) rates, and examined the variation between species and through time using repeated-measures AN(C)OVAs. Results only partially supported our expectations. Contrary to the prediction, skinks attained higher Tp than geckos but in the long term showed a trend for higher EWL as predicted. Thus, while ecophysiology certainly contributes to functional interpretation of species distributions, it needs to be combined with other evidence such as habitat use and evolutionary history. These findings will be useful to perform mechanistic models to better understand the impact of climate change and habitat disturbance on these endemic species.

  6. Behavioral hypothermia of a domesticated lizard under treatment of the hypometabolic agent 3-iodothyronamine.

    Science.gov (United States)

    Ha, Kyoungbong; Shin, Haksup; Ju, Hyunwoo; Chung, Chan-Moon; Choi, Inho

    2017-05-03

    Ectothermic animals rely on behavioral thermoregulation due to low capacity of heat production and storage. Previously, lizards were shown to achieve 'fever' during microbial infection by increasing their preferred body temperature (PBT) behaviorally, thereby attaining a relatively high survival rate. The purpose of this study was to investigate whether domesticated lizards pursued 'behavioral hypothermia' induced by a hypometabolic agent 3-iodothyronamine (T1AM). We found that treatment with 8.0 mg/kg T1AM caused a lizard species, the leopard gecko (Eublepharis macularius), to decrease its ventilation and oxygen consumption rates 0.64- and 0.76-fold, respectively, compared to those of the control (P<0.05). The lizards, habituated at an ambient temperature of 30 ± 0.5°C, also showed a significant decrease in the PBT range over a freely accessible thermal gradient between 5°C and 45°C. The upper limit of the PBT in the treated lizards lowered from 31.9°C to 30.6°C, and the lower limit from 29.5°C to 26.3°C (P<0.001). These findings demonstrate that the treated lizards pursued behavioral hypothermia in conjunction with hypoventilation and hypometabolism. Because prior studies reported a similar hypometabolic response in T1AM-injected laboratory mice, the domesticated lizards, as a part of the vertebrate phylogeny, may be a useful laboratory model for biological and pharmacological researches such as drug potency test.

  7. Diagnostic sensitivity of ultrasound, radiography and computed tomography for gender determination in four species of lizards.

    Science.gov (United States)

    Di Ianni, Francesco; Volta, Antonella; Pelizzone, Igor; Manfredi, Sabrina; Gnudi, Giacomo; Parmigiani, Enrico

    2015-01-01

    Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards. © 2014 American College of Veterinary Radiology.

  8. Operational Circular No.2 (Rev. 2) - Conditions of access to the fenced parts of the CERN site

    CERN Multimedia

    2014-01-01

    Operational Circular No. 2 (Rev. 2) entitled “Conditions of access to the fenced parts of the CERN site” and its “implementation measures”, approved by the Director-General following discussion at the Standing Concertation Committee meeting on 20 May 2014 and entering into force on 1 September 2014, are available on the intranet site of the Human Resources Department (see here).   This circular is applicable to members of the personnel and other persons concerned. It cancels and replaces Operational Circular No. 2 (Rev. 1) entitled “Conditions of access to the fenced parts of the CERN site”, of April 1998. In particular, the revised circular provides for the possibility of mandating a person responsible for the proper implementation of the circular, specifies the rules relating to vehicles allowed on the site and the respective responsibilities of their owners, and relaxes certain administrative formalities in case of loss, theft or di...

  9. Operational Circular No. 2 (Rev. 3) - Conditions of access to the fenced parts of the CERN site

    CERN Multimedia

    HR Department

    2015-01-01

    Operational Circular No. 2 (Rev. 3) entitled "Conditions of access to the fenced parts of the CERN site", approved by the Director-General following discussion in the Standing Concertation Committee meeting on 24 September 2015, is now available via this link.   This revised circular cancels and replaces Operational Circular No. 2 (Rev. 2) also entitled "Conditions of access to the fenced parts of the CERN site", of September 2014. The circular was revised predominantly in order to specify that access to the CERN site is granted to CERN Pension Fund beneficiaries only provided that they are actually in receipt of payments from the Fund; and to allow the Director-General to permit special types of vehicles on site, such as trailers. It also includes a certain number of text improvements and an updated version of the implementation measures, in particular with regard to vehicle identification, road traffic and parking.  

  10. Effectiveness of Chain Link Turtle Fence and Culverts in Reducing Turtle Mortality and Providing Connectivity along U.S. Hwy 83, Valentine National Wildlife Refuge, Nebraska, USA

    Science.gov (United States)

    2017-12-01

    We evaluated the effectiveness of existing turtle fences through collecting and analyzing turtle mortality data along U.S. Hwy 83, in and around Valentine National Wildlife Refuge, Nebraska, USA. We also investigated the level of connectivity for tur...

  11. Promotional effect of phosphorus doping on the activity of the Fe-N/C catalyst for the oxygen reduction reaction

    DEFF Research Database (Denmark)

    Hu, Yang; Zhu, Jianbin; Lv, Qing

    2015-01-01

    Cost-effective, active and stable electrocatalysts for the oxygen reduction reaction (ORR) are highly desirable for the wide-spread adoption of technologies such as fuel cells and metal-air batteries. Among the already reported non-precious metal catalysts, carbon-supported transition metal...... to that for the undoped Fe-N/C catalyst. The activity and durability of the catalysts are demonstrated in direct methanol fuel cells....

  12. A genetic discontinuity in moose (Alces alces) in Alaska corresponds with fenced transportation infrastructure

    Science.gov (United States)

    Wilson, Robert E.; Farley, Sean D.; McDonough, Thomas J.; Talbot, Sandra L.; Barboza, Perry S.

    2015-01-01

    The strength and arrangement of movement barriers can impact the connectivity among habitat patches. Anthropogenic barriers (e.g. roads) are a source of habitat fragmentation that can disrupt these resource networks and can have an influence on the spatial genetic structure of populations. Using microsatellite data, we evaluated whether observed genetic structure of moose (Alces alces) populations were associated with human activities (e.g. roads) in the urban habitat of Anchorage and rural habitat on the Kenai Peninsula, Alaska. We found evidence of a recent genetic subdivision among moose in Anchorage that corresponds to a major highway and associated infrastructure. This subdivision is most likely due to restrictions in gene flow due to alterations to the highway (e.g. moose-resistant fencing with one-way gates) and a significant increase in traffic volume over the past 30 years; genetic subdivision was not detected on the Kenai Peninsula in an area not bisected by a major highway. This study illustrates that anthropogenic barriers can substructure wildlife populations within a few generations and highlights the value of genetic assessments to determine the effects on connectivity among habitat patches in conjunction with behavioral and ecological data..

  13. [Nutritional habits in children and adolescents practicing fencing. Part 1. Meal consumption].

    Science.gov (United States)

    Radzimirska-Graczyk, Monika; Chalcarz, Wojciech

    2009-01-01

    The aim of this study was to assess habits related to eating meals in children and adolescents who attended sports schools. The days with training and the days free of training were analysed separately. The questionnaires on the number and frequency of eating meals were filled in by 141 children and adolescents who practised fencing and attended sports classes in primary and secondary schools. The influence of gender and age on the number and frequency of eating meals was analysed by means of the SPSS 12.0 PL for Windows computer programme. The studied children's and adolescents' habits related to eating meals were highly unfavourable, especially in females from secondary school, mainly due to a very low percentage of students who ate meals regularly, lunch in particular. Boys ate more meals than girls. Especially disconcerting was a very low number of meals eaten by females from secondary school, which may imply a risk of anorexia. Children and adolescents who attend sports schools should be educated on nutrition and the relation between food habits, nutritional status and achieving success in sport. Females from secondary schools should be informed about the danger of anorexia.

  14. [Nutritional habits in children and adolescents practicing fencing. Part II. Characteristics of eating between meals].

    Science.gov (United States)

    Chalcarz, Wojciech; Radzimirska-Graczyk, Monika

    2010-01-01

    The aim of this study was to assess the longest interval between meals, eating until the feeling of satiety and eating between meals in children and adolescents who attended sports schools. The questionnaires on were filled in by 141 children and adolescents who practised fencing and attended sports classes in primary and secondary schools. The days with training and the days free of training were analysed separately. The influence of gender and age on the longest interval between meals, eating until the feeling of satiety and eating between meals on the days with training and the days free of training was analysed by means of the SPSS 12.0 PL for Windows computer programme. Gender and age had statistically significant influence on the longest interval between meals, eating until the feeling of satiety and eating vegetables, cured meat, sweets and energy drinks between meals. Eating between main meals was prevalent in the studied population. Higher percentage of girls ate fruit and vegetables between main meals, while higher percentage of boys ate sandwiches, irrespectively of the type of the day--with training or free of training.

  15. Plutonium assessment modeling: government policy, non-proliferation, and the government fence

    International Nuclear Information System (INIS)

    Kurstedt, H.A. Jr.; Nachlas, J.A.

    1977-01-01

    Assessment modeling for the evaluation of plutonium as an energy resource is stressed, and generic mathematical model forms are outlined. Representative necessary objective functions are developed. Constraints and assumptions are listed. An example involving present-day light water reactor technology is demonstrated. Technical, environmental, and political implications are drawn. Specific new directions for analysis are suggested. The position of the boundary of government control and responsibility--the government exclusion fence--is shown to be a critical, but overlooked, constraint. Existing governmental uranium stockpiles may be an unmentioned, though important, constraint. Plutonium is the most abundant proven energy equivalent and most controversial energy resource. Plutonium results from an intermediate nuclear reactor processing stage starting with the raw material 238 U. Therefore, the plutonium resource differs from the 238 U resource only through minimal conversion losses and through the political and/or social will to perform the conversion. The relative abundance of 238 U, and therefore of plutonium is high. There is a great need to assess plutonium in relation to the potential available energy for a society in short supply

  16. ANALYSIS OF THE 2012 EUROPEAN FENCING CHAMPIONSHIP FOR MEN AND WOMEN, HELD IN LEGNANO, ITALY

    Directory of Open Access Journals (Sweden)

    Krassimir Petkov

    2013-07-01

    Full Text Available We analyzed the participations and the rankings of the different European states in the 2012 Europen Championship. The diversity, which fencing brings with it in United Europe always attracts a lot of the attention of the sport public as an innovative and dynamic sport discipline. In this article the total number of contestants and the number of contestants in the different weapons for both sexes are monitored. We found that the most competitive disciplines were epee men discipline with 92 participants and epee women discipline with 75 participants, and the least competitive – foil women discipline with 40 participants. The nation that won the biggest number of medals was Russia with total of 8 medals 4 of wich golden. The first three states ranked by the competitors in the top sixteen group for all weapons are as follows: Russia with 16%, Italy with 15% and Germany with 13%. After observing the technics most widely used by the most successful contestants in this competition we reached to the followig recommendations for Bulgarian fencers to perform better: 1. For a better ranking to be achieved it is necessary attention to be paid on improving the technics of attack, using movements of high difficulty and speed and 2. It is important to improve dramatically the quality of both the attack and the defence.

  17. Fe-N-C catalyst modified graphene sponge as a cathode material for lithium-oxygen battery

    International Nuclear Information System (INIS)

    Yu, Ling; Shen, Yue; Huang, Yunhui

    2014-01-01

    Highlights: • Hydrothermally-synthesized graphene sponge is excellent skeleton of Li-O 2 cathode. • Fe-N-C catalyst loaded on GS was attained via pyrolysis of FePc and GS composites. • High capacity and good cyclability were achieved with Fe-N-GS air electrode. • The synergy of porous structure and catalytic activity leads to the high performance. - Abstract: The cathode of a lithium-oxygen battery needs the synergism of a porous conducting material and a catalyst to facilitate the formation and decomposition of lithium peroxide. Here we introduce a graphene sponge (GS) modified with Fe-N-C catalyst for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The porous, 3-dimensional conductive and free standing nature of the graphene sponge makes it become excellent skeleton of cathode for lithium-oxygen battery. The Fe-N-C catalyst nanoparticles dispersed uniformly on the graphene sheets show excellent catalytic reactivity in both discharge and charge processes. This kind of composite material greatly improves the capacity and cyclability of the lithium-oxygen battery. With dimethyl sulphoxide as electrolyte, the capacity reaches 6762 mAh g −1 which is twice of the pure graphene sponge. In addition, the cell containing Fe-N-GS air electrode exhibits stable cyclic performance and effective reduction of charge potential plateau, indicating that Fe-N-GS is promising as an OER catalyst in rechargeable lithium-air batteries

  18. What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards

    Science.gov (United States)

    Kopena, Renata; López, Pilar; Martín, José

    2014-12-01

    In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards ( Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

  19. Response of lizards to high-severity wildfires in a southern United States mixed pine/hardwood forest

    Science.gov (United States)

    Adam ​Duarte; Donald J. Brown; Michael R. J. Forstner

    2017-01-01

    High-severity forest fires are increasing in large areas of the southern and western United States as the climate becomes warmer and drier. Natural resource managers need a better understanding of the short- and long-term effects of wildfires on lizard populations, but there is a paucity of studies focused on lizard-wildfire relationships. We used a before-after,...

  20. Legitimate seed dispersal by lizards in an alpine habitat: The case of Berberis empetrifolia (Berberidaceae) dispersed by Liolaemus belii (Tropiduridae)

    Science.gov (United States)

    Celedón-Neghme, Constanza; San Martin, Leonardo A.; Victoriano, Pedro F.; Cavieres, Lohengrin A.

    2008-05-01

    In this study we determined the effect of seed passage through Liolaemus bellii lizard digestive tracts on germination of fleshy-fruited Andean shrub species Berberis empetrifolia (Berberidaceae), and evaluated the effect of this passage on seed coat characteristics. In addition, we assessed the spatial patterns of fecal deposition by lizards onto various microhabitats available in the Andean environments of central Chile. The germination rate and the final percentage of lizard-ingested B. empetrifolia seeds was greater than control seeds. Comparing photographs and seed coat histological cuts, we suggest that the cutine wax present on seed coats from lizard-ingested seeds was probably removed by abrasion inside the lizards' digestive tract. Sixty-two percent of the lizard's feces was deposited on bare soil near rocks commonly inhabited by lizards. However, this microhabitat represents only 29% of the available ground cover at the study site. By enhancing seed germination and depositing seeds onto potential safe sites for recruitment, the lizard Liolaemus bellii is acting, at least qualitatively, as an effective disperser of Berberis empetrifolia.

  1. Historical colonization and dispersal limitation supplement climate and topography in shaping species richness of African lizards (Reptilia: Agaminae)

    NARCIS (Netherlands)

    Kissling, W.D.; Blach-Overgaard, A.; Zwaan, R.E.; Wagner, P.

    2016-01-01

    To what extent deep-time dispersal limitation shapes present-day biodiversity at broad spatial scales remains elusive. Here, we compiled a continental dataset on the distributions of African lizard species in the reptile subfamily Agaminae (a relatively young, Neogene radiation of agamid lizards

  2. 137Cs and 90Sr IN lizards of Semipalatinsk test site.

    Science.gov (United States)

    Panitskiy, А V; Lukashenko, S N; Kadyrova, N Zh

    2017-01-01

    The paper provides research results of 137 Cs and 90 Sr radionuclides concentrations in bodies of Lacertidae family lizards, inhabiting different parts of Semipalatinsk Test Site, and the parameters of these radionuclides' transfer into lizards' bodies. It shows that high activity concentration of radionuclides in lizards' bodies can be noticed if they live directly at locally contaminated areas. Since the distance from contaminated spots exceeds home range of the studied animals, no increased values of radionuclides' activity were found in the animal bodies. At some individual radioactively contaminated spots, very high activity concentrations of 90 Sr radionuclide up to 7.8 × 10 5  Bq kg -1 were found in lizards. So under certain conditions, lizards can significantly contribute to radionuclides redistribution in the natural environment. Mean concentration ratios (CR) of radionuclides were as follows: 137 Cs-6.2 × 10 -3 , 90 Sr-1.1 × 10 -2 . Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Variations upon a theme: Australian lizards provide insights into the endocrine control of vertebrate reproductive cycles.

    Science.gov (United States)

    Jones, Susan M

    2017-04-01

    Australian lizards exhibit a broad array of different reproductive strategies and provide an extraordinary diversity and range of models with which to address fundamental problems in reproductive biology. Studies on lizards have frequently led to new insights into hormonal regulatory pathways or mechanisms of control, but we have detailed knowledge of the reproductive cycle in only a small percentage of known species. This review provides an overview and synthesis of current knowledge of the hormonal control of reproductive cycles in Australian lizards. Agamid lizards have provided useful models with which to test hypotheses about the hormonal regulation of the expression of reproductive behaviors, while research on viviparous skinks is providing insights into the evolution of the endocrine control of gestation. However, in order to better understand the potential risks that environmental factors such as climate change and endocrine disrupting chemicals pose to our fauna, better knowledge is required of the fundamental characteristics of the reproductive cycle in a broader range of lizard species. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Learning outdoors: male lizards show flexible spatial learning under semi-natural conditions

    Science.gov (United States)

    Noble, Daniel W. A.; Carazo, Pau; Whiting, Martin J.

    2012-01-01

    Spatial cognition is predicted to be a fundamental component of fitness in many lizard species, and yet some studies suggest that it is relatively slow and inflexible. However, such claims are based on work conducted using experimental designs or in artificial contexts that may underestimate their cognitive abilities. We used a biologically realistic experimental procedure (using simulated predatory attacks) to study spatial learning and its flexibility in the lizard Eulamprus quoyii in semi-natural outdoor enclosures under similar conditions to those experienced by lizards in the wild. To evaluate the flexibility of spatial learning, we conducted a reversal spatial-learning task in which positive and negative reinforcements of learnt spatial stimuli were switched. Nineteen (32%) male lizards learnt both tasks within 10 days (spatial task mean: 8.16 ± 0.69 (s.e.) and reversal spatial task mean: 10.74 ± 0.98 (s.e.) trials). We demonstrate that E. quoyii are capable of flexible spatial learning and suggest that future studies focus on a range of lizard species which differ in phylogeny and/or ecology, using biologically relevant cognitive tasks, in an effort to bridge the cognitive divide between ecto- and endotherms. PMID:23075525

  5. Accumulation of transposable elements in Hox gene clusters during adaptive radiation of Anolis lizards.

    Science.gov (United States)

    Feiner, Nathalie

    2016-10-12

    Transposable elements (TEs) are DNA sequences that can insert elsewhere in the genome and modify genome structure and gene regulation. The role of TEs in evolution is contentious. One hypothesis posits that TE activity generates genomic incompatibilities that can cause reproductive isolation between incipient species. This predicts that TEs will accumulate during speciation events. Here, I tested the prediction that extant lineages with a relatively high rate of speciation have a high number of TEs in their genomes. I sequenced and analysed the TE content of a marker genomic region (Hox clusters) in Anolis lizards, a classic case of an adaptive radiation. Unlike other vertebrates, including closely related lizards, Anolis lizards have high numbers of TEs in their Hox clusters, genomic regions that regulate development of the morphological adaptations that characterize habitat specialists in these lizards. Following a burst of TE activity in the lineage leading to extant Anolis, TEs have continued to accumulate during or after speciation events, resulting in a positive relationship between TE density and lineage speciation rate. These results are consistent with the prediction that TE activity contributes to adaptive radiation by promoting speciation. Although there was no evidence that TE density per se is associated with ecological morphology, the activity of TEs in Hox clusters could have been a rich source for phenotypic variation that may have facilitated the rapid parallel morphological adaptation to microhabitats seen in extant Anolis lizards. © 2016 The Author(s).

  6. High antipredatory efficiency of insular lizards: a warning signal of excessive specimen collection?

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    Miguel Delibes

    Full Text Available We live-captured lizards on islands in the Gulf of California and the Baja California peninsula mainland, and compared their ability to escape predation. Contrary to expectations, endemic lizard species from uninhabited islands fled from humans earlier and more efficiently than those from peninsular mainland areas. In fact, 58.2% (n=146 of the lizards we tried to capture on the various islands escaped successfully, while this percentage was only 14.4% (n=160 on the peninsular mainland. Separate evidence (e.g., proportion of regenerated tails, low human population at the collection areas, etc. challenges several potential explanations for the higher antipredatory efficiency of insular lizards (e.g., more predation pressure on islands, habituation to humans on the peninsula, etc.. Instead, we suggest that the ability of insular lizards to avoid predators may be related to harvesting by humans, perhaps due to the value of endemic species as rare taxonomic entities. If this hypothesis is correct, predation-related behavioral changes in rare species could provide early warning signals of their over-exploitation, thus encouraging the adoption of conservation measures.

  7. Patterns of cranial ontogeny in lacertid lizards: morphological and allometric disparity.

    Science.gov (United States)

    Urošević, A; Ljubisavljević, K; Ivanović, A

    2013-02-01

    We explored the ontogenetic dynamics of the morphological and allometric disparity in the cranium shapes of twelve lacertid lizard species. The analysed species (Darevskia praticola, Dinarolacerta mosorensis, Iberolacerta horvathi, Lacerta agilis, L. trilineata, L. viridis, Podarcis erhardii, P. melisellensis, P. muralis, P. sicula, P. taurica and Zootoca vivipara) can be classified into different ecomorphs: terrestrial lizards that inhabit vegetated habitats (habitats with lush or sparse vegetation), saxicolous and shrub-climbing lizards. We observed that there was an overall increase in the morphological disparity (MD) during the ontogeny of the lacertid lizards. The ventral cranium, which is involved in the mechanics of jaw movement and feeding, showed higher levels of MD, an ontogenetic shift in the morphospace planes and more variable allometric patterns than more conserved dorsal crania. With respect to ecology, the allometric trajectories of the shrub-climbing species tended to cluster together, whereas the allometric trajectories of the saxicolous species were highly dispersed. Our results indicate that the ontogenetic patterns of morphological and allometric disparity in the lacertid lizards are modified by ecology and functional constraints and that the identical mechanisms that lead to intraspecific morphological variation also produce morphological divergence at higher taxonomic levels. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  8. Watch out where you sleep: nocturnal sleeping behaviour of Bay Island lizards

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    Nitya Prakash Mohanty

    2016-04-01

    Full Text Available Sleeping exposes lizards to predation. Therefore, sleeping strategies must be directed towards avoiding predation and might vary among syntopic species. We studied sleeping site characteristics of two syntopic, congeneric lizards—the Bay Island forest lizard, Coryphophylax subcristatus and the short-tailed Bay Island lizard, C. brevicaudus and evaluated inter-specific differences. We measured structural, microclimatic and potential predator avoidance at the sleeping perches of 386 C. subcristatus and 185 C. brevicaudus. Contrary to our expectation, we found similar perch use in both species. The lizards appeared to use narrow girth perch plants and accessed perches by moving both vertically and horizontally. Most lizards slept on leaves, with their heads directed towards the potential path of a predator approaching from the plant base. There was no inter-specific competition in the choices of sleeping perches. These choices indicate an anti-predator strategy involving both tactile and visual cues. This study provides insight into a rarely studied behaviour in reptiles and its adaptive significance.

  9. Short-term dispersal response of an endangered Australian lizard varies with time of year.

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    Mehregan Ebrahimi

    Full Text Available Dispersal is an important component in the demography of animal populations. Many animals show seasonal changes in their tendency to disperse, reflecting changes in resource availability, mating opportunities, or in population age structure at the time when new offspring enter the population. Understanding when and why dispersal occurs can be important for the management of endangered species. The pygmy bluetongue lizard is an endangered Australian species that occupies and defends single burrow refuges for extended periods of time, rarely moving far from the burrow entrance. However, previous pitfall trapping data have suggested movement of adult males in spring and of juveniles in autumn of each year. In the current study we compared behaviours of adult lizards each month, over the spring-summer activity period over two consecutive field seasons, to provide deeper understanding of the seasonal dispersal pattern. We released adult pygmy bluetongue lizards into a central area, provided with artificial burrows, within large enclosures, and monitored the behaviour and movements of the released lizards over a four day period. There was a consistent decline in time spent basking, amount of movement around burrow entrances, and rates of dispersal from the central release area from early spring to late summer. Results could be relevant to understanding and managing natural populations and for any translocation attempts of this endangered lizard species.

  10. Microgeographic variation in locomotor traits among lizards in a human-built environment

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    Colin Donihue

    2016-03-01

    Full Text Available Microgeographic variation in fitness-relevant traits may be more common than previously appreciated. The fitness of many vertebrates is directly related to their locomotor capacity, a whole-organism trait integrating behavior, morphology, and physiology. Because locomotion is inextricably related to context, I hypothesized that it might vary with habitat structure in a wide-ranging lizard, Podarcis erhardii, found in the Greek Cyclade Islands. I compared lizard populations living on human-built rock walls, a novel habitat with complex vertical structure, with nearby lizard populations that are naive to human-built infrastructure and live in flat, loose-substrate habitat. I tested for differences in morphology, behavior, and performance. Lizards from built sites were larger and had significantly (and relatively longer forelimbs and hindlimbs. The differences in hindlimb morphology were especially pronounced for distal components—the foot and longest toe. These morphologies facilitated a significant behavioral shift in jumping propensity across a rocky experimental substrate. I found no difference in maximum velocity between these populations; however, females originating from wall sites potentially accelerated faster over the rocky experimental substrate. The variation between these closely neighboring populations suggests that the lizards inhabiting walls have experienced a suite of trait changes enabling them to take advantage of the novel habitat structure created by humans.

  11. Toxicity of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in three vertebrate species.

    Science.gov (United States)

    Johnson, Mark S; McFarland, Craig A; Bazar, Matthew A; Quinn, Michael J; LaFiandra, Emily May; Talent, Larry G

    2010-04-01

    The explosive, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine or high-melting explosive (HMX), has been found in soils in areas used for testing and training by the military. Many of these areas contain habitat for valued wildlife species. In an effort to better understand the environmental consequences from exposure, a reptilian (western fence lizard [Sceloporus occidentalis]), an amphibian (red-backed salamander [Plethodon cinereus]), and a mammalian species (rabbit [Oryctolagus cuniculus]) were exposed to HMX under controlled laboratory conditions. Lizards and rabbits were exposed to HMX by way of corn oil through gavage, and salamanders were exposed to HMX in soil. Two deaths occurred from acute oral exposures to lizards to 5000 mg HMX/kg BW. Histological and gross pathologic assessment suggested gut impaction as a possible cause of death. Salamanders exposed to concentrations of HMX in soil 24 h after oral exposures. An LD(50) for rabbits was calculated as 93 mg/kg (95% confidence interval 76-117). A subacute 14-day testing regime found a lowest observed effect level of 10 mg/kg-d and a no observed adverse effect level of 5 mg/kg-d based on hyperkinesia and seizure incidence, although changes suggesting functional hepatic alterations were also found. These data suggest that physiologic differences between species, particularly in gastrointestinal structure and function, can affect the absorption of HMX and hence lead to marked differences in toxicity from exposure to the same compound.

  12. Solubilization and purification of melatonin receptors from lizard brain

    International Nuclear Information System (INIS)

    Rivkees, S.A.; Conron, R.W. Jr.; Reppert, S.M.

    1990-01-01

    Melatonin receptors in lizard brain were identified and characterized using 125 I-labeled melatonin ([ 125 I]MEL) after solubilization with the detergent digitonin. Saturation studies of solubilized material revealed a high affinity binding site, with an apparent equilibrium dissociation constant of 181 +/- 45 pM. Binding was reversible and inhibited by melatonin and closely related analogs, but not by serotonin or norepinephrine. Treatment of solubilized material with the non-hydrolyzable GTP analog, guanosine 5'-(3-O-thiotriphosphate) (GTP-gamma-S), significantly reduced receptor affinity. Gel filtration chromatography of solubilized melatonin receptors revealed a high affinity, large (Mr 400,000) peak of specific binding. Pretreatment with GTP-gamma-S before solubilization resulted in elution of a lower affinity, smaller (Mr 150,000) peak of specific binding. To purify solubilized receptors, a novel affinity chromatography resin was developed by coupling 6-hydroxymelatonin with Epoxy-activated Sepharose 6B. Using this resin, melatonin receptors were purified approximately 10,000-fold. Purified material retained the pharmacologic specificity of melatonin receptors. These results show that melatonin receptors that bind ligand after detergent treatment can be solubilized and substantially purified by affinity chromatography

  13. Solubilization and purification of melatonin receptors from lizard brain.

    Science.gov (United States)

    Rivkees, S A; Conron, R W; Reppert, S M

    1990-09-01

    Melatonin receptors in lizard brain were identified and characterized using 125I-labeled melatonin ([125I]MEL) after solubilization with the detergent digitonin. Saturation studies of solubilized material revealed a high affinity binding site, with an apparent equilibrium dissociation constant of 181 +/- 45 pM. Binding was reversible and inhibited by melatonin and closely related analogs, but not by serotonin or norepinephrine. Treatment of solubilized material with the non-hydrolyzable GTP analog, guanosine 5'-(3-O-thiotriphosphate) (GTP-gamma-S), significantly reduced receptor affinity. Gel filtration chromatography of solubilized melatonin receptors revealed a high affinity, large (Mr 400,000) peak of specific binding. Pretreatment with GTP-gamma-S before solubilization resulted in elution of a lower affinity, smaller (Mr 150,000) peak of specific binding. To purify solubilized receptors, a novel affinity chromatography resin was developed by coupling 6-hydroxymelatonin with Epoxy-activated Sepharose 6B. Using this resin, melatonin receptors were purified approximately 10,000-fold. Purified material retained the pharmacologic specificity of melatonin receptors. These results show that melatonin receptors that bind ligand after detergent treatment can be solubilized and substantially purified by affinity chromatography.

  14. Speed and stamina trade-off in lacertid lizards.

    Science.gov (United States)

    Vanhooydonck, B; Van Damme, R; Aerts, P

    2001-05-01

    Morphological and physiological considerations suggest that sprinting ability and endurance capacity put conflicting demands on the design of an animal's locomotor apparatus and therefore cannot be maximized simultaneously. To test this hypothesis, we correlated size-corrected maximal sprint speed and stamina of 12 species of lacertid lizards. Phylogenetically independent contrasts of sprint speed and stamina showed a significant negative relationship, giving support to the idea of an evolutionary trade-off between the two performance measures. To test the hypothesis that the trade-off is mediated by a conflict in morphological requirements, we correlated both performance traits with snout-vent length, size-corrected estimates of body mass and limb length, and relative hindlimb length (the residuals of the relationship between hind- and forelimb length). Fast-running species had hindlimbs that were long compared to their forelimbs. None of the other size or shape variables showed a significant relationship with speed or endurance. We conclude that the evolution of sprint capacity may be constrained by the need for endurance capacity and vice versa, but the design conflict underlying this trade-off has yet to be identified.

  15. The effect of parity on morphological evolution among phrynosomatid lizards.

    Science.gov (United States)

    Oufiero, C E; Gartner, G E A

    2014-11-01

    The shift from egg laying to live-bearing is one of the most well-studied transitions in evolutionary biology. Few studies, however, have assessed the effect of this transition on morphological evolution. Here, we evaluated the effect of reproductive mode on the morphological evolution of 10 traits, among 108 species of phrynosomatid lizards. We assess whether the requirement for passing shelled eggs through the pelvic girdle has led to morphological constraints in oviparous species and whether long gestation times in viviparous species have led to constraints in locomotor morphology. We fit models to the data that vary both in their tempo (strength and rate of selection) and mode of evolution (Brownian or Ornstein-Uhlenbeck) and estimates of trait optima. We found that most traits are best fit by a generalized multipeak OU model, suggesting differing trait optima for viviparous vs. oviparous species. Additionally, rates (σ(2) ) of both pelvic girdle and forelimb trait evolution varied with parity; viviparous species had higher rates. Hindlimb traits, however, exhibited no difference in σ(2) between parity modes. In a functional context, our results suggest that the passage of shelled eggs constrains the morphology of the pelvic girdle, but we found no evidence of morphological constraint of the locomotor apparatus in viviparous species. Our results are consistent with recent lineage diversification analyses, leading to the conclusion that transitions to viviparity increase both lineage and morphological diversification. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  16. Developmental origin of limb size variation in lizards.

    Science.gov (United States)

    Andrews, Robin M; Skewes, Sable A

    2017-05-01

    In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

  17. Visual motion detection and habitat preference in Anolis lizards.

    Science.gov (United States)

    Steinberg, David S; Leal, Manuel

    2016-11-01

    The perception of visual stimuli has been a major area of inquiry in sensory ecology, and much of this work has focused on coloration. However, for visually oriented organisms, the process of visual motion detection is often equally crucial to survival and reproduction. Despite the importance of motion detection to many organisms' daily activities, the degree of interspecific variation in the perception of visual motion remains largely unexplored. Furthermore, the factors driving this potential variation (e.g., ecology or evolutionary history) along with the effects of such variation on behavior are unknown. We used a behavioral assay under laboratory conditions to quantify the visual motion detection systems of three species of Puerto Rican Anolis lizard that prefer distinct structural habitat types. We then compared our results to data previously collected for anoles from Cuba, Puerto Rico, and Central America. Our findings indicate that general visual motion detection parameters are similar across species, regardless of habitat preference or evolutionary history. We argue that these conserved sensory properties may drive the evolution of visual communication behavior in this clade.

  18. Sister chromosome pairing maintains heterozygosity in parthenogenetic lizards.

    Science.gov (United States)

    Lutes, Aracely A; Neaves, William B; Baumann, Diana P; Wiegraebe, Winfried; Baumann, Peter

    2010-03-11

    Although bisexual reproduction has proven to be highly successful, parthenogenetic all-female populations occur frequently in certain taxa, including the whiptail lizards of the genus Aspidoscelis. Allozyme analysis revealed a high degree of fixed heterozygosity in these parthenogenetic species, supporting the view that they originated from hybridization events between related sexual species. It has remained unclear how the meiotic program is altered to produce diploid eggs while maintaining heterozygosity. Here we show that meiosis commences with twice the number of chromosomes in parthenogenetic versus sexual species, a mechanism that provides the basis for generating gametes with unreduced chromosome content without fundamental deviation from the classic meiotic program. Our observation of synaptonemal complexes and chiasmata demonstrate that a typical meiotic program occurs and that heterozygosity is not maintained by bypassing recombination. Instead, fluorescent in situ hybridization probes that distinguish between homologues reveal that bivalents form between sister chromosomes, the genetically identical products of the first of two premeiotic replication cycles. Sister chromosome pairing provides a mechanism for the maintenance of heterozygosity, which is critical for offsetting the reduced fitness associated with the lack of genetic diversity in parthenogenetic species.

  19. “Sexual” behavior in parthenogenetic lizards (Cnemidophorus)

    Science.gov (United States)

    Crews, David; Fitzgerald, Kevin T.

    1980-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Basic data on the behavior of parthenogens are lacking, however. We have discovered, from observations of captive Cnemidophorus uniparens, C. velox, and C. tesselatus, behavior patterns remarkably similar to the courtship and copulatory behavior of closely related sexual species. Briefly, in separately housed pairs, one lizard was repeatedly seen to mount and ride its cagemate and appose the cloacal regions. Dissection or palpation revealed that, in each instance, the courted animal was reproductively active, having ovaries containing large, preovulatory follicles, while the courting animal was either reproductively inactive or postovulatory, having ovaries containing only small, undeveloped follicles. These observations are significant for the questions they raise. For example, is this behavior a nonfunctional vestige of the species' ancestry, or is this behavior necessary for successful reproduction in the species (e.g., by priming reproductive neuroendocrine mechanisms as has been demonstrated in sexual species)? Images PMID:16592761

  20. Ascending connections to the forebrain in the Tegu lizard.

    Science.gov (United States)

    Lohman, A H; van Woerden-Verkley, I

    1978-12-01

    The ascending connections to the striatum and the cortex of the Tegu lizard, Tupinambis nigropunctatus, were studied by means of anterograde fiber degeneration and retrograde axonal transport. The striatum receives projections by way of the dorsal peduncle of the lateral forebrain bundle from four dorsal thalamic nuclei: nucleus rotundus, nucleus reuniens, the posterior part of the dorsal lateral geniculate nucleus and nucleus dorsomedialis. The former three nuclei project to circumscribed areas of the dorsal striatum, whereas nucleus dorsomedialis has a distribution to the whole dorsal striatum. Other sources of origin to the striatum are the mesencephalic reticular formation, substantia nigra and nucleus cerebelli lateralis. With the exception of the latter afferentation all these projections are ipsilateral. The ascending connections to the pallium originate for the major part from nucleus dorsolateralis anterior of the dorsal thalamus. The fibers course in both the medial forebrain bundle and the dorsal peduncle of the lateral forebrain bundle and terminate ipsilaterally in the middle of the molecular layer of the small-celled part of the mediodorsal cortex and bilaterally above the intermediate region of the dorsal cortex. The latter area is reached also by fibers from the septal area. The large-celled part of the mediodorsal cortex receives projections from nucleus raphes superior and the corpus mammillare.

  1. History of reptile placentology, part III: Giacomini's 1891 histological monograph on lizard placentation.

    Science.gov (United States)

    Blackburn, D G; Paulesu, L; Avanzati, A M; Roth, M

    2017-12-01

    By the 1890s, placental arrangements had been documented macroscopically in lizards and fishes, but placental studies on such species lagged far behind research on mammals. In 1891, the biologist Ercole Giacomini (at the University of Siena, Italy) published the first histological analysis of a reptile placenta. Focusing on a placentotrophic lizard (Chalcides chalcides) with a morphologically complex placenta, Giacomini documented the histological and cellular bases for placental nutrient transfer and gas exchange. In conjunction with a follow-up study in 1906, he demonstrated that placental structure is correlated with function and can vary dramatically between related species. Giacomini's work was highly influential in showing that placentation in lizards had converged evolutionarily on that of mammals, while establishing reptile placentology as a highly promising area for future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Lizards, ticks and contributions to Australian parasitology: C. Michael Bull (1947-2016).

    Science.gov (United States)

    Godfrey, Stephanie S; Gardner, Michael G

    2017-12-01

    Professor C. Michael Bull was a great scientist and mentor, and an Associate Editor of this journal. While his research career spanned the fields of behavioural ecology, conservation biology and herpetology, in this article, we pay tribute to his major contribution to Australian parasitology. Mike authored more than eighty articles on host-parasite ecology, and revealed major insights into the biology and ecology of ticks from his long term study of the parapatric boundary of two tick species ( Amblyomma limbatum and Bothriocroton hydrosauri ) on the sleepy lizard ( Tiliqua rugosa ). In this article, we provide an overview of how this research journey developed to become one of the longest-running studies of lizards and their ticks, totalling 35 years of continuous surveys of ticks on lizards, and the insights and knowledge that he generated along that journey.

  3. Nutritional perfomance of Tupinambis merianae lizards fed with corn starch as source of energy

    Directory of Open Access Journals (Sweden)

    Harold Vega Parry

    2009-07-01

    Full Text Available Efficiency in processing complex carbohydrates as a source of energy was studied in Tupinambis merianae lizards. Four isoproteic and isoenergetic diets in which different percentages of corn starch substituted fat (0, 10, 20 and 30 dry matter in the diet were provided. Even though consumption was similar in all diets, growth and feeding conversion rates decreased significantly with corn starch supplies of 10% and more. At the end of the trial, pancreatic alpha-amylase activity showed correlated increases, yet these were insufficient to compensate corn starch supplies. Results suggest that Tupinambis merianae lizards have a restricted omnivorous capacity. Therefore, diet formulation for these lizards should exclude high molecular weight carbohydrates.

  4. The nematode community in the Atlantic rainforest lizard Enyalius perditus Jackson, from south-eastern Brazil.

    Science.gov (United States)

    Barreto-Lima, A F; Toledo, G M; Anjos, L A

    2012-12-01

    Studies focusing on communities of helminths from Brazilian lizards are increasing, but there are many blanks in the knowledge of parasitic fauna of wild fauna. This lack of knowledge hampers understanding of ecological and parasitological aspects of involved species. Moreover, the majority of research has focused on parasitic fauna of lizards from families Tropiduridae and Scincidae. Only a few studies have looked at lizards from the family Leiosauridae, including some species of Enyalius. This study presents data on the gastrointestinal parasite fauna of Enyalius perditus and their relationships with ecological aspects of hosts in a disturbed Atlantic rainforest area in the state of Minas Gerais, south-eastern Brazil. Two nematode species, Oswaldocruzia burseyi [(Molineidae) and Strongyluris oscari (Heterakidae) were found. Nematode species showed an aggregated distribution in this host population, with O. burseyi being more aggregated than S. oscari. The present study extends the range of occurrence of O. burseyi to the Brazilian continental area.

  5. Changes in developmental stages of the egyptian lizard chalcides ocellatus due to different radiation exposures

    International Nuclear Information System (INIS)

    Roushdy, H.M.; Mazhar, Fatma M.; Ashry, Madiha A.; Refaat, Sanaa M.

    1979-01-01

    Adult male and female Chalcides Ocellatus lizards of approximately the same age and size were irradiated at doses of 1000, 1500, 2000 and 4000 rads from a Cobalt-60 Gamma cell at a dose rate of 100 rads/sec. Examinations were carried out at 2 days, 1, 3 and 4 weeks post-irradiation and indicated the following: The LD 50 /30 was found to be 1250 rads. Radiation exposure had no significant effect on lizard's body length measurements along the whole experimentation period. Radiation exposure caused a progressive decrease in body weights of lizards which was often obscured by interfering fluctuations in body weights due to pregnancy development, embryo retention or abortion cases

  6. Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards

    Science.gov (United States)

    Daza, Juan D.; Stanley, Edward L.; Wagner, Philipp; Bauer, Aaron M.; Grimaldi, David A.

    2016-01-01

    Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships. PMID:26973870

  7. Roadside verges as habitats for endangered lizard-orchids (Himantoglossum spp.): Ecological traps or refuges?

    Science.gov (United States)

    Fekete, Réka; Nagy, Timea; Bódis, Judit; Biró, Éva; Löki, Viktor; Süveges, Kristóf; Takács, Attila; Tökölyi, Jácint; Molnár V, Attila

    2017-12-31

    Alterations in traditional land use practices have led to severe declines in the area of semi-natural grasslands, thereby seriously threatening plant and animal species dependent on these habitats. Small anthropogenic managed habitats, like roadsides can act as refuges and might play an important role in conserving these species. Colonization of roadside verges by endangered lizard orchids (Himantoglossum spp.) has long been known, but few studies have systematically explored the suitability of roadside habitats for these orchids and the impact of roads on them. In this paper we present results of targeted surveys of three lizard orchid taxa on roadsides from eight European countries. During these surveys we searched for lizard orchids inhabiting roadside verges and recorded their distance from road, aspects of the roadside environment, as well as vegetative and reproductive characteristics of individual plants. We found large numbers of lizard orchids on roadside verges. Distance from roads was not uniformly distributed: orchids occurred more closely to roads than expected by chance. This suggests that regular management of roadsides (e.g. mowing) might enhance colonization and survival of lizard orchids. On the other hand, we also found that close proximity to roads negatively affects reproductive success, suggesting that the immediate vicinity of roads might act as an ecological trap (i.e. favorable in terms of colonization and survival but unfavorable in terms of reproduction). Nonetheless, the fact that significant and viable populations are maintained at roadsides suggests that traditionally managed roadside verges may allow long-term persistence of lizard orchid populations and may serve as refuges in a landscape context. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Reactions of green lizards (Lacerta viridis) to major repellent compounds secreted by Graphosoma lineatum (Heteroptera: Pentatomidae).

    Science.gov (United States)

    Gregorovičová, Martina; Černíková, Alena

    2015-06-01

    The chemical defence of Heteroptera is primarily based on repellent secretions which signal the potential toxicity of the bug to its predators. We tested the aversive reactions of green lizards (Lacerta viridis) towards the major compounds of the defensive secretion of Graphosoma lineatum, specifically: (i) a mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (ii) a mixture of these three aldehydes and tridecane; (iii) oxoaldehyde: (E)-4-oxohex-2-enal; (iv) secretion extracted from metathoracic scent glands of G. lineatum adults and (v) hexane as a non-polar solvent. All chemicals were presented on a palatable food (Tenebrio molitor larvae). The aversive reactions of the green lizards towards the mealworms were evaluated by observing the approach latencies, attack latencies and approach-attack intervals. The green lizards exhibited a strong aversive reaction to the mixture of three aldehydes. Tridecane reduced the aversive reaction to the aldehyde mixture. Oxoaldehyde caused the weakest, but still significant, aversive reaction. The secretion from whole metathoracic scent glands also clearly had an aversive effect on the green lizards. Moreover, when a living specimen of G. lineatum or Pyrrhocoris apterus (another aposematic red-and-black prey) was presented to the green lizards before the trials with the aldehyde mixture, the aversive effect of the mixture was enhanced. In conclusion, the mixture of three aldehydes had the strong aversive effect and could signal the potential toxicity of G. lineatum to the green lizards. Copyright © 2015 Elsevier GmbH. All rights reserved.

  9. Temporal overlap of humans and giant lizards (Varanidae; Squamata) in Pleistocene Australia

    Science.gov (United States)

    Price, Gilbert J.; Louys, Julien; Cramb, Jonathan; Feng, Yue-xing; Zhao, Jian-xin; Hocknull, Scott A.; Webb, Gregory E.; Nguyen, Ai Duc; Joannes-Boyau, Renaud

    2015-10-01

    An obvious but key prerequisite to testing hypotheses concerning the role of humans in the extinction of late Quaternary 'megafauna' is demonstrating that humans and the extinct taxa overlapped, both temporally and spatially. In many regions, a paucity of reliably dated fossil occurrences of megafauna makes it challenging, if not impossible, to test many of the leading extinction hypotheses. The giant monitor lizards of Australia are a case in point. Despite commonly being argued to have suffered extinction at the hands of the first human colonisers (who arrived by 50 ka), it has never been reliably demonstrated that giant monitors and humans temporally overlapped in Australia. Here we present the results of an integrated U-Th and 14C dating study of a late Pleistocene fossil deposit that has yielded the youngest dated remains of giant monitor lizards in Australia. The site, Colosseum Chamber, is a cave deposit in the Mt Etna region, central eastern Australia. Sixteen new dates were generated and demonstrate that the bulk of the material in the deposit accumulated since ca. 50 ka. The new monitor fossil is, minimally, 30 ky younger than the previous youngest reliably dated record for giant lizards in Australia and for the first time, demonstrates that on a continental scale, humans and giant lizards overlapped in time. The new record brings the existing geochronological dataset for Australian giant monitor lizards to seven dated occurrences. With such sparse data, we are hesitant to argue that our new date represents the time of their extinction from the continent. Rather, we suspect that future fossil collecting will yield new samples both older and younger than 50 ka. Nevertheless, we unequivocally demonstrate that humans and giant monitor lizards overlapped temporally in Australia, and thus, humans can only now be considered potential drivers for their extinction.

  10. The Role of Diet in Shaping the Chemical Signal Design of Lacertid Lizards.

    Science.gov (United States)

    Baeckens, Simon; García-Roa, Roberto; Martín, José; Van Damme, Raoul

    2017-09-01

    Lizards communicate with others via chemical signals, the composition of which may vary among species. Although the selective pressures and constraints affecting chemical signal diversity at the species level remain poorly understood, the possible role of diet has been largely neglected. The chemical signals of many lizards originate from the femoral glands that exude a mixture of semiochemicals, and may be used in a variety of contexts. We analyzed the lipophilic fraction of the glandular secretions of 45 species of lacertid lizard species by gas chromatography/mass spectrometry. The proportions of nine major chemical classes (alcohols, aldehydes, fatty acids, furanones, ketones, steroids, terpenoids, tocopherols and waxy esters), the relative contributions of these different classes ('chemical diversity'), and the total number of different lipophilic compounds ('chemical richness') varied greatly among species. We examined whether interspecific differences in these chemical variables could be coupled to interspecific variation in diet using data from the literature. In addition, we compared chemical signal composition among species that almost never, occasionally, or often eat plant material. We found little support for the hypothesis that the chemical profile of a given species' secretion depends on the type of food consumed. Diet breadth did not correlate with chemical diversity or richness. The amount of plants or ants consumed did not affect the relative contribution of any of the nine major chemical classes to the secretion. Chemical diversity did not differ among lizards with different levels of plant consumption; however, chemical richness was low in species with an exclusive arthropod diet, suggesting that incorporating plants in the diet enables lizards to increase the number of compounds allocated to secretions, likely because a (partly) herbivorous diet allows them to include compounds of plant origin that are unavailable in animal prey. Still, overall

  11. Yolk coelomitis in a white-throated monitor lizard (Varanus albigularis : short communication

    Directory of Open Access Journals (Sweden)

    B.R. Gardner

    2010-05-01

    Full Text Available Yolk coelomitis as a result of pre-ovulatory follicular stasis is a common disorder in captive reptiles, especially in captive lizards of various genera. The clinical signs are generally fairly non-specific and diagnosis is based on clinical signs together with most of the common diagnostic modalities. The condition is most likely a husbandry and environment-related reproductive disorder. It has not been reported in wild free-living specimens. This report describes the clinical presentation and post mortem lesions in a white-throated monitor lizard that died during treatment for non-specific clinical signs related to a severe yolk coelomitis.

  12. Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis.

    Science.gov (United States)

    Winck, Gisele R; Hatano, Fabio; Vrcibradic, Davor; VAN Sluys, Monique; Rocha, Carlos F D

    2016-01-01

    Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba). We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic) using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

  13. Intrapulmonary receptors in the Tegu lizard: I. Sensitivity to CO2.

    Science.gov (United States)

    Feede, M R; Kuhlmann, W D; Scheid, P

    1977-02-01

    Single unit vagal recordings from intrapulmonary receptors were obtained in decerebrate, paralyzed lizards both during pump ventilation and during unidirectional ventilation on the cannulated, sack-shaped lung. Two types of receptors were identified: (1) CO2-receptors, which increased their discharge frequency as intrapulmonary CO2 concentration decreased but were not sensitive to stretch of the lung. (2) Mechanoreceptors, which rapidly increased discharge frequency when the lung was stretched. These receptors' CO2 sensitivity varied. Lungs of lizards thus appeared to possess both CO2 receptors, which have functional characteristics similar to those in birds, and mechanoreceptors with properties similar to stretch receptors in mammals.

  14. Identification key to species of the flying lizard genus Draco Linnaeus, 1758 (Squamata: Agamidae in Thailand

    Directory of Open Access Journals (Sweden)

    Nattawut Srichairat

    2017-02-01

    Full Text Available A species identification key of flying lizards in the genus Draco from Thailand was constructed based on 521 preserved specimens from collections during 1967–2012 in the Natural History Museum (THNHM, National Science Museum, Technopolis, Pathum Thani, Thailand. Regardless of sexual characters, four characters were used to identify Draco spp. lizards: 1 nostril direction; 2 type of tympanum; 3 pattern of patagium; and 4 snout with or without a series of scales forming a Y-shaped figure. The specimens were identified into nine species—Draco blanfordii, Draco fimbriatus, Draco maculatus, Draco maximus, Draco melanopogon, Draco obscurus, Draco quinquefasciatus, Draco taeniopterus and Draco volans.

  15. Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis

    Directory of Open Access Journals (Sweden)

    GISELE R. WINCK

    2016-01-01

    Full Text Available ABSTRACT Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba. We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

  16. Locomotion, Energetics, Performance, and Behavior: A Mammalian Perspective on Lizards, and Vice Versa.

    Science.gov (United States)

    Garland, Theodore; Albuquerque, Ralph L

    2017-08-01

    Animals are constrained by their abilities and by interactions with environmental factors, such as low ambient temperatures. These constraints range from physical impossibilities to energetic inefficiencies, and may entail trade-offs. Some of the constraints related to locomotion and activity metabolism can be illustrated through allometric comparisons of mammals and lizards, as representative terrestrial vertebrate endotherms and ectotherms, respectively, because these lineages differ greatly in aerobic metabolic capacities, resting energetic costs, and thermoregulatory patterns. Allometric comparisons are both useful and unavoidable, but "outlier" species (unusual for their clade) can also inform evolutionary scenarios, as they help indicate extremes of possible adaptation within mammalian and saurian levels of organization. We compared mammals and lizards for standard metabolic rate (SMR), maximal oxygen consumption during forced exercise (VO2max), net (incremental) cost of transport (NCT), maximal aerobic speed (MAS), daily movement distance (DMD), daily energy expenditure (DEE) during the active season, and the ecological cost of transport (ECT = percentage of DEE attributable to locomotion). (Snakes were excluded because their limbless locomotion has no counterpart in terrestrial mammals.) We only considered lizard SMR, VO2max, NCT, MAS, and sprint speed data if measured at 35-40 °C. On average, MAS is ∼7.4-fold higher in mammals, whereas SMR and VO2max are ∼6-fold greater, but values for all three of these traits overlap (or almost overlap) between mammals and lizards, a fact that has not previously been appreciated. Previous studies show that sprint speeds are similar for smaller mammals and lizards, but at larger sizes lizards are not as fast as some mammals. Mammals move ∼6-fold further each day than lizards, and DMD is by far the most variable trait considered here, but their NCT is similar. Mammals exceed lizards by ∼11.4-fold for DEE. On

  17. DNA damage and micronuclei in parthenogenetic and bisexual Darevskia rock lizards from the areas with different levels of soil pollution.

    Science.gov (United States)

    Simonyan, Anna; Hovhannisyan, Galina; Sargsyan, Anzhela; Arakelyan, Marine; Minasyan, Seyran; Aroutiounian, Rouben

    2018-06-15

    Natural species are widely used as indicator organisms to estimate of the impact of environmental pollution. Here we present the results of first study of a reliability of parthenogenetic Darevskia аrmeniaca and bisexual Darevskia raddei rock lizards as sentinels for monitoring of environmental genotoxicity. The comet assay and micronucleus test were applied to the lizards sampled in six areas in Armenia and Artsakh with different levels of soil contamination. The results obtained showed a clear relationship between the pollution level of lizards' habitats and the frequency of DNA damage in the comet assay. Low baseline frequency of micronuclei in D. аrmeniaca and D. raddei, however, makes this parameter ineffective for environmental genotoxicity evaluation. The parthenogenetic lizards D. аrmeniaca showed higher sensitivity toward genotoxic pollutions compared with bisexual D. raddei living in the same environment. The correlations between soil content of heavy metals Cr, Cu, Zn, Mo, Pb and DNA damage in D. аrmeniaca and between Cu, As, Mo, Pb and DNA damage in D. raddei were revealed. Overall, the lizards D. raddei and D. аrmeniaca appeared to be sensitive species in detecting soil pollution in natural environment. The application of the comet assay in Darevskia lizard species can be considered as a more appropriate method than a micronucleus test. The use of parthenogenetic lizards D. аrmeniaca as bioindicator will permit to assess the environmental genotoxicity independent of the genetic polymorphism of bisexual species. Copyright © 2018. Published by Elsevier Inc.

  18. A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre Islands (Guadeloupe, French West Indies).

    Science.gov (United States)

    Bochaton, Corentin; Boistel, Renaud; Casagrande, Fabrice; Grouard, Sandrine; Bailon, Salvador

    2016-06-29

    Today, Diploglossine lizards (Anguidae) are common on the Greater Antillean Islands (West Indies), where they are represented by many endemic species. However these lizards are very rare on the Lesser Antillean Islands, where they are only represented by a single species, the Montserrat galliwasp (Diploglossus montisserrati). Here, we show that diploglossine lizards were present in the past on other Lesser Antillean islands, by reporting the discovery of Anguidae fossil remains in two Amerindian archaeological deposits and in a modern deposit. These remains are compared to skeletons of extant diploglossine lizards, including D. montisserrati, using X-ray microtomography of the type specimen of this critically endangered lizard. We also conducted a histological study of the osteoderms in order to estimate the putative age of the specimen. Our results show that the fossil specimens correspond to a member of the Diploglossus genus presenting strong similarities, but also minor morphological differences with D. montisserrati, although we postulate that these differences are not sufficient to warrant the description of a new species. These specimens, identified as Diploglossus sp., provide a new comparison point for the study of fossil diploglossine lizards and reflect the historical 17(th) century mentions of anguid lizards, which had not been observed since.

  19. Pampean lizard assemblage from subtropical Brazil: a temporal analysis

    Directory of Open Access Journals (Sweden)

    Gisele R. Winck

    2011-12-01

    Full Text Available The increasing human occupation of natural environments is one of the greatest threats to biodiversity. To mitigate the negative anthropogenic effects, it is necessary to understand the characteristics of natural populations and the natural history of species. A study was conducted with an assemblage of lizards from a disturbed area of the Pampa biome, from February 2001 to January 2004. The assemblage showed a unimodal seasonal pattern, with the recruitment period occurring during the warmer months. The captures were seasonal for two of the three monitored years, and concentrated within warmer months. The minimum temperature explained the number of catches for the assemblage as a whole. However, when the species were analyzed individually, the temperature only explained the seasonal occurrence of Teius oculatus. The abundance of species was significantly different in the third year of study for Cercosaura schreibersii and Ophiodes striatus. This latter species was no longer registered in the study area from May 2003 until the end of the study. Therefore, O. striatus may be more sensitive to environmental changes, considering the events of change in vegetation during the study. With frequent and increasing environmental disturbances, it is necessary to take conservation measures and encourage the increase of knowledge on Pampean lizards.O crescimento da ocupação humana sobre ambientes naturais é uma das maiores ameaças à biodiversidade. Para amenizar os efeitos negativos antropogênicos, é necessário entender as características das populações naturais, e a história natural das espécies. Um estudo foi conduzido com uma assembeia de lagartos de uma área perturbada do Pampa, de fevereiro de 2002 a janeiro de 2004. A assembleia apresentou padrão sazonal unimodal, com recrutamento ocorrendo durante os meses mais quentes. As capturas foram sazonais durante dois dos três anos monitorados, e concentradas nos meses mais quentes. A

  20. Polymorphic ROS scavenging revealed by CCCP in a lizard

    Science.gov (United States)

    Olsson, Mats; Wilson, Mark; Isaksson, Caroline; Uller, Tobias

    2009-07-01

    Ingestion of antioxidants has been argued to scavenge circulating reactive molecules (e.g., free radicals), play a part in mate choice (by mediating access to this important resource), and perhaps increase life span. However, recent work has come to question these relationships. We have shown elsewhere in the polychromatic lizard, Ctenophorus pictus, that diet supplementation of carotenoids as antioxidants does not depress circulating natural reactive oxygen species (ROS) levels and leads to no corresponding improvement of color traits. However, a much stronger test would be to experimentally manipulate the ROS levels themselves and assess carotenoid-induced ROS depression. Here, we achieve this by using carbonyl cyanide 3-chlorophenylhydrazone, which elevates superoxide (SO) formation approximately threefold at 10 μM in this model system. We then look for depressing effects on ROS of the carotenoids in order to assess whether ‘super-production’ of SO makes carotenoid effects on elevated ROS levels detectable. The rationale for this treatment was that if not even such elevated levels of SO are reduced by carotenoid supplementation, the putative link carotenoids, ROS depression, and mate quality (in terms of antioxidant capacity) is highly questionable. We conclude that there is no significant effect of carotenoids on mean SO levels even at the induced ROS levels. However, our results showed a significant interaction effect between carotenoid treatment and male color, with red males having higher ROS levels than yellow males. We suggest that this may be because different pigments are differently involved in the generation of the integumental colors in the two morphs with concomitant effects on ROS depletion depending on carotenoid uptake or allocation to coloration and antioxidation.

  1. Landscape structure and live fences in Andes Colombian agrosystems: upper basin of the Cane-Iguaque River

    Directory of Open Access Journals (Sweden)

    Javier Otero

    2009-12-01

    Full Text Available Changes in land use have generated a new landscape configuration in the Andino orobiome (mountain range of the tropical Andes, resulting in a mosaic of cultivation and pastures interrupted by small fragments of forest and live fences. This has resulted in an ongoing decrease in the biodiversity of this biome. In the upper basin of the Cane-Iguaque River (Villa de Levya-Boyacá, Colombia, located 2 600-3 000 m above the Cordillera Oriental, over three time periods in 1960, 1984, and 2004, we characterized the structure, patterns, and evolution of the overall landscape and of the live fences (used as tools in biodiversity conservation and considered to be desirable alternatives to nonlive fences in farming production systems within an agricultural landscape. To do this, we interpreted high- resolution satellite images using a landscape ecology approach and applied landscape map metrics. We found that the natural forests have been transformed by pastures and cultivation, and that although live fences cover only a small portion of the total landscape (4.6%, they have an important effect on landscape structure and biodiversity. There has been an increase in live fences, especially between 1960 and 1984, as well as an increase in their density. However, there has been a reduction in the average length of live fences over the periods that we studied. This could be due in part to changes in the types of agricultural products that have been cultivated in recent years, with an increase in potatoes and a decrease in other vegetables, and also by resource extraction of timber and fuel wood. In the studied area, agricultural production was sustained while biodiversity conservation was improved by the use of live fences. Therefore, live fences should be considered not only as part of an agriculturally productive area, but also as an important element of a multi-functional landscape that contributes to the maintenance of biodiversity and provides resources of

  2. Body condition, diet and ecosystem function of red deer (Cervus elaphus) in a fenced nature reserve

    DEFF Research Database (Denmark)

    Fløjgaard, Camilla; De Barba, Marta; Taberlet, Pierre

    2017-01-01

    is therefore relevant to increase understanding of herbivores' ecosystem function and to inform management. In this study, we focused on red deer, Cervus elaphus, in a fenced nature reserve in Denmark, where the deer are managed as ecosystem engineers to contribute to biodiversity conservation. We measured...... on variation in body condition within the population. Our findings call for the need to consider the consequences of management practices, including culling or supplemental feeding, on the outcomes of habitat restoration, and more broadly underline the importance of preserving the overall breath of herbivore...... ecosystem functions for effective biodiversity conservation....

  3. Income and working time of a Fencing Master in Bologna in the 15th and early 16th century

    Directory of Open Access Journals (Sweden)

    Battistini Alessandro

    2016-04-01

    Full Text Available Since ancient times, the master-at-arms profession has always been considered essential for the education of the nobility and the common citizenship, especially in the Middle Ages. Yet, we know nothing about the real standard of living of these characters. The recent discovery of documents, which report the sums earned by fencing masters to teach combat disciplines, has brought us the possibility to estimate how highly this profession was regarded, and what its actual economic value was in the Italian late Middle Ages. They also give us also a material view into the modes of operation of a sala d’arme in those times.

  4. A potential recovery of a population of the sand lizard Liolaemus lutzae Mertens, 1938 in an area within its range: a lizard endemic and threatened with extinction

    Directory of Open Access Journals (Sweden)

    CFD. Rocha

    Full Text Available The endemic and threatened lizard Liolaemus lutzae has a relatively small geographic range restricted to only 200 km of along the coast of Rio de Janeiro State, Brazil, which are habitats under intensive anthropic disturbance. At the Barra da Tijuca beach, in Rio de Janeiro city an estimate of the population abundance made in 1991, compared to a previous estimate made in 1984, showed a considerable decrease (about 65%. Most of the decrease was attributed to anthropic disturbances that locally affected the beach vegetation, the species habitat. In this study we present estimates made in 2002 and in 2006 at the same area and compare them with the estimates of 1984 and 1991, using the same methodology in order to make comparable the data from different samplings years and to evaluate the present status of the local population. The estimated indexes of L. lutzae abundance in 2002 and in 2006 were higher than that of 1991. There was a significant increase in the mean number of recorded lizards in 2002 compared to 1991, but the mean number of lizards sighted in 2006 remained stable when compared with that of 2002. Our data based on the index of abundance recorded suggested that the number of L. lutzae at Barra da Tijuca beach recorded increased, which can be indicative of a potential recovery of the local population.

  5. Does diet in lacertid lizards reflect prey availability? Evidence for selective predation in the Aeolian wall lizard, Podarcis raffonei (Mertens, 1952 (Reptilia, Lacertidae

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    Pietro Lo Cascio

    2011-06-01

    Full Text Available In this paper the invertebrate fauna occurring on Scoglio Faraglione, a tiny Aeolian island (AeolianArchipelago, NE Sicily inhabited by a population of the critically endangered lacertid lizard Podarcis raffonei(Mertens, 1952, was censused at different seasons and the resulting data were then compared with dataobtained analysing prey composition and prey abundance in the diet of the lizards occurring on the same islet.The diet of Podarcis raffonei was mainly based on insects and other arthropods. The results indicate that dietcomposition is not directly influenced by prey availability and temporal prey abundance, and that there isstrong evidence indicating selective predation. Lizards prey upon a number of arthropod categories fewer thanthat recorded in field. Some invertebrate taxa (e.g. Diptera and Gastropoda are really less attractive for lizardsand are rarely preyed or not preyed at all despite their spatial and/or temporal abundance. This suggests thatPodarcis raffonei is able to operate a hierarchical choice within the range of prey items constituting its preyspectrum, probably through the ability to discriminate between prey chemicals or visually oriented predation.

  6. Pentastomid, Raillietiella mottae Almeida, Freire and Lopes, 2008, infecting lizards in an area of caatinga, northeast, Brazil

    OpenAIRE

    Almeida, WO.; Santana, GG.; Vieira, WLS.; Wanderley, IC.; Freire, EMX.; Vasconcellos, A.

    2008-01-01

    Pentastomids can infect the respiratory tract of lizards, causing their death and as a result influencing the population size of hosts. Despite this, studies on rates of pulmonary infection of Brazilian lizards, including those living in Caatinga ecosystems of northeastern Brazil are scarce. Active collections of lizards were performed from October to December 2004 in an area of Caatinga of the Estação Experimental de São João do Cariri - EESJC (07º 25' S and 36º 30' W), located in the state ...

  7. Original and regenerating lizard tail cartilage contain putative resident stem/progenitor cells.

    Science.gov (United States)

    Alibardi, Lorenzo

    2015-11-01

    Regeneration of cartilaginous tissues is limited in mammals but it occurs with variable extension in lizards (reptiles), including in their vertebrae. The ability of lizard vertebrae to regenerate cartilaginous tissue that is later replaced with bone has been analyzed using tritiated thymidine autoradiography and 5BrdU immunocytochemistry after single pulse or prolonged-pulse and chase experiments. The massive cartilage regeneration that can restore broad vertebral regions and gives rise to a long cartilaginous tube in the regenerating tail, depends from the permanence of some chondrogenic cells within adult vertebrae. Few cells that retain tritiated thymidine or 5-bromodeoxy-uridine for over 35 days are mainly localized in the inter-vertebral cartilage and in sparse chondrogenic regions of the neural arch of the vertebrae, suggesting that they are putative resident stem/progenitor cells. The study supports previous hypothesis indicating that the massive regeneration of the cartilaginous tissue in damaged vertebrae and in the regenerating tail of lizards derive from resident stem cells mainly present in the cartilaginous areas of the vertebrae including in the perichondrium that are retained in adult lizards as growing centers for most of their lifetime. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 75 FR 77801 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Science.gov (United States)

    2010-12-14

    ... public lands in Texas. It is evident that the dunes sagebrush lizard is still present at the park, but... expected to contribute to habitat loss, modification, or fragmentation in the future include wind and solar... and Solar Energy Development Eastern New Mexico and western Texas are highly suitable areas for wind...

  9. Foraging mode of serpentiform, grass-living cordylid lizards: A case ...

    African Journals Online (AJOL)

    Nine C. anguina were habituated in glass terraria to accept mealworms offered to them. When all lizards accepted food without hesitation, they were tested for their ability to discriminate among three different odours presented to them in a randomized block design: prey odours consisting of mealworm surface odours, ...

  10. Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

    Directory of Open Access Journals (Sweden)

    Michael L. AVERY, John D. EISEMANN, Kandy L. KEACHER,Peter J. SAVARIE

    2011-10-01

    Full Text Available Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in bait which is lower than currently used in commercial baits for commensal rodent control. We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed [Current Zoology 57 (5: 625–629, 2011].

  11. Divergent calcium signaling in RBCs from Tropidurus torquatus (Squamata – Tropiduridae strengthen classification in lizard evolution

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    Garcia Célia RS

    2007-08-01

    Full Text Available Abstract Background We have previously reported that a Teiid lizard red blood cells (RBCs such as Ameiva ameiva and Tupinambis merianae controls intracellular calcium levels by displaying multiple mechanisms. In these cells, calcium stores could be discharged not only by: thapsigargin, but also by the Na+/H+ ionophore monensin, K+/H+ ionophore nigericin and the H+ pump inhibitor bafilomycin as well as ionomycin. Moreover, these lizards possess a P2Y-type purinoceptors that mobilize Ca2+ from intracellular stores upon ATP addition. Results Here we report, that RBCs from the tropidurid lizard Tropidurus torquatus store Ca2+ in endoplasmic reticulum (ER pool but unlike in the referred Teiidae, these cells do not store calcium in monensin-nigericin sensitive pools. Moreover, mitochondria from T. torquatus RBCs accumulate Ca2+. Addition of ATP to a calcium-free medium does not increase the [Ca2+]c levels, however in a calcium medium we observe an increase in cytosolic calcium. This is an indication that purinergic receptors in these cells are P2X-like. Conclusion T. torquatus RBCs present different mechanisms from Teiid lizard red blood cells (RBCs, for controlling its intracellular calcium levels. At T. torquatus the ion is only stored at endoplasmic reticulum and mitochondria. Moreover activation of purinergic receptor, P2X type, was able to induce an influx of calcium from extracelullar medium. These studies contribute to the understanding of the evolution of calcium homeostasis and signaling in nucleated RBCs.

  12. Behavioral implications of mechanistic ecology II: the African rainbow lizard, Agama agama

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.; James, F.C.

    1979-01-01

    The daily and seasonal activity of the African rainbow lizard, Agama agama is predicted in terms of heat transfer models for the microenvironment and the lizard. The models, originally developed for the temperate Mohave Desert and for the desert iguana, Dipsosaurus dorsalis, have been refined and are applicable to a tropical area and a tropical species. Field microclimate measurements and observations of lizard activity and food consumption by different sizes of lizards are consistent with these models. Environmental constraints on activity times, sun vs shade locations, height above the ground and postures are described. The sensitivity of the metabolic predictions to different maximum temperature preferences and behavioral options are discussed. The balance between maintenance energy savings via lower thermoregulatory temperatures and time available in different parts of the microenvironment are examined. A simple predator-prey interaction illustrates the substantial effect of climate in modifying amount of time both prey and predator would be expected to be active simultaneously in the tropics vs a temperate desert. Comparisons are made between A. agama and the desert iguana, D. dorsalis for daily and seasonal maintenance requirements and their implications for seasonal changes in growth and reproductive potential.

  13. An annotated checklist of the lizards of French Guiana, mainly based on two recent collections

    NARCIS (Netherlands)

    Hoogmoed, M.S.; Lescure, J.

    1975-01-01

    At the moment 36 species of lizards (6 Gekkonidae, 12 Iguanidae, 1 Scincidae and 17 Teiidae) are known for certain to occur in French Guiana. Of these 36 species, four are reported from that country for the first time (Anolis marmoratus speciosus Garman, Cercosaura o. ocellata Wagler, Prionodactylus

  14. Tissue distribution and toxicity effects of myclobutanil enantiomers in lizards (Eremias argus).

    Science.gov (United States)

    Chen, Li; Li, Ruiting; Diao, Jinling; Tian, Zhongnan; Di, Shanshan; Zhang, Wenjun; Cheng, Cheng; Zhou, Zhiqiang

    2017-11-01

    In recent years, serious environmental pollution has caused a decrease in the abundance of many species worldwide. Reptiles are the most diverse group of terrestrial vertebrates. There are large amounts of toxicological data available regarding myclobutanil, but the adverse effects of myclobutanil on lizards has not been widely reported. In this study, treatment groups were orally administered a single-dose of myclobutanil (20mg/kg body weight (bw)). Subsequently, it was found that there were differences in myclobutanil levels between the different tissues and concentrations also changed with degradation time. The tissue concentrations of myclobutanil decreased in the order of: stomach > liver > lung > blood > testis > kidney > heart > brain. Based on our results, the liver and testis were considered to be the main target organs in lizards, indicating that the myclobutanil could induce potential hepatic and reproductive toxicity on lizards. Meanwhile, it was also demonstrated that the toxic effects of myclobutanil was different in different species, and the distribution of different pesticides in lizards were different. Copyright © 2017. Published by Elsevier Inc.

  15. Thermoregulatory Behavior in Diurnal Lizards as a Vehicle for Teaching Scientific Process

    Science.gov (United States)

    Platz, James E.

    2009-01-01

    Field experiments offer the opportunity for hands on experience with the scientific process. While this is true of a wide variety of activities, many have pitfalls both experimental and logistical that reduce the overall rate of success, in turn, influencing student learning outcomes. Relying on small, territorial, diurnal lizards and an array of…

  16. An Adaptive Neural Mechanism with a Lizard Ear Model for Binaural Acoustic Tracking

    DEFF Research Database (Denmark)

    Shaikh, Danish; Manoonpong, Poramate

    2016-01-01

    expensive algorithms. We present a novel bioinspired solution to acoustic tracking that uses only two microphones. The system is based on a neural mechanism coupled with a model of the peripheral auditory system of lizards. The peripheral auditory model provides sound direction information which the neural...

  17. Making Olympic lizards: the effects of specialised exercise training on performance.

    Science.gov (United States)

    Husak, Jerry F; Keith, Allison R; Wittry, Beth N

    2015-03-01

    Exercise training is well known to affect a suite of physiological and performance traits in mammals, but effects of training in other vertebrate tetrapod groups have been inconsistent. We examined performance and physiological differences among green anole lizards (Anolis carolinensis) that were trained for sprinting or endurance, using an increasingly rigorous training regimen over 8 weeks. Lizards trained for endurance had significantly higher post-training endurance capacity compared with the other treatment groups, but groups did not show post-training differences in sprint speed. Although acclimation to the laboratory environment and training explain some of our results, mechanistic explanations for these results correspond with the observed performance differences. After training, endurance-trained lizards had higher haematocrit and larger fast glycolytic muscle fibres. Despite no detectable change in maximal performance of sprint-trained lizards, we detected that they had significantly larger slow oxidative muscle fibre areas compared with the other treatments. Treatment groups did not differ in the proportion of number of fibre types, nor in the mass of most limb muscles or the heart. Our results offer some caveats for investigators conducting training research on non-model organisms and they reveal that muscle plasticity in response to training may be widespread phylogenetically. © 2015. Published by The Company of Biologists Ltd.

  18. Vitamin E Supplementation Increases the Attractiveness of Males' Scent for Female European Green Lizards

    Science.gov (United States)

    Kopena, Renáta; Martín, José; López, Pilar; Herczeg, Gábor

    2011-01-01

    Background In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis) have substantial amounts of α-tocopherol ( = vitamin E) in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown. Methodology/Principal Findings Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males' secretions were larger. Conclusions/Significance Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals. PMID:21552540

  19. Thermal sensitivity of cold climate lizards and the importance of distributional ranges.

    Science.gov (United States)

    Bonino, Marcelo F; Moreno Azócar, Débora L; Schulte, James A; Abdala, Cristian S; Cruz, Félix B

    2015-08-01

    One of the fundamental goals in macroecology is to understand the relationship among species' geographic ranges, ecophysiology, and climate; however, the mechanisms underlying the distributional geographic patterns observed remain unknown for most organisms. In the case of ectotherms this is particularly important because the knowledge of these interactions may provide a robust framework for predicting the potential consequences of climate change in these organisms. Here we studied the relationship of thermal sensitivity and thermal tolerance in Patagonian lizards and their geographic ranges, proposing that species with wider distributions have broader plasticity and thermal tolerance. We predicted that lizard thermal physiology is related to the thermal characteristics of the environment. We also explored the presence of trade-offs of some thermal traits and evaluated the potential effects of a predicted scenario of climate change for these species. We examined sixteen species of Liolaemini lizards from Patagonia representing species with different geographic range sizes. We obtained thermal tolerance data and performance curves for each species in laboratory trials. We found evidence supporting the idea that higher physiological plasticity allows species to achieve broader distribution ranges compared to species with restricted distributions. We also found a trade-off between broad levels of plasticity and higher optimum temperatures of performance. Finally, results from contrasting performance curves against the highest environmental temperatures that lizards may face in a future scenario (year 2080) suggest that the activity of species occurring at high latitudes may be unaffected by predicted climatic changes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. The Effects of Air Pressure on Spontaneous Otoacoustic Emissions of Lizards

    NARCIS (Netherlands)

    van Dijk, Pim; Manley, Geoffrey A.

    Small changes of air pressure outside the eardrum of five lizard species led to changes in frequency, level, and peak width of spontaneous otoacoustic emissions (SOAE). In contrast to humans, these changes generally occurred at very small pressures (<20 mbar). As in humans, SOAE amplitudes were

  1. Thermal and energetic constraints on ectotherm abundance: A global test using lizards

    Science.gov (United States)

    Buckley, L.B.; Rodda, G.H.; Jetz, W.

    2008-01-01

    Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population densities. Here we test simple bioenergetic models for an ecologically important group of ectothermic vertebrates by examining 483 lizard populations. We find that lizard population densities decrease as a power law of body mass with a slope approximately inverse to the slope of the relationship between metabolic rates and body mass. Energy availability should limit population densities. As predicted, environmental productivity has a positive effect on lizard density, strengthening the relationship between lizard density and body mass. In contrast, the effect of environmental temperature is at most weak due to behavioral thermoregulation, thermal evolution, or the temperature dependence of ectotherm performance. Our results provide initial insights into how energy needs and availability differentially constrain ectotherm and endotherm density across broad spatial scales. ?? 2008 by the Ecological Society of America.

  2. Fifty years of chasing lizards: new insights advance optimal escape theory.

    Science.gov (United States)

    Samia, Diogo S M; Blumstein, Daniel T; Stankowich, Theodore; Cooper, William E

    2016-05-01

    Systematic reviews and meta-analyses often examine data from diverse taxa to identify general patterns of effect sizes. Meta-analyses that focus on identifying generalisations in a single taxon are also valuable because species in a taxon are more likely to share similar unique constraints. We conducted a comprehensive phylogenetic meta-analysis of flight initiation distance in lizards. Flight initiation distance (FID) is a common metric used to quantify risk-taking and has previously been shown to reflect adaptive decision-making. The past decade has seen an explosion of studies focused on quantifying FID in lizards, and, because lizards occur in a wide range of habitats, are ecologically diverse, and are typically smaller and differ physiologically from the better studied mammals and birds, they are worthy of detailed examination. We found that variables that reflect the costs or benefits of flight (being engaged in social interactions, having food available) as well as certain predator effects (predator size and approach speed) had large effects on FID in the directions predicted by optimal escape theory. Variables that were associated with morphology (with the exception of crypsis) and physiology had relatively small effects, whereas habitat selection factors typically had moderate to large effect sizes. Lizards, like other taxa, are very sensitive to the costs of flight. © 2015 Cambridge Philosophical Society.

  3. Phylogenomic analyses of more than 4000 nuclear loci resolve the origin of snakes among lizard families.

    Science.gov (United States)

    Streicher, Jeffrey W; Wiens, John J

    2017-09-01

    Squamate reptiles (lizards and snakes) are the most diverse group of terrestrial vertebrates, with more than 10 000 species. Despite considerable effort to resolve relationships among major squamates clades, some branches have remained difficult. Among the most vexing has been the placement of snakes among lizard families, with most studies yielding only weak support for the position of snakes. Furthermore, the placement of iguanian lizards has remained controversial. Here we used targeted sequence capture to obtain data from 4178 nuclear loci from ultraconserved elements from 32 squamate taxa (and five outgroups) including representatives of all major squamate groups. Using both concatenated and species-tree methods, we recover strong support for a sister relationship between iguanian and anguimorph lizards, with snakes strongly supported as the sister group of these two clades. These analyses strongly resolve the difficult placement of snakes within squamates and show overwhelming support for the contentious position of iguanians. More generally, we provide a strongly supported hypothesis of higher-level relationships in the most species-rich tetrapod clade using coalescent-based species-tree methods and approximately 100 times more loci than previous estimates. © 2017 The Author(s).

  4. A body temperature model for lizards as estimated from the thermal environment

    NARCIS (Netherlands)

    Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Schlerf, M.; Toxopeus, A.G.; Overjijk, van S.; Bian, B.M.; Liu, Y.

    2012-01-01

    A physically based model was built to predict the transient body temperature of lizards in a thermally heterogeneous environment. Six heat transfer terms were taken into account in this model: solar radiation, convective heat flow, longwave radiation, conductive heat flow, metabolic heat gain and

  5. UV-deprived coloration reduces success in mate acquisition in male sand lizards (Lacerta agilis.

    Directory of Open Access Journals (Sweden)

    Mats Olsson

    Full Text Available Recent work on animal signals has revealed a wide occurrence of UV signals in tetrapods, in particular birds, but also in lizards (and perhaps other Squamate reptiles. Our previous work on the Swedish sand lizard (Lacerta agilis has verified, both in correlative selection analyses in the wild and with laboratory and field experiments, the importance of the green 'badge' on the body sides of adult males for securing mating opportunities, probably mostly through deterring rival males rather than attracting females. The role of UV in communication has, however, never been examined.Here we show that when measured immediately after spring skin shedding, there is also signaling in the UV. By UV-depriving the signal (reflectance with sun block chemicals fixated with permeable, harmless spray dressing, we show that males in the control group (spray dressing only had significantly higher success in mate acquisition than UV-deprived males.These results suggest that at least two colour traits in sand lizards, badge area and UV, contribute to rival deterrence and/or female choice on UV characters, which elevates success in mate acquisition in UV intact male sand lizards.

  6. A model for the relation between stimulus frequency and spontaneous otoacoustic emissions in lizard papillae

    NARCIS (Netherlands)

    Wit, Hero P.; van Dijk, Pim; Manley, Geoffrey A.

    2012-01-01

    Spontaneous otoacoustic emissions (SOAEs) and stimulus frequency otoacoustic emissions (SFOAEs) have been described from lizard ears. Although there are several models for these systems, none has modeled the characteristics of both of these types of otoacoustic emissions based upon their being

  7. Effects of oxygen on responses to heating in two lizard species sampled along an elevational gradient.

    Science.gov (United States)

    DuBois, P Mason; Shea, Tanner K; Claunch, Natalie M; Taylor, Emily N

    2017-08-01

    Thermal tolerance is an important variable in predictive models about the effects of global climate change on species distributions, yet the physiological mechanisms responsible for reduced performance at high temperatures in air-breathing vertebrates are not clear. We conducted an experiment to examine how oxygen affects three variables exhibited by ectotherms as they heat-gaping threshold, panting threshold, and loss of righting response (the latter indicating the critical thermal maximum)-in two lizard species along an elevational (and therefore environmental oxygen partial pressure) gradient. Oxygen partial pressure did not impact these variables in either species. We also exposed lizards at each elevation to severely hypoxic gas to evaluate their responses to hypoxia. Severely low oxygen partial pressure treatments significantly reduced the gaping threshold, panting threshold, and critical thermal maximum. Further, under these extreme hypoxic conditions, these variables were strongly and positively related to partial pressure of oxygen. In an elevation where both species overlapped, the thermal tolerance of the high elevation species was less affected by hypoxia than that of the low elevation species, suggesting the high elevation species may be adapted to lower oxygen partial pressures. In the high elevation species, female lizards had higher thermal tolerance than males. Our data suggest that oxygen impacts the thermal tolerance of lizards, but only under severely hypoxic conditions, possibly as a result of hypoxia-induced anapyrexia. Copyright © 2017. Published by Elsevier Ltd.

  8. Ecological explanations to island gigantism: dietary niche divergence, predation, and size in an endemic lizard.

    Science.gov (United States)

    Runemark, Anna; Sagonas, Kostas; Svensson, Erik I

    2015-08-01

    Although rapid evolution of body size on islands has long been known, the ecological mechanisms behind this island phenomenon remain poorly understood. Diet is an important selective pressure for morphological divergence. Here we investigate if selection for novel diets has contributed to the multiple independent cases of island gigantism in the Skyros wall lizard (Podarcis gaigeae) and if diet, predation, or both factors best explain island gigantism. We combined data on body size, shape, bite force, and realized and available diets to address this. Several lines of evidence suggest that diet has contributed to the island gigantism. The larger islet lizards have relatively wider heads and higher bite performance in relation to mainland lizards than would be expected from size differences alone. The proportions of consumed and available hard prey are higher on islets than mainland localities, and lizard body size is significantly correlated with the proportion of hard prey. Furthermore, the main axis of divergence in head shape is significantly correlated with dietary divergence. Finally, a model with only diet and one including diet and predation regime explain body size divergence equally well. Our results suggest that diet is an important ecological factor behind insular body size divergence, but could be consistent with an additional role for predation.

  9. Himantoglossum jankae (Orchidaceae: Orchideae), a new name for a long-misnamed lizard orchid

    NARCIS (Netherlands)

    Molnar, A.; Kreutz, C.A.J.; Ovari, M.; Sennikov, A.N.; Bateman, R.M.; Takacs, A.; Somlyay, L.; Sramko, G.

    2012-01-01

    A new name, Himantoglossum jankae, is given to the widely recognised lizard orchid species that is distributed primarily in the Balkan Peninsula and the northwestern region of Asia Minor and has been erroneously named H. caprinum in most previous literature. The new species differs from its closest

  10. Positive Relationship between Abdominal Coloration and Dermal Melanin Density in Phrynosomatid Lizards

    Science.gov (United States)

    Vanessa S. Quinn; Diana K. Hews

    2003-01-01

    Phrynosomatid lizards show considerable variation among species in the occurrence of a secondary sexual trait, blue abdominal coloration. The production of blue skin may be controlled by at least two cellular components, melanin in melanophores, and guanine in iridophores. To examine the hypothesis that a mechanism producing variation in abdominal coloration is...

  11. using agama lizard as a biomaker in heavy metal pollution monitoring

    African Journals Online (AJOL)

    Oyekunle

    Key words: Agama lizard, environmental pollution, soil, heavy metals, liver, kidney. ... Despite the considerable weight of evidence that exists in favour of the ..... bioaccumulation capacity of heavy metals by the kidney. (59.2 ± 15.3 µg/g) was ...

  12. Lizards of the genus Cnemidophorus from the Leeward Group and the adjacent mainland of South America

    NARCIS (Netherlands)

    Lammerée, Liesbeth

    1970-01-01

    When WAGENAAR HUMMELINCK (1940, p. 83—85) made a survey of the lizards of Curaçao, Aruba, Bonaire and the Venezuelan Islands, he could give no more than a short list of specimens collected, together with a few critical remarks, and a single table on “Variation in Cnemidophorus” based on 379

  13. Does the conceptus of the viviparous lizard Barisia imbricata imbricata participates in the regulation of progesterone production and the control of luteolysis?

    Science.gov (United States)

    Martínez-Torres, Martín; Salcedo-Álvarez, Martha; Alvarez-Rodríguez, Carmen; Cárdenas-León, Mario; Luis, Juana; Moreno-Fierros, Leticia

    2014-08-01

    It is generally accepted that progesterone is necessary to maintain gestation; however, the mechanisms that control the production of this steroid remain unknown. The corpus luteum has been assigned a central role in the maintenance of gestation based on its capacity to produce progesterone. A pseudopregnancy model was performed in a viviparous lizard, Barisia imbricata imbricata, to determine whether the absence of embryos would affect the pattern of progesterone production or the corpus luteum histology. Blood samples were obtained prior to ovulation and at 8, 16, and 24 weeks after ovulation (pseudopregnant and pregnant lizards), as well as one day after parturition (pregnant lizards) or 32 weeks after ovulation (pseudopregnant lizards). The corpus luteum was surgically removed one day after blood samples were obtained. Blood aliquots from nongravid females were obtained at similar timepoints. We found a significant reduction in plasma progesterone concentrations at 24 and 32 weeks post-ovulation in pseudopregnant lizards compared with those observed at similar times in intact pregnant lizards, whereas the progesterone levels in non-gestant lizards remained significantly lower than in either pseudopregnant or pregnant lizards. Moreover, we observed that the histological appearance of the corpus luteum from pseudogestational females (obtained 24 and 32 weeks post-ovulation) differed from the corpora lutea from lizards in late gestation and intact parturient lizards. These observations suggest that the conceptus participates in the regulation of progesterone production in late gestation and also in luteolysis control. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Inhibition of plasma butyrylcholinesterase activity in the lizard Gallotia galloti palmae by pesticides: a field study

    International Nuclear Information System (INIS)

    Sanchez-Hernandez, Juan C.; Carbonell, R.; Henriquez Perez, A.; Montealegre, M.; Gomez, L.

    2004-01-01

    A field study was performed to evaluate the effect of exposure to organophosphorus (OP) and carbamate (CB) pesticides on the lizard Gallotia galloti palmae. Butyrylcholinesterase (BChE) activity was measured in the plasma of 420 lizards collected from agricultural and reference areas on the Island of La Palma (Canary Islands, Spain) in two sampling periods. Exposure to cholinesterase-inhibiting pesticides was evaluated by a statistical criterion based on a threshold value (two standard deviations below the mean enzyme activity) calculated for the reference group, and a chemical criterion based on the in vitro reactivation of BChE activity using pyridine-2-aldoxime methochloride (2-PAM) or after water dilution of the sample. Mean (±SD) BChE activity for lizards from agricultural areas was significantly lower (Fuencaliente site = 2.00 ± 0.98 μmol min -1 ml -1 , Tazacorte site = 2.88 ± 1.08) than that for lizards from the reference areas (Los Llanos site = 3.06 ± 1.17 μmol min -1 ml -1 , Tigalate site = 3.96 ± 1.62). According to the statistical criterion, the number of lizards with BChE depressed was higher at Fuencaliente (22% of males and 25.4% of females) than that sampled at Tazacorte (7.8% of males and 6.2% of females). According to the chemical criterion, Fuencaliente also yielded a higher number of individuals (112 males and 47 females) with BChE activity inhibited by both OP and CB pesticides. CBs appeared to be the pesticides most responsible for BChE inhibition because most of the samples showed reactivation of BChE activity after water treatment (63.3% from Fuencaliente and 29% from Tazacorte). We concluded that the use of reactivation techniques on plasma BChE activity is a better and more accurate method for assessing field exposure to OP/CB pesticides in this lizard species than making direct comparisons of enzyme activity levels between sampling areas. - Capsule: Chemical reactivation of lizard BChE activity is a suitable diagnostic method for

  15. The Solid-Phase Synthesis of an Fe-N-C Electrocatalyst for High-Power Proton-Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Liu, Qingtao; Liu, Xiaofang; Zheng, Lirong; Shui, Jianglan

    2018-01-26

    The environmentally friendly synthesis of highly active Fe-N-C electrocatalysts for proton-exchange membrane fuel cells (PEMFCs) is desirable but remains challenging. A simple and scalable method is presented to fabricate Fe II -doped ZIF-8, which can be further pyrolyzed into Fe-N-C with 3 wt % of Fe exclusively in Fe-N 4 active moieties. Significantly, this Fe-N-C derived acidic PEMFC exhibits an unprecedented current density of 1.65 A cm -2 at 0.6 V and the highest power density of 1.14 W cm -2 compared with previously reported NPMCs. The excellent PEMFC performance can be attributed to the densely and atomically dispersed Fe-N 4 active moieties on the small and uniform catalyst nanoparticles. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards

    Directory of Open Access Journals (Sweden)

    Catarina C. Ferreira

    2016-06-01

    Full Text Available Background. Reptiles are sensitive to habitat disturbance induced by wildfires but species frequently show opposing responses. Functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, lizard species of Mediterranean affinity (Psammodromus algirus and Podarcis guadarramae increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberi and Podarcis bocagei decrease. Timon lepidus, the largest Mediterranean lizard in the region, shows mixed responses depending on the locality and fire history. We tested whether such interspecific differences are of a functional nature, namely, if ecophysiological traits may determine lizard response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that Mediterranean species, which increase density in open habitats promoted by frequent fire regimes, should be more thermophile and suffer lower water losses than Atlantic species. Methods. We submitted 6–10 adult males of the five species to standard experiments for assessing preferred body temperatures (Tp and evaporativewater loss rates (EWL, and examined the variation among species and along time by means of repeated-measures AN(COVAs. Results. Results only partially supported our initial expectations, since the medium-sized P. algirus clearly attained higher Tp and lower EWL. The two small wall lizards (P. bocagei and P. guadarramae displayed low Tp and high EWL while the two large green lizards (T. lepidus and L. schreiberi displayed intermediate values for both parameters. Discussion. The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered.

  17. DAQ application of PC oscilloscope for chaos fiber-optic fence system based on LabVIEW

    Science.gov (United States)

    Lu, Manman; Fang, Nian; Wang, Lutang; Huang, Zhaoming; Sun, Xiaofei

    2011-12-01

    In order to obtain simultaneously high sample rate and large buffer in data acquisition (DAQ) for a chaos fiber-optic fence system, we developed a double-channel high-speed DAQ application of a digital oscilloscope of PicoScope 5203 based on LabVIEW. We accomplished it by creating call library function (CLF) nodes to call the DAQ functions in the two dynamic link libraries (DLLs) of PS5000.dll and PS5000wrap.dll provided by Pico Technology Company. The maximum real-time sample rate of the DAQ application can reach 1GS/s. We can control the resolutions of the application at the sample time and data amplitudes by changing their units in the block diagram, and also control the start and end times of the sampling operations. The experimental results show that the application has enough high sample rate and large buffer to meet the demanding DAQ requirements of the chaos fiber-optic fence system.

  18. Original research papers. Kinematic Characterisation of the Lunge and the Fleche in Epee Fencing: Two Case Studies

    Directory of Open Access Journals (Sweden)

    Bober Tadeusz

    2016-12-01

    Full Text Available Introduction. The aim of this study was to characterise the whole body dynamics and upper and lower joint kinematics during two common fencing steps: the lunge and the fleche. Material and methods. Two male competitive epee fencers were studied. Kinematics data were collected at 120 Hz (BTS Smart system and ground reaction forces were measured at 120 Hz (Kistler platform. The resultant centre of gravity and end segment velocities were calculated. Temporal events were referenced to the horizontal ground reaction force. Time domain linear joint velocities were extracted. Results. At the whole-body level, the resultant centre of gravity velocity was higher during the fleche (2.64 and 2.89 m/s than during the lunge (1.94 and 2.21 m/s. At the joint level, the wrist and elbow attained their peak velocities earlier than the proximal joint for both the lunge and the fleche for both athletes. Conclusions. The sequence of peak segmental velocities followed a distal to proximal sequence for both fencing steps.

  19. Homology of the jaw muscles in lizards and snakes-a solution from a comparative gnathostome approach.

    Science.gov (United States)

    Johnston, Peter

    2014-03-01

    Homology or shared evolutionary origin of jaw adductor muscles in lizards and snakes has been difficult to establish, although snakes clearly arose within the lizard radiation. Lizards typically have temporal adductors layered lateral to medial, and in snakes the muscles are arranged in a rostral to caudal pattern. Recent work has suggested that the jaw adductor group in gnathostomes is arranged as a folded sheet; when this theory is applied to snakes, homology with lizard morphology can be seen. This conclusion revisits the work of S.B. McDowell, J Herpetol 1986; 20:353-407, who proposed that homology involves identity of m. levator anguli oris and the loss of m. adductor mandibulae externus profundus, at least in "advanced" (colubroid) snakes. Here I advance the folded sheet hypothesis across the whole snake tree using new and literature data, and provide a solution to this homology problem. Copyright © 2014 Wiley Periodicals, Inc.

  20. A study of secondary fabrics in rocks from the lizard Peninsula and adjacent areas in southwest cornwall, england

    Science.gov (United States)

    Rathore, Jaswant Singh

    1980-09-01

    Magnetic susceptibility anisotropy techniques were applied to samples taken in selected areas of the Lizard Peninsula in order to study secondary fabrics due to: (1) the intrusion of granites into sediments; (2) the compression in the sediments to the north of the Lizard thrust boundary; and (3) the intrusion of serpentine into hornblende schists of the Lizard metamorphic block. The magnetic fabric around the Carnmenellis and Godolphin granite masses shows a strong compressional fabric, tending to suggest that the Devonian sediments were compressed radially as the granites intruded them. The high degree of anisotropy observed at the Lizard boundary falls, with increasing distance from the thrust, systematically down to low values in the Devonian sediments. The distinct changes in the fabric parameters at the north end of Church Cove-Landewednack and the southern end of Cadgwith Cove appear to be the remnant secondary fabrics due to the intrusion of serpentine into hornblende schists.

  1. Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves

    OpenAIRE

    Klomp, D. A.; Stuart-Fox, D.; Das, I.; Ord, T. J.

    2014-01-01

    Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds...

  2. The effect of chronic seaweed subsidies on herbivory: plant-mediated fertilization pathway overshadows lizard-mediated predator pathways.

    Science.gov (United States)

    Piovia-Scott, Jonah; Spiller, David A; Takimoto, Gaku; Yang, Louie H; Wright, Amber N; Schoener, Thomas W

    2013-08-01

    Flows of energy and materials link ecosystems worldwide and have important consequences for the structure of ecological communities. While these resource subsidies typically enter recipient food webs through multiple channels, most previous studies focussed on a single pathway of resource input. We used path analysis to evaluate multiple pathways connecting chronic marine resource inputs (in the form of seaweed deposits) and herbivory in a shoreline terrestrial ecosystem. We found statistical support for a fertilization effect (seaweed increased foliar nitrogen content, leading to greater herbivory) and a lizard numerical response effect (seaweed increased lizard densities, leading to reduced herbivory), but not for a lizard diet-shift effect (seaweed increased the proportion of marine-derived prey in lizard diets, but lizard diet was not strongly associated with herbivory). Greater seaweed abundance was associated with greater herbivory, and the fertilization effect was larger than the combined lizard effects. Thus, the bottom-up, plant-mediated effect of fertilization on herbivory overshadowed the top-down effects of lizard predators. These results, from unmanipulated shoreline plots with persistent differences in chronic seaweed deposition, differ from those of a previous experimental study of the short-term effects of a pulse of seaweed deposition: while the increase in herbivory in response to chronic seaweed deposition was due to the fertilization effect, the short-term increase in herbivory in response to a pulse of seaweed deposition was due to the lizard diet-shift effect. This contrast highlights the importance of the temporal pattern of resource inputs in determining the mechanism of community response to resource subsidies.

  3. Pentastomid, Raillietiella mottae Almeida, Freire and Lopes, 2008, infecting lizards in an area of caatinga, northeast, Brazil

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    WO. Almeida

    Full Text Available Pentastomids can infect the respiratory tract of lizards, causing their death and as a result influencing the population size of hosts. Despite this, studies on rates of pulmonary infection of Brazilian lizards, including those living in Caatinga ecosystems of northeastern Brazil are scarce. Active collections of lizards were performed from October to December 2004 in an area of Caatinga of the Estação Experimental de São João do Cariri - EESJC (07º 25' S and 36º 30' W, located in the state of Paraíba, Northeast of Brazil. Forty-five lizards inhabiting granite outcrops in an area of Caatinga were captured, belonging to the following species: Tropidurus hispidus (Spix, 1825 (18 individuals, T. semitaeniatus (Spix, 1825 (15 individuals, Phyllopezus periosus Rodrigues, 1986 (6 individuals, and P. pollicaris (Spix, 1825 (6 individuals. Laboratory examination revealed that all species had some degree of pulmonary infection caused by Raillietiella mottae. The highest rates of prevalence (66.7% and mean intensity of infection (5.25 ± 2.01, range of 2-11 were observed in P. periosus. The results obtained in this study show that lizards of the Brazilian semi-arid region are infected by a generalist species of pentastomid. The most likely cause for such pattern is the similarity in lizards' diets (ants and termites. It is particularly noteworthy that T. semitaeniatus, P. periosus, and P. pollicaris represent new host records for R. mottae.

  4. Supplementation of male pheromone on rock substrates attracts female rock lizards to the territories of males: a field experiment.

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    José Martín

    Full Text Available Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field.In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas.These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display.

  5. Supplementation of Male Pheromone on Rock Substrates Attracts Female Rock Lizards to the Territories of Males: A Field Experiment

    Science.gov (United States)

    Martín, José; López, Pilar

    2012-01-01

    Background Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones) with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni) prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field. Methodology/Principal Findings In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas. Conclusions/Significance These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display. PMID:22253895

  6. The importance of ultraviolet and near-infrared sensitivity for visual discrimination in two species of lacertid lizards.

    Science.gov (United States)

    Martin, Mélissa; Le Galliard, Jean-François; Meylan, Sandrine; Loew, Ellis R

    2015-02-01

    Male and female Lacertid lizards often display conspicuous coloration that is involved in intraspecific communication. However, visual systems of Lacertidae have rarely been studied and the spectral sensitivity of their retinal photoreceptors remains unknown. Here, we characterise the spectral sensitivity of two Lacertid species from contrasting habitats: the wall lizard Podarcis muralis and the common lizard Zootoca vivipara. Both species possess a pure-cone retina with one spectral class of double cones and four spectral classes of single cones. The two species differ in the spectral sensitivity of the LWS cones, the relative abundance of UVS single cones (potentially more abundant in Z. vivipara) and the coloration of oil droplets. Wall lizards have pure vitamin A1-based photopigments, whereas common lizards possess mixed vitamin A1 and A2 photopigments, extending spectral sensitivity into the near infrared, which is a rare feature in terrestrial vertebrates. We found that spectral sensitivity in the UV and near infrared improves discrimination of small variations in throat coloration among Z. vivipara. Thus, retinal specialisations optimise chromatic resolution in common lizards, indicating that the visual system and visual signals might co-evolve. © 2015. Published by The Company of Biologists Ltd.

  7. Thermal preference, thermal tolerance and the thermal de-pendence of digestive performance in two Phrynocephalus lizards (Agamidae), with a review of species studied

    OpenAIRE

    Yanfu QU, Hong LI, Jianfang GAO, Xuefeng XU, Xiang JI

    2011-01-01

    We reported data on thermal preference, thermal tolerance and the thermal dependence of digestive performance for two Phrynocephalus lizards (P. frontalis and P. versicolor), and compared data among lizards so far studied worldwide. Mean values for selected body temperature (Tsel) and critical thermal maximum (CTMax) were greater in P. versicolor, whereas mean values for critical thermal minimum (CTMin) did not differ between the two species. The two lizards differed in food intake, but not i...

  8. Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus).

    Science.gov (United States)

    Regnault, Sophie; Jones, Marc E H; Pitsillides, Andrew A; Hutchinson, John R

    2016-05-01

    The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary

  9. Habitat relationships of reptiles in pine beetle disturbed forests of Alabama, U.S.A., with guidelines for a modified drift-fence sampling method

    Science.gov (United States)

    William B. Sutton; Yong Wang; Callie J. Schweitzer

    2010-01-01

    Understanding vertebrate habitat relationships is important to promote management strategies for the longterm conservation of many species. Using a modified drift fence method, we sampled reptiles and compared habitat variables within the William B. Bankhead National Forest (BNF) in Alabama, U.S.A from April 2005 to June 2006. We captured 226 individual reptiles...

  10. Gliding lizards use the position of the sun to enhance social display.

    Science.gov (United States)

    Klomp, Danielle A; Stuart-Fox, Devi; Das, Indraneil; Ord, Terry J

    2017-02-01

    Effective communication requires animal signals to be readily detected by receivers in the environments in which they are typically given. Certain light conditions enhance the visibility of colour signals and these conditions can vary depending on the orientation of the sun and the position of the signaller. We tested whether Draco sumatranus gliding lizards modified their position relative to the sun to enhance the conspicuousness of their throat-fan (dewlap) during social display to conspecifics. The dewlap was translucent, and we found that lizards were significantly more likely to orient themselves perpendicular to the sun when displaying. This increases the dewlap's radiance, and likely, its conspicuousness, by increasing the amount of light transmitted through the ornament. This is a rare example of a behavioural adaptation for enhancing the visibility of an ornament to distant receivers. © 2017 The Author(s).

  11. Characterisation of major histocompatibility complex class I transcripts in an Australian dragon lizard.

    Science.gov (United States)

    Hacking, Jessica; Bertozzi, Terry; Moussalli, Adnan; Bradford, Tessa; Gardner, Michael

    2018-07-01

    Characterisation of squamate major histocompatibility complex (MHC) genes has lagged behind other taxonomic groups. MHC genes encode cell-surface glycoproteins that present self- and pathogen-derived peptides to T cells and play a critical role in pathogen recognition. Here we characterise MHC class I transcripts for an agamid lizard (Ctenophorus decresii) and investigate the evolution of MHC class I in Iguanian lizards. An iterative assembly strategy was used to identify six full-length C. decresii MHC class I transcripts, which were validated as likely to encode classical class I MHC molecules. Evidence for exon shuffling recombination was uncovered for C. decresii transcripts and Bayesian phylogenetic analysis of Iguanian MHC class I sequences revealed a pattern expected under a birth-and-death mode of evolution. This work provides a stepping stone towards further research on the agamid MHC class I region. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Erosion of lizard diversity by climate change and altered thermal niches.

    Science.gov (United States)

    Sinervo, Barry; Méndez-de-la-Cruz, Fausto; Miles, Donald B; Heulin, Benoit; Bastiaans, Elizabeth; Villagrán-Santa Cruz, Maricela; Lara-Resendiz, Rafael; Martínez-Méndez, Norberto; Calderón-Espinosa, Martha Lucía; Meza-Lázaro, Rubi Nelsi; Gadsden, Héctor; Avila, Luciano Javier; Morando, Mariana; De la Riva, Ignacio J; Victoriano Sepulveda, Pedro; Rocha, Carlos Frederico Duarte; Ibargüengoytía, Nora; Aguilar Puntriano, César; Massot, Manuel; Lepetz, Virginie; Oksanen, Tuula A; Chapple, David G; Bauer, Aaron M; Branch, William R; Clobert, Jean; Sites, Jack W

    2010-05-14

    It is predicted that climate change will cause species extinctions and distributional shifts in coming decades, but data to validate these predictions are relatively scarce. Here, we compare recent and historical surveys for 48 Mexican lizard species at 200 sites. Since 1975, 12% of local populations have gone extinct. We verified physiological models of extinction risk with observed local extinctions and extended projections worldwide. Since 1975, we estimate that 4% of local populations have gone extinct worldwide, but by 2080 local extinctions are projected to reach 39% worldwide, and species extinctions may reach 20%. Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change.

  13. Methods and pitfalls of measuring thermal preference and tolerance in lizards.

    Science.gov (United States)

    Camacho, Agustín; Rusch, Travis W

    2017-08-01

    Understanding methodological and biological sources of bias during the measurement of thermal parameters is essential for the advancement of thermal biology. For more than a century, studies on lizards have deepened our understanding of thermal ecophysiology, employing multiple methods to measure thermal preferences and tolerances. We reviewed 129 articles concerned with measuring preferred body temperature (PBT), voluntary thermal tolerance, and critical temperatures of lizards to offer: a) an overview of the methods used to measure and report these parameters, b) a summary of the methodological and biological factors affecting thermal preference and tolerance, c) recommendations to avoid identified pitfalls, and d) directions for continued progress in our application and understanding of these thermal parameters. We emphasize the need for more methodological and comparative studies. Lastly, we urge researchers to provide more detailed methodological descriptions and suggest ways to make their raw data more informative to increase the utility of thermal biology studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A revised key to the lizards of Iran (Reptilia: Squamata: Lacertilia).

    Science.gov (United States)

    Nasrabadi, Reza; Rastegar-Pouyani, Nasrullah; Rastegar-Pouyani, Eskandar; Gharzi, Ahmad

    2017-02-03

    During recent years several lizard taxa have been added to the faunal list of Iran. Descriptions and new records are scattered in different publications in the herpetological literature. We here present species accounts for 152 species belonging to 43 genera and 10 families up to July 2016. The most diverse family is Lacertidae with 9 genera, 49 species and 2 subspecies, followed by Gekkonidae with 13 genera and 43 species, Agamidae with 5 genera, 18 species and 4 subspecies, Scincidae with 7 genera, 18 species and 2 subspecies, Phyllodactylidae with 1 genus and 10 species, Sphaerodactylidae with 2 genera and 4 species, Varanidae with 1 genus, 3 species and 2 subspecies, Uromastycidae with 2 genera and 3 species, Eublepharidae with 1 genus and 3 species, and Anguidae with 2 genera and 2 species. The current paper provides a dichotomous key including all of the currently recognized lizards of Iran.

  15. Lung infection rates in two sympatric Tropiduridae lizard species by pentastomids and nematodes in northeastern Brazil

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    WO. Almeida

    Full Text Available We present data on pulmonary infection rates by parasites in the lizards Tropidurus hispidus Spix, 1825 and T. semitaeniatus (Spix, 1825 living sympatrically in the Chapada do Araripe mountain Range, northeastern Brazil. We found no parasite pulmonary infection in T. semitaeniatus. However, two pulmonary parasite species were found in the T. hispidus hosts, the pentastomid Raillietiella mottae Almeida, Freire and Lopes, 2008 and the nematode Rhabdias sp. Overall prevalence was 5%. Prevalence of R. mottae was 2.5% and corresponded to only one parasite on each infected host. Prevalence of Rhabdias sp. was 2.5% and the range of infection was 1-2 parasites per host. This represents the first record of Rhabdias infecting lizards of the family Tropiduridae in the Neotropical region. Furthermore, we present a comparison of parameters of infection by pulmonary parasites including some recent studies in Brazil.

  16. Soft tissue preservation in a fossil marine lizard with a bilobed tail fin.

    Science.gov (United States)

    Lindgren, Johan; Kaddumi, Hani F; Polcyn, Michael J

    2013-01-01

    Mosasaurs are secondarily aquatic squamates that became the dominant marine reptiles in the Late Cretaceous about 98-66 million years ago. Although early members of the group possessed body shapes similar to extant monitor lizards, derived forms have traditionally been portrayed as long, sleek animals with broadened, yet ultimately tapering tails. Here we report an extraordinary mosasaur fossil from the Maastrichtian of Harrana in central Jordan, which preserves soft tissues, including high fidelity outlines of a caudal fluke and flippers. This specimen provides the first indisputable evidence that derived mosasaurs were propelled by hypocercal tail fins, a hypothesis that was previously based on comparative skeletal anatomy alone. Ecomorphological comparisons suggest that derived mosasaurs were similar to pelagic sharks in terms of swimming performance, a finding that significantly expands our understanding of the level of aquatic adaptation achieved by these seagoing lizards.

  17. Helminths infecting the parthenogenetic whiptail lizard Cnemidophorus nativo in a restinga habitat of Bahia State, Brazil.

    Science.gov (United States)

    Menezes, V A; Vrcibradic, D; Vicente, J J; Dutra, G F; Rocha, C F D

    2004-12-01

    A sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.

  18. Prevalence and molecular identification of Cryptosporidium isolates from pet lizards and snakes in Italy

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    Rinaldi L.

    2012-11-01

    Full Text Available In order to acquire prevalence and genetic data on Cryptosporidium infections in captive lizards and snakes kept as pets, a survey was conducted on 150 individual reptiles from southern Italy. Fecal samples were preserved in 5% formalin and analyzed using a commercial immunofluorescence assay (IFA for the detection of Cryptosporidium oocysts and Giardia cysts. IFA revealed the presence of Cryptosporidium oocysts in nine of the 150 samples examined (6.0%, precisely in 6/125 snakes (4.8% and in 3/25 lizards (12.0%; all fecal samples tested negative for the presence of Giardia cysts. Molecular characterization based on nested PCR amplification and sequencing of the SSU-rRNA gene, revealed the presence of Cryptosporidium serpentis in three samples from snakes (Boa constrictor constrictor, Elapheguttata guttata guttata and Python molurus.

  19. Immune activation affects chemical sexual ornaments of male Iberian wall lizards

    Science.gov (United States)

    López, Pilar; Gabirot, Marianne; Martín, José

    2009-01-01

    Many animals use chemical signals in sexual selection, but it is not clear how these sexual traits might have evolved to signal honestly male condition. It is possible that there is a trade-off between maintaining the immune system and the elaboration of ornaments. We experimentally challenged the immune system of male Iberian wall lizards, Podarcis hispanica, with a bacterial antigen (lipopolysaccharide), without pathogenic effects, to explore whether the immune activation affected chemical ornaments. Immune activation resulted in decreased proportions of a major chemical in femoral secretions (cholesta-5,7-dien-3-ol = provitamin D3) known to be selected in scent of males by females and which active form (vitamin D) has a variety of important effects on immune system function. This result suggests the existence of a potential trade-off between physiological regulation of the immune system and the allocation of essential nutrients (vitamins) to sexual chemical ornaments in male lizards.

  20. Ultrasonic-assisted extraction of phenolic and antioxidative compounds from lizard tail (Houttuynia cordata Thunb.

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    Trakul Prommajak

    2014-02-01

    Full Text Available Lizard tail (Houttuynia cordata Thunb. is an Asian herb which has many biological activities, including antioxidative property from polyphenolic compounds. Response surface methodology and Box-Behnken design were employed to study the effect of extraction temperature (30 to 70°C, extraction time (10 to 30 min, ethanol concentration (30 to 70%, and solvent to sample ratio (2 to 6 ml/g on ultrasonic-assisted extraction of phenolic compounds from lizard tail and antioxidant capacity of the herb extract. Extraction temperature was the most relevant factor on the responses. Optimal condition was the extraction temperature of 70°C for 30 min, using 60% ethanol concentration at the solvent to sample ratio of 5 ml/g. Model adequacies were confirmed by extraction at the optimal condition and normality of standardized residuals.

  1. Physiological Correlates of Multiple Parasitic Infections in Side-Blotched Lizards.

    Science.gov (United States)

    Spence, Austin R; Durso, Andrew M; Smith, Geoffrey D; Skinner, Heather M; French, Susannah S

    We investigated the presence of ectoparasites and hemoparasites in side-blotched lizards (Uta stansburiana) across a large part of their range and measured how parasitic infection related to several key physiological indicators of health. Blood samples were collected from 132 lizards from central Arizona, southern Utah, and eastern Oregon. Hemoparasites were found in 22 individuals (3.2% prevalence in Arizona, 19.1% in Utah, and 6.3% in Oregon), and ectoparasites were found on 51 individuals (56.3% prevalence in Arizona, 56.1% in Utah, and 6.7% in Oregon), with 11 individuals infected with both. Hemoparasites and ectoparasites were found in all three states. Immunocompetence was higher in individuals infected with both hemoparasites and ectoparasites. Body condition, glucocorticoid levels, and reproductive investment were not related to infection status. Our study provides evidence that parasitic infection is associated with an active immune system in wild reptiles but may not impose other costs usually associated with parasites.

  2. Checklist of helminths from lizards and amphisbaenians (Reptilia, Squamata of South America

    Directory of Open Access Journals (Sweden)

    RW Ávila

    2010-01-01

    Full Text Available A comprehensive and up to date summary of the literature on the helminth parasites of lizards and amphisbaenians from South America is herein presented. One-hundred eighteen lizard species from twelve countries were reported in the literature harboring a total of 155 helminth species, being none acanthocephalans, 15 cestodes, 20 trematodes and 111 nematodes. Of these, one record was from Chile and French Guiana, three from Colombia, three from Uruguay, eight from Bolivia, nine from Surinam, 13 from Paraguay, 12 from Venezuela, 27 from Ecuador, 17 from Argentina, 39 from Peru and 103 from Brazil. The present list provides host, geographical distribution (with the respective biome, when possible, site of infection and references from the parasites. A systematic parasite-host list is also provided.

  3. From tameness to wariness: chemical recognition of snake predators by lizards in a Mediterranean island

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    Abraham Mencía

    2017-01-01

    Full Text Available Antipredatory defenses are maintained when benefit exceeds cost. A weak predation pressure may lead insular lizards to tameness. Podarcis lilfordi exhibits a high degree of insular tameness, which may explain its extinction from the main island of Menorca when humans introduced predators. There are three species of lizards in Menorca: the native P. lilfordi, only on the surrounding islets, and two introduced lizards in the main island, Scelarcis perspicillata and Podarcis siculus. In addition, there are three species of snakes, all introduced: one non-saurophagous (Natrix maura, one potentially non-saurophagous (Rhinechis scalaris and one saurophagous (Macroprotodon mauritanicus. We studied the reaction to snake chemical cues in five populations: (1 P. lilfordi of Colom, (2 P. lilfordi of Aire, (3 P. lilfordi of Binicodrell, (4 S. perspicillata, and (5 P. siculus, ordered by increasing level of predation pressure. The three snakes are present in the main island, while only R. scalaris is present in Colom islet, Aire and Binicodrell being snake-free islets. We aimed to assess the relationship between predation pressure and the degree of insular tameness regarding scent recognition. We hypothesized that P. lilfordi should show the highest degree of tameness, S. perspicillata should show intermediate responses, and P. siculus should show the highest wariness. Results are clear: neither P. lilfordi nor S. perspicillata recognize any of the snakes, while P. siculus recognizes the scent of M. mauritanicus and reacts to it with typical well-defined antipredatory behaviours as tail waving and slow motion. These results rise questions about the loss of chemical recognition of predators during island tameness and its related costs and benefits for lizards of insular habitats. In addition, this highlights the necessity for strong conservation measures to avoid the introduction of alien predators.

  4. Dispersal and population state of an endangered island lizard following a conservation translocation.

    Science.gov (United States)

    Angeli, Nicole F; Lundgren, Ian F; Pollock, Clayton G; Hillis-Starr, Zandy M; Fitzgerald, Lee A

    2018-03-01

    Population size is widely used as a unit of ecological analysis, yet to estimate population size requires accounting for observed and latent heterogeneity influencing dispersion of individuals across landscapes. In newly established populations, such as when animals are translocated for conservation, dispersal and availability of resources influence patterns of abundance. We developed a process to estimate population size using N-mixture models and spatial models for newly established and dispersing populations. We used our approach to estimate the population size of critically endangered St. Croix ground lizards (Ameiva polops) five years after translocation of 57 individuals to Buck Island, an offshore island of St. Croix, United States Virgin Islands. Estimates of population size incorporated abiotic variables, dispersal limits, and operative environmental temperature available to the lizards to account for low species detection. Operative environmental temperature and distance from the translocation site were always important in fitting the N-mixture model indicating effects of dispersal and species biology on estimates of population size. We found that the population is increasing its range across the island by 5-10% every six months. We spatially interpolated site-specific abundance from the N-mixture model to the entire island, and we estimated 1,473 (95% CI, 940-1,802) St. Croix ground lizards on Buck Island in 2013 corresponding to survey results. This represents a 26-fold increase since the translocation. We predicted the future dispersal of the lizards to all habitats on Buck Island, with the potential for the population to increase by another five times in the future. Incorporating biologically relevant covariates as explicit parameters in population models can improve predictions of population size and the future spread of species introduced to new localities. © 2018 by the Ecological Society of America.

  5. The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus

    OpenAIRE

    Vitt, Laurie J.; Caldwell, Janalee P.; Zani, Peter A.; Titus, Tom A.

    1997-01-01

    We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed alo...

  6. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards.

    Science.gov (United States)

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang; Baumgartner, Werner

    2011-01-01

    Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive - and for Phrynosoma directed - transport of water.

  7. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

    Directory of Open Access Journals (Sweden)

    Philipp Comanns

    2011-04-01

    Full Text Available Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus, the Arabian toadhead agama (Phrynocephalus arabicus and the Texas horned lizard (Phrynosoma cornutum. All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water.

  8. Correlated evolution of herbivory and food chemical discrimination in iguanian and ambush foraging lizards

    OpenAIRE

    William E. Cooper

    2003-01-01

    To efficiently locate and assess foods, animal sensory capacities and behavioral discriminations based on them must be appropriate for the diet and method of hunting. In lizards, actively foraging insectivores identify animal prey using lingually sampled chemical cues, but ambush foragers do not. Among plant eaters derived from active foragers, plant chemical discrimination is added to prey chemical discrimination, resulting in correlated evolution of plant diet and plant chemical discriminat...

  9. The hematology of captive Bobtail lizards (Tiliqua rugosa): blood counts, light microscopy, cytochemistry, and ultrastructure.

    Science.gov (United States)

    Moller, Cheryl A; Gaál, Tibor; Mills, Jennifer N

    2016-12-01

    Bobtail lizards (Tiliqua rugosa) are native to Australia. The only previous study on the hematology of this species documented just 6 animals. The aims of this study were to characterize the light microscopy, ultrastructure and cytochemistry of blood cells, and evaluate CBCs of captive Bobtail lizards. Over 2 consecutive summers, heparinized venous blood was collected from the ventral coccygeal vein of 46 clinically healthy, captive indoor- or outdoor-housed adult Bobtails. Complete blood cell counts and smear evaluations were performed, and cytochemical stains and transmission electron microscopy were used to further characterize blood cells. The eosinophils of this species were uniformly vacuolated: a unique feature not previously reported in reptiles. Heterophils were the predominant leukocyte, with fewer lymphocytes, azurophilic and nonazurophilic monocytes, occasional eosinophils, and basophils. Thrombocytes were frequently clumped. Slight polychromasia (0-15% of erythrocytes) was typically present. Hemogregarine parasites were seen on some smears. The range of CBC results was often wide. The PCV ranged from 11% to 38%. Total plasma proteins by refractometry were between 3.5 and 7.8 g/dL. Hemoglobin ranged between 2.6 and 12.6 g/dL by the modified hemoglobin-hydroxylamine method. Manual RBC count was 0.35-1.27 × 10 6 /μL, and WBC count was 2.86-22.66 × 10 3 /μL. Bobtail lizards housed outdoors had lower PCVs than indoor-housed animals. Bobtails with hemogregarine infections had lower PCVs than noninfected lizards. Ranges for CBC data were often very wide, influenced by preanalytic and analytic factors. Hemogregarine infection is associated with a decreased PCV, suggesting that some hemogregarine species are pathogenic in this population. © 2016 American Society for Veterinary Clinical Pathology.

  10. From tameness to wariness: chemical recognition of snake predators by lizards in a Mediterranean island

    Science.gov (United States)

    Pérez-Mellado, Valentín

    2017-01-01

    Antipredatory defenses are maintained when benefit exceeds cost. A weak predation pressure may lead insular lizards to tameness. Podarcis lilfordi exhibits a high degree of insular tameness, which may explain its extinction from the main island of Menorca when humans introduced predators. There are three species of lizards in Menorca: the native P. lilfordi, only on the surrounding islets, and two introduced lizards in the main island, Scelarcis perspicillata and Podarcis siculus. In addition, there are three species of snakes, all introduced: one non-saurophagous (Natrix maura), one potentially non-saurophagous (Rhinechis scalaris) and one saurophagous (Macroprotodon mauritanicus). We studied the reaction to snake chemical cues in five populations: (1) P. lilfordi of Colom, (2) P. lilfordi of Aire, (3) P. lilfordi of Binicodrell, (4) S. perspicillata, and (5) P. siculus, ordered by increasing level of predation pressure. The three snakes are present in the main island, while only R. scalaris is present in Colom islet, Aire and Binicodrell being snake-free islets. We aimed to assess the relationship between predation pressure and the degree of insular tameness regarding scent recognition. We hypothesized that P. lilfordi should show the highest degree of tameness, S. perspicillata should show intermediate responses, and P. siculus should show the highest wariness. Results are clear: neither P. lilfordi nor S. perspicillata recognize any of the snakes, while P. siculus recognizes the scent of M. mauritanicus and reacts to it with typical well-defined antipredatory behaviours as tail waving and slow motion. These results rise questions about the loss of chemical recognition of predators during island tameness and its related costs and benefits for lizards of insular habitats. In addition, this highlights the necessity for strong conservation measures to avoid the introduction of alien predators. PMID:28123905

  11. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

    Science.gov (United States)

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang

    2011-01-01

    Summary Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water. PMID:21977432

  12. Little dragons prefer flowers to maidens: a lizard that laps nectar and pollinates trees

    OpenAIRE

    Sazima, Ivan; Sazima, Cristina; Sazima, Marlies

    2005-01-01

    Lizards rarely visit and pollinate flowers, the few recent records being mostly restricted to island habitats. We report here on the Noronha skink (Euprepis atlanticus) seeking nectar in the flowers of the leguminous mulungu tree (Erythrina velutina) at Fernando de Noronha Archipelago, off northeast Brazil. The mulungu tree blooms during the dry season, and each flower secretes copious and diluted nectar throughout the day. The Noronha skink climbs up to the inflorescences and laps the nectar...

  13. Long-term changes in abundances of Sonoran Desert lizards reveal complex responses to climatic variation.

    Science.gov (United States)

    Flesch, Aaron D; Rosen, Philip C; Holm, Peter

    2017-12-01

    Understanding how climatic variation affects animal populations and communities is essential for addressing threats posed by climate change, especially in systems where impacts are projected to be high. We evaluated abundance dynamics of five common species of diurnal lizards over 25 years in a Sonoran Desert transition zone where precipitation decreased and temperature increased across time, and assessed hypotheses for the influence of climatic flux on spatiotemporal variation in abundances. We repeatedly surveyed lizards in spring and summer of each year at up to 32 sites, and used hierarchical mixture models to estimate detection probabilities, abundances, and population growth rates. Among terrestrial species, abundances of a short-lived, winter-spring breeder increased markedly by an estimated 237%-285% across time, while two larger spring-summer breeders with higher thermal preferences declined by up to 64%. Abundances of two arboreal species that occupy shaded and thus sheltered microhabitats fluctuated but did not decline systematically. Abundances of all species increased with precipitation at short lag times (1-1.5 years) likely due to enhanced food availability, but often declined after periods of high precipitation at longer lag times (2-4 years) likely due to predation and other biotic pressures. Although rising maximum daily temperatures (T max ) are expected to drive global declines of lizards, associations with T max were variable and weak for most species. Instead, abundances of all species declined with rising daily minimum temperatures, suggesting degradation of cool refugia imposed widespread metabolic or other costs. Our results suggest climate warming and drying are having major impacts on lizard communities by driving declines in species with traits that augment exposure to abiotic extremes and by modifying species interactions. The complexity of patterns we report indicates that evaluating and responding to the influence of climate change

  14. Omnivory of an Insular Lizard: Sources of Variation in the Diet of Podarcis lilfordi (Squamata, Lacertidae.

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    Ana Pérez-Cembranos

    Full Text Available Through 17 years and from a sample of 7,790 faecal pellets and 26,346 prey items, we studied the diet of the Balearic lizard Podarcis lilfordi in Aire Island (Menorca, Balearic Islands, Spain. We analysed the diet in terms of prey frequencies, as well as by their volume and biomass contributions. The diet of the Balearic lizard was extremely variable through the years, months and areas under study. The dominance of small clumped prey, particularly ants, was confirmed. However, the main contribution by volume corresponded to beetles, with a relevant role for Diplopoda and terrestrial Isopoda during some months and at particular areas of the island. Several prey items were probably captured at the base of shrubs, under stones or inside rock crevices. Therefore, our estimations of electivity would only be reliable for epigeal and flying prey. The capacity of the Balearic lizard to include marine subsidies in its diet, such as coastal crustaceans, is noteworthy. Also, its consumption of carrion from carcasses of gulls and rabbits and leftovers from human visitors is remarkable. Juvenile conspecifics can also be a sporadic food resource, especially during the second half of summer, whereas the consumption of vegetal matter is constant for each whole year. The shifts of vegetal exploitation among areas of the island and months take place according to availability of different plant species at each area or during a given period. Thus, lizards are able to conduct a thorough monitoring of plant phenology, exploiting a large variety of plant species. Omnivory does not imply the indiscriminate inclusion of any edible food in its diet. Rather, the inclusion of several food items means the adoption of a wide range of foraging behaviours adapted to the exploitation of each food resource.

  15. Omnivory of an Insular Lizard: Sources of Variation in the Diet of Podarcis lilfordi (Squamata, Lacertidae).

    Science.gov (United States)

    Pérez-Cembranos, Ana; León, Alicia; Pérez-Mellado, Valentín

    2016-01-01

    Through 17 years and from a sample of 7,790 faecal pellets and 26,346 prey items, we studied the diet of the Balearic lizard Podarcis lilfordi in Aire Island (Menorca, Balearic Islands, Spain). We analysed the diet in terms of prey frequencies, as well as by their volume and biomass contributions. The diet of the Balearic lizard was extremely variable through the years, months and areas under study. The dominance of small clumped prey, particularly ants, was confirmed. However, the main contribution by volume corresponded to beetles, with a relevant role for Diplopoda and terrestrial Isopoda during some months and at particular areas of the island. Several prey items were probably captured at the base of shrubs, under stones or inside rock crevices. Therefore, our estimations of electivity would only be reliable for epigeal and flying prey. The capacity of the Balearic lizard to include marine subsidies in its diet, such as coastal crustaceans, is noteworthy. Also, its consumption of carrion from carcasses of gulls and rabbits and leftovers from human visitors is remarkable. Juvenile conspecifics can also be a sporadic food resource, especially during the second half of summer, whereas the consumption of vegetal matter is constant for each whole year. The shifts of vegetal exploitation among areas of the island and months take place according to availability of different plant species at each area or during a given period. Thus, lizards are able to conduct a thorough monitoring of plant phenology, exploiting a large variety of plant species. Omnivory does not imply the indiscriminate inclusion of any edible food in its diet. Rather, the inclusion of several food items means the adoption of a wide range of foraging behaviours adapted to the exploitation of each food resource.

  16. Terminal distribution of retinal fibers in the tegu lizard (Tupinambis nigropunctatus).

    Science.gov (United States)

    Ebbesson, S O; Karten, H J

    1981-01-01

    The retinal projections in the tegu lizard were traced using degeneration-silver methods. Bilateral projections were found to the dorsolateral geniculate and the posterodorsal nuclei. Unilateral, crossed projections were traced to the suprachiasmatic nucleus, the ventrolateral geniculate nucleus, the mesencephalic lentiform nucleus, nucleus geniculatus praetectalis, the ectomammillary nucleus, and the optic tectum. Some of these connections are distinctly different from those reported in other reptiles and suggest that important interspecific variations occur among reptiles.

  17. Is the number and size of scales in Liolaemus lizards driven by climate?

    Science.gov (United States)

    José Tulli, María; Cruz, Félix B

    2018-05-03

    Ectothermic vertebrates are sensitive to thermal fluctuations in the environments where they occur. To buffer these fluctuations, ectotherms use different strategies, including the integument, which is a barrier that minimizes temperature exchange between the inner body and the surrounding air. In lizards, this barrier is constituted by keratinized scales of variable size, shape and texture, and its main function is protection, water loss avoidance and thermoregulation. The size of scales in lizards has been proposed to vary in relation to climatic gradients; however, it has also been observed that in some groups of Iguanian lizards could be related to phylogeny. Thus, here, we studied the area and number of scales (dorsal and ventral) of 61 species of Liolaemus lizards distributed in a broad latitudinal and altitudinal gradient to determine the nature of the variation of the scales with climate, and found that the number and size of scales are related to climatic variables, such as temperature and geographical variables as altitude. The evolutionary process that better explained how these morphological variables evolved was the Ornstein-Uhlenbeck model. The number of scales seemed to be related to common ancestry, whereas dorsal and ventral scale areas seemed to vary as a consequence of ecological traits. In fact, the ventral area is less exposed to climate conditions such as ultraviolet radiation or wind and is thus under less pressure to change in response to alterations in external conditions. It is possible that scale ornamentation such as keels and granulosity may bring some more information in this regard. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Elevational variation in body-temperature response to immune challenge in a lizard

    Directory of Open Access Journals (Sweden)

    Francisco Javier Zamora-Camacho

    2016-04-01

    Full Text Available Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1 hypothermia would be very costly, as the temporal window for reproduction is extremely small, and (2 fever would have a prohibitive cost, as heat acquisition is limited in such habitat. However, in temperate habitats, immune-challenged ectotherms might show a febrile response, due to lower cost/benefit balance as a consequence of a more suitable thermal environment. We tested this hypothesis in Psammodromus algirus lizards from Sierra Nevada (SE Spain, by testing body temperature preferred by alpine and non-alpine lizards, before and after activating their immune system with a typical innocuous pyrogen. Surprisingly, non-alpine lizards responded to immune challenge by decreasing preferential body-temperature, presumably allowing them to save energy and reduce exposure to predators. On the contrary, as predicted, immune-challenged alpine lizards maintained their body-temperature preferences. These results match with increased costs of no thermoregulation with elevation, due to the reduced window of time for reproduction in alpine environment.

  19. The importance of habitat resistance for movement decisions in the common lizard, Lacerta vivipara

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    Zajitschek Susanne RK

    2012-07-01

    Full Text Available Abstract Background Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara. We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested. Results We find that movement behaviour depends on the starting conditions, the physical properties of the dispersal corridor, and on the individuals’ phenotype. Specifically, the presence of cover and substrate providing suitable traction in the corridor had positive effects on individual movement decisions. Additionally, we find high phenotypic variation in the propensity to move dependent on the presence of cover. Individual back patterns also strongly affected movement decisions in interaction with the physical properties of the dispersal corridor. Conclusions Our results highlight the importance of understanding the habitat resistance for movement patterns, with humid habitats with covering vegetation providing the best conditions to initiate movement in the common lizard. In addition, population effects, differences in back pattern phenotype and individual plasticity were identified as key parameters influencing movement behaviour.

  20. Life on the rocks: habitat use drives morphological and performance evolution in lizards.

    Science.gov (United States)

    Goodman, Brett A; Miles, Donald B; Schwarzkopf, Lin

    2008-12-01

    As a group, lizards occupy a vast array of habitats worldwide, yet there remain relatively few cases where habitat use (ecology), morphology, and thus, performance, are clearly related. The best known examples include: increased limb length in response to increased arboreal perch diameter in anoles and increased limb length in response to increased habitat openness for some skinks. Rocky habitats impose strong natural selection on specific morphological characteristics, which differs from that imposed on terrestrial species, because moving about on inclined substrates of irregular sizes and shapes constrains locomotor performance in predictable ways. We quantified habitat use, morphology, and performance of 19 species of lizards (family Scincidae, subfamily Lygosominae) from 23 populations in tropical Australia. These species use habitats with considerable variation in rock availability. Comparative phylogenetic analyses revealed that occupation of rock-dominated habitats correlated with the evolution of increased limb length, compared to species from forest habitats that predominantly occupied leaf litter. Moreover, increased limb length directly affected performance, with species from rocky habitats having greater sprinting, climbing, and clinging ability than their relatives from less rocky habitats. Thus, we found that the degree of rock use is correlated with both morphological and performance evolution in this group of tropical lizards.

  1. Defense behavior and tail loss in the endemic lizard Eurolophosaurus nanuzae (Squamata, Tropiduridae from southeastern Brazil

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    Conrado A. B. Galdino

    2006-09-01

    Full Text Available Defense behavior of the endemic tropidurid lizard Eurolophosaurus nanuzae was studied in an area of rocky outcrops at Serra do Cipó, Minas Gerais State, southeastern Brazil. Tail loss aspects of this species were also studied in lizards from three populations (Diamantina, Serra do Cipó, and Serro, Minas Gerais State, Brazil. Lizards relied primarily on crypsis to avoid detection by predators. Secondary defense strategies involved a complex set of behaviors. Mean maximum distance of flight was 1.68 ± 1.70 m. When captured,individuals attempted to flee, lifted the tail, produced distress calls, discharged the cloacal contents, waived their tails, and bit. Frequency of tail autotomy was 13.2% (n = 53 in Diamantina, 11.9% (n = 42 in Serra do Cipó, and 4.1% (n = 49 in Serro. Tail autotomy frequency did not differ among the three populations (X2 = 3.3, DF =2, p = 0.19. Tail autotomy did not vary between the years of the study (X2 = 1.32, p = 0.35 and did not differ between males and females among the studied populations.

  2. Tracing the developmental origin of a lizard skull: Chondrocranial architecture, heterochrony, and variation in lacertids.

    Science.gov (United States)

    Yaryhin, Oleksandr; Werneburg, Ingmar

    2018-06-08

    The sand lizard, Lacerta agilis, is a classical model species in herpetology. Its adult skull anatomy and its embryonic development are well known. The description of its fully formed primordial skull by Ernst Gaupp, in 1900, was a key publication in vertebrate morphology and influenced many comparative embryologists. Based on recent methodological considerations, we restudied the early cranial development of this species starting as early as the formation of mesenchymal condensations up to the fully formed chondrocranium. We traced the formation of the complex chondrocranial architecture in detail, clarified specific homologies for the first time, and uncovered major differences to old textbook descriptions. Comparison with other lacertid lizards revealed a very similar genesis of the primordial skull. However, we detected shifts in the developmental timing of particular cartilaginous elements, mainly in the nasal region, which may correlate to specific ecological adaptation in the adults. Late timing of nasal elements might be an important innovation for the successful wide range distribution of the well-known sand lizard. © 2018 Wiley Periodicals, Inc.

  3. Aridification driven diversification of fan-throated lizards from the Indian subcontinent.

    Science.gov (United States)

    Deepak, V; Karanth, Praveen

    2018-03-01

    The establishment of monsoon climate and the consequent aridification has been one of the most important climate change episodes in the Indian subcontinent. However, little is known about how these events might have shaped the diversification patterns among the widely distributed taxa. Fan-throated lizards (FTL) (Genus: Sitana, Sarada) are widespread, diurnal and restricted to the semi-arid zones of the Indian subcontinent. We sampled FTL in 107 localities across its range. We used molecular species delimitation method and delineated 15 species including six putative species. Thirteen of them were distinguishable based on morphology but two sister species were indistinguishable and have minor overlaps in distribution. Five fossils were used to calibrate and date the phylogeny. Diversification of fan-throated lizards lineage started ~18 mya and higher lineage diversification was observed after 11 my. The initial diversification corresponds to the time when monsoon climate was established and the latter was a period of intensification of monsoon and initiation of aridification. Thirteen out of the fifteen FTL species delimited are from Peninsular India; this is probably due to the landscape heterogeneity in this region. The species poor sister genus Otocryptis is paraphyletic and probably represents relict lineages which are now confined to forested areas. Thus, the seasonality led changes in habitat, from forests to open habitats appear to have driven diversification of fan-throated lizards. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata)

    Science.gov (United States)

    Mestre, Ana Paula; Amavet, Patricia Susana; Siroski, Pablo Ariel

    2017-01-01

    The genus Salvator is widely distributed throughout South America. In Argentina, the species most abundant widely distributed is Salvator merianae. Particularly in Santa Fe province, the area occupied by populations of these lizards overlaps with areas where agriculture was extended. With the aim of established baseline values for four immunologic biomarkers widely used, 36 tegu lizards were evaluated tacking into account different age classes and both sexes. Total leukocyte counts were not different between age classes. Of the leucocytes count, eosinophils levels were higher in neonates compared with juvenile and adults; nevertheless, the heterophils group was the most prevalent leukocyte in the peripheral blood in all age classes. Lymphocytes, monocytes, heterophils, azurophils and basophils levels did not differ with age. Natural antibodies titres were higher in the adults compared with neonates and juveniles lizards. Lastly, complement system activity was low in neonates compared with juveniles and adults. Statistical analysis within each age group showed that gender was not a factor in the outcomes. Based on the results, we concluded that S. merianae demonstrated age (but not gender) related differences in the immune parameters analyzed. Having established baseline values for these four widely-used immunologic biomarkers, ongoing studies will seek to optimize the use of the S. merianae model in future research. PMID:28652981

  5. Correlation between ovarian steroidogenesis and beta-endorphin in the Lizard Uromastyx acanthinura: Immunohistochemical approach.

    Directory of Open Access Journals (Sweden)

    Jean Marie Exbrayat

    2010-01-01

    Full Text Available In Mammals, opioid peptides are involved in various physiological processes including the reproductive function. The knowledge of the distribution of beta-endorphin, one of opioid peptides in Reptiles ovaries is very limited. Therefore, the present study used the lizard ovarian follicles to further elucidate the role of this peptide in steroidogenesis. In Uromastyx acanthinura, the localization of both this peptide and sex steroid hormone was investigated by the immunohistochemical approach. This technique was used to evaluate the distribution of these substances and their relationship. The beta-endorphin is strongly distributed in the granulosa cells and oocyte cytoplasm of the previtellogenic follicles in sexually quiescent lizards (winter when steroidogenesis was interrupted. In spring, the signal became weak, or even absent, in the vitellogenic and previtellogenic follicles. The granulosa cells of the previtellogenic follicles showed an important synthesis of 17beta-estradiol. Females that did not undergo in vitellogenesis in spring showed the same profile than quiescent females of winter. These findings represent the first evidence of the presence of beta-endorphin in the ovary of this lizard. The seasonal variations observed in the reproductive cycle suggest that this opioid peptide is involved in the modulation of seasonal steroidogenesis.

  6. New insights into sex chromosome evolution in anole lizards (Reptilia, Dactyloidae).

    Science.gov (United States)

    Giovannotti, M; Trifonov, V A; Paoletti, A; Kichigin, I G; O'Brien, P C M; Kasai, F; Giovagnoli, G; Ng, B L; Ruggeri, P; Cerioni, P Nisi; Splendiani, A; Pereira, J C; Olmo, E; Rens, W; Caputo Barucchi, V; Ferguson-Smith, M A

    2017-03-01

    Anoles are a clade of iguanian lizards that underwent an extensive radiation between 125 and 65 million years ago. Their karyotypes show wide variation in diploid number spanning from 26 (Anolis evermanni) to 44 (A. insolitus). This chromosomal variation involves their sex chromosomes, ranging from simple systems (XX/XY), with heterochromosomes represented by either micro- or macrochromosomes, to multiple systems (X 1 X 1 X 2 X 2 /X 1 X 2 Y). Here, for the first time, the homology relationships of sex chromosomes have been investigated in nine anole lizards at the whole chromosome level. Cross-species chromosome painting using sex chromosome paints from A. carolinensis, Ctenonotus pogus and Norops sagrei and gene mapping of X-linked genes demonstrated that the anole ancestral sex chromosome system constituted by microchromosomes is retained in all the species with the ancestral karyotype (2n = 36, 12 macro- and 24 microchromosomes). On the contrary, species with a derived karyotype, namely those belonging to genera Ctenonotus and Norops, show a series of rearrangements (fusions/fissions) involving autosomes/microchromosomes that led to the formation of their current sex chromosome systems. These results demonstrate that different autosomes were involved in translocations with sex chromosomes in closely related lineages of anole lizards and that several sequential microautosome/sex chromosome fusions lead to a remarkable increase in size of Norops sagrei sex chromosomes.

  7. Light reflection from crystal platelets in iridophores determines green or brown skin coloration in Takydromus lizards.

    Science.gov (United States)

    Kuriyama, Takeo; Esashi, Jyunko; Hasegawa, Masami

    2017-04-01

    Brown and green are the most commonly imitated colors in prey animals because both colors occur in a range of habitats. Many researchers have evaluated survival with respect to background color matching, but the pigment cell mechanisms underlying such coloration are not known. Dorsal coloration of East Asian Takydromus lizards has shifted from green to brown or from brown to green on multiple occasions during the diversification of the genus, thus giving us an opportunity to examine the cellular mechanisms of background color matching. Brown and green skin were found to differ with respect to the morphological characteristics of iridophores, with different thicknesses of the reflecting platelets and the cytoplasmic spacing between platelets, despite a shared vertical arrangement of pigment cells, i.e., xanthophores in the upper layer, iridophores in the middle layer, and melanophores at the bottom of the dermal layer, among the different Takydromus lizards. Iridophores of brown skin reflected longer wavelengths of light than those of green skin, which may be attributed to the thicker platelets and longer distances between platelets in brown skin. We discuss the potential role of genetic and intracellular mechanisms explaining the thickness and orientation of the light-reflecting platelets of iridophores in Takydromus lizards. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. IV. Alopoglossidae, Gymnophthalmidae.

    Science.gov (United States)

    Ribeiro-Júnior, Marco A; Amaral, Silvana

    2017-05-22

    We present distribution data of all Alopoglossidae and Gymnophthalmidae lizards known from the Brazilian Amazonia, totaling 54 species-level taxa, belonging to 17 genera and two families. This represents 22 more species-level taxa than previously reported. Data were based on 17,431 specimens deposited in three North American and eight Brazilian museums, including the main collections harboring Amazonian material. Most species (~80%) are endemic to Amazonia; non-endemic species are mainly associated with open vegetation (savanna) enclaves or open dry (semideciduous) forest in Amazonia, with a few exceptions. As a whole, seven taxa (including one species complex) are widespread in Amazonia, six are restricted to eastern Amazonia, seven to western Amazonia, two to southwestern Amazonia, 11 to southern Amazonia, 11 to northern Amazonia (either in part of it or widespread in the Guiana region), and six to the southern peripheral portion of Amazonia. Besides, four species present unique distributions. Considering this study and the other three catalogues of distribution of lizards already published, the total number of lizard species from Brazilian Amazonia increased from 97 to 142 species-level tava. It represents an increase of 45 species from the region since the last revision.

  9. When Field Experiments Yield Unexpected Results: Lessons Learned from Measuring Selection in White Sands Lizards

    Science.gov (United States)

    Hardwick, Kayla M.; Harmon, Luke J.; Hardwick, Scott D.; Rosenblum, Erica Bree

    2015-01-01

    Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

  10. Mimicking lizard-like surface structures upon ultrashort laser pulse irradiation of inorganic materials

    Science.gov (United States)

    Hermens, U.; Kirner, S. V.; Emonts, C.; Comanns, P.; Skoulas, E.; Mimidis, A.; Mescheder, H.; Winands, K.; Krüger, J.; Stratakis, E.; Bonse, J.

    2017-10-01

    Inorganic materials, such as steel, were functionalized by ultrashort laser pulse irradiation (fs- to ps-range) to modify the surface's wetting behavior. The laser processing was performed by scanning the laser beam across the surface of initially polished flat sample material. A systematic experimental study of the laser processing parameters (peak fluence, scan velocity, line overlap) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, grooves, spikes, etc.). Analyses of the surface using optical as well as scanning electron microscopy revealed morphologies providing the optimum similarity to the natural skin of lizards. For mimicking skin structures of moisture-harvesting lizards towards an optimization of the surface wetting behavior, additionally a two-step laser processing strategy was established for realizing hierarchical microstructures. In this approach, micrometer-scaled capillaries (step 1) were superimposed by a laser-generated regular array of small dimples (step 2). Optical focus variation imaging measurements finally disclosed the three dimensional topography of the laser processed surfaces derived from lizard skin structures. The functionality of these surfaces was analyzed in view of wetting properties.

  11. Sexual Dimorphisms of Appendicular Musculoskeletal Morphology Related to Social Display in Cuban Anolis Lizards.

    Science.gov (United States)

    Anzai, Wataru; Cádiz, Antonio; Endo, Hideki

    2015-10-01

    In Anolis lizards, sexual dimorphism has been reported in morphological and ecological traits. Males show larger body size and longer limbs related to territorial combat and courtship display with the dewlap. Although functional-anatomical traits are closely related to locomotor behaviors, differences between sexes in musculoskeletal traits on limbs remain unclear. We explored the relationships among sexual dimorphisms in musculoskeletal morphology, habitat, and locomotor traits in Anolis lizards. Specifically, we examined appendicular musculoskeletal morphology in three species of Cuban Anolis by measuring muscle mass and lengths of moment arms. Through comparisons of crossing locomotion, we found that the runner species possessed larger extensors in hindlimbs, which are advantageous for running, whereas the masses of the humeral and femoral retractors were larger in climber species, allowing these lizards to hold up their bodies and occupy tree substrates. Comparisons between the sexes showed different trends among the three species. Males of A. porcatus, which inhabit narrow branches or leaves, had stronger elbow extensors that maintain the display posture. In contrast, males of A. sagrei, which occupy broad surfaces, did not show sexual differences that affected social display. Moreover, A. bartschi indicated sexual differences despite the absence of dewlapping behavior. Our findings suggest that both sexes show fundamentally similar relationships between muscular morphology and locomotor habits to adapt arboreal or terrestrial substrates, and yet sexual dimorphism in forelimb muscles may additionally affected by male specific display with the dewlap.

  12. Living in sympatry: The effect of habitat partitioning on the thermoregulation of three Mediterranean lizards.

    Science.gov (United States)

    Sagonas, Kostas; Kapsalas, Grigoris; Valakos, Efstratios; Pafilis, Panayiotis

    2017-04-01

    The ability for effective, accurate and precise thermoregulation is of paramount importance for ectotherms. Sympatric lizards often partition their niche and select different microhabitats. These microhabitats, however, usually differ in their thermal conditions and lizards have to adapt their thermoregulation behavior accordingly. Here, we evaluated the impact of habitat partitioning on the thermal biology of three syntopic, congeneric lacertids (Podarcis peloponnesiacus, P. tauricus and P. muralis) from central Peloponnese, Greece. We assessed thermoregulation effectiveness (E) using the three standard thermal parameters: body (T b ), operative (T e ) and preferred (T pref ) temperatures. We hypothesized that the microhabitats used by each species would differ in thermal quality. We also predicted that all species would effectively thermoregulate, as they inhabit a thermally challenging mountain habitat. As expected, the partition of the habitat had an effect on the thermoregulation of lizards since microhabitats had different thermal qualities. All three species were effective and accurate thermoregulators but one of them achieved smaller E values as a result of the lower T b in the field. This discrepancy could be attributed to the cooler (but more benign) thermal microhabitats that this species occupies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Wall lizards display conspicuous signals to conspecifics and reduce detection by avian predators

    Science.gov (United States)

    Stevens, Martin

    2014-01-01

    Visual signals are often under conflicting selection to be hidden from predators while being conspicuous to mates and rivals. Here, we investigated whether 3 different island populations of Aegean wall lizards (Podarcis erhardii) with variable coloration among diverse island habitats exhibit simultaneous camouflage and sexual signals. We examined whether signals appear better tuned to conspecific vision as opposed to that of avian predators, and whether background-matching camouflage and sexual signals are partitioned to specific body regions. This could facilitate both covert sexual signaling and camouflage according to the viewing perspectives of predators and conspecifics. We found that lizards typically appeared twice as conspicuous to conspecifics than to avian predators against the same visual background, largely due to lizards’ enhanced sensitivity to ultraviolet, suggesting that P. erhardii signals are tuned to conspecific vision to reduce detection by predators. Males were more conspicuous than females to both predators and conspecifics. In 2 populations, male backs were relatively more camouflaged to predators compared to signaling flanks, whereas in females, exposed and concealed surfaces were camouflaged to predators and generally did not differ in background matching. These findings indicate that lizard coloration evolves under the competing demands of natural and sexual selection to promote signals that are visible to conspecifics while being less perceptible to avian predators. They also elucidate how interactions between natural and sexual selection influence signal detectability and partitioning to different body regions, highlighting the importance of considering receiver vision, viewing perspectives, and signaling environments in studies of signal evolution. PMID:25419083

  14. Low rate of interchromosomal rearrangements during old radiation of gekkotan lizards (Squamata: Gekkota).

    Science.gov (United States)

    Johnson Pokorná, Martina; Trifonov, Vladimir A; Rens, Willem; Ferguson-Smith, Malcolm A; Kratochvíl, Lukáš

    2015-06-01

    Gekkotan lizards are a highly specious (∼1600 described species) clade of squamate lizards with nearly cosmopolitan distribution in warmer areas. The clade is primarily nocturnal and forms an ecologically dominant part of the world nocturnal herpetofauna. However, molecular cytogenetic methods to study the evolution of karyotypes have not been widely applied in geckos. Our aim here was to uncover the extent of chromosomal rearrangements across the whole group Gekkota and to search for putative synapomorphies supporting the newly proposed phylogenetic relationships within this clade. We applied cross-species chromosome painting with the recently derived whole-chromosomal probes from the gekkonid species Gekko japonicus to members of the major gekkotan lineages. We included members of the families Diplodactylidae, Carphodactylidae, Pygopodidae, Eublepharidae, Phyllodactylidae and Gekkonidae. Our study demonstrates relatively high chromosome conservatism across the ancient group of gekkotan lizards. We documented that many changes in chromosomal shape across geckos can be attributed to intrachromosomal rearrangements. The documented rearrangements are not totally in agreement with the recently newly erected family Phyllodactylidae. The results also pointed to homoplasy, particularly in the reuse of chromosome breakpoints, in the evolution of gecko karyotypes.

  15. A gravid lizard from the Cretaceous of China and the early history of squamate viviparity

    Science.gov (United States)

    Wang, Yuan; Evans, Susan E.

    2011-09-01

    Although viviparity is most often associated with mammals, roughly one fifth of extant squamate reptiles give birth to live young. Phylogenetic analyses indicate that the trait evolved more than 100 times within Squamata, a frequency greater than that of all other vertebrate clades combined. However, there is debate as to the antiquity of the trait and, until now, the only direct fossil evidence of squamate viviparity was in Late Cretaceous mosasauroids, specialised marine lizards without modern equivalents. Here, we document viviparity in a specimen of a more generalised lizard, Yabeinosaurus, from the Early Cretaceous of China. The gravid female contains more than 15 young at a level of skeletal development corresponding to that of late embryos of living viviparous lizards. This specimen documents the first occurrence of viviparity in a fossil reptile that was largely terrestrial in life, and extends the temporal distribution of the trait in squamates by at least 30 Ma. As Yabeinosaurus occupies a relatively basal position within crown-group squamates, it suggests that the anatomical and physiological preconditions for viviparity arose early within Squamata.

  16. Energetic costs of performance in trained and untrained Anolis carolinensis lizards.

    Science.gov (United States)

    Lailvaux, Simon P; Wang, Andrew Z; Husak, Jerry F

    2018-03-12

    The energetic costs of performance constitute a non-trivial component of animals' daily energetic budgets. However, we currently lack an understanding of how those costs are partitioned among the various stages of performance development, maintenance, and production. We manipulated individual investment in performance by training Anolis carolinensis lizards for endurance or sprinting ability. We then measured energetic expenditure both at rest and immediately following exercise to test whether such training alters the maintenance and production costs of performance. Trained lizards had lower resting metabolic rates than controls, suggestive of a maintenance saving associated with enhanced performance as opposed to a cost. Production costs also differed, with sprint-trained lizards incurring the largest energetic performance cost and experiencing the longest recovery times compared to endurance trained and control animals. Although performance training modifies metabolism, production costs are probably the key drivers of trade-offs between performance and other life-history traits in this species. © 2018. Published by The Company of Biologists Ltd.

  17. Pre- and Postcopulatory Traits of Salvator Male Lizards in Allopatry and Sympatry

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    Sergio Naretto

    2016-01-01

    Full Text Available The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sympatry. Lizards may vary their reproductive strategies through varying sexual characters, body size, gonadal investment, and sperm traits. We evaluated the reproductive traits, involved in pre- and postcopulatory competition, in allopatric and sympatric populations of Salvator lizards. We observed a spatial gradient of male competition among populations, with the following order: allopatric zone of S. rufescens; sympatric zone; and allopatric zone of S. merianae. Accordingly, variation in secondary sexual character, the relative testis mass, and the length of sperm component was observed between allopatry and sympatry in each species, suggesting differences in the investment of reproductive traits. However, we found that these two Salvator species did not differ in secondary sexual characters in sympatry. Interestingly, the trade-off between testes and muscle varied differently from allopatry to sympatry between these Salvator species, suggesting that the influence of social context on reproductive traits investment would affect lizard species differently.

  18. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata).

    Science.gov (United States)

    Mestre, Ana Paula; Amavet, Patricia Susana; Siroski, Pablo Ariel

    2017-01-01

    The genus Salvator is widely distributed throughout South America. In Argentina, the species most abundant widely distributed is Salvator merianae . Particularly in Santa Fe province, the area occupied by populations of these lizards overlaps with areas where agriculture was extended. With the aim of established baseline values for four immunologic biomarkers widely used, 36 tegu lizards were evaluated tacking into account different age classes and both sexes. Total leukocyte counts were not different between age classes. Of the leucocytes count, eosinophils levels were higher in neonates compared with juvenile and adults; nevertheless, the heterophils group was the most prevalent leukocyte in the peripheral blood in all age classes. Lymphocytes, monocytes, heterophils, azurophils and basophils levels did not differ with age. Natural antibodies titres were higher in the adults compared with neonates and juveniles lizards. Lastly, complement system activity was low in neonates compared with juveniles and adults. Statistical analysis within each age group showed that gender was not a factor in the outcomes. Based on the results, we concluded that S. merianae demonstrated age (but not gender) related differences in the immune parameters analyzed. Having established baseline values for these four widely-used immunologic biomarkers, ongoing studies will seek to optimize the use of the S. merianae model in future research.

  19. Spontaneous genetic damage in the tegu lizard (Tupinambis merianae): the effect of age.

    Science.gov (United States)

    Schaumburg, Laura G; Poletta, Gisela L; Siroski, Pablo A; Mudry, Marta D

    2014-05-15

    Several studies indicate that certain factors such as age, sex or nutritional status among others, may affect the level of DNA damage, both induced and spontaneous, so it is very important to consider them for a more accurate interpretation of the findings. The aim of this study was to analyze the influence of age, sex, and nest of origin on spontaneous genetic damage of Tupinambis merianae determined by the comet assay (CA) and the micronucleus (MN) test, in order to improve reference data for future in vivo studies of xenobiotics exposure in this species. Sixty-five tegu lizards of three different ages: newborns (NB), juveniles (JUV) and adults (AD), both sexes and from different nests of origin were used. Blood samples were collected from the caudal vein of all animals and the MN test and CA were applied on peripheral blood erythrocytes to determine basal frequency of MN (BFMN) and basal damage index (BDI). The comparison between age groups showed statistically significant differences in the BFMN and BDI (p0.05). A weak negative relationship was found only between BFMN and weight of NB tegu lizard (p=0.014; R(2)=0.245). Basal values of genetic damage obtained with both biomarkers in the tegu lizard evidenced that age is an intrinsic factor that should be taken into account to avoid misunderstanding of the results in future biomonitoring studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata

    Directory of Open Access Journals (Sweden)

    Ana Paula Mestre

    2017-05-01

    Full Text Available The genus Salvator is widely distributed throughout South America. In Argentina, the species most abundant widely distributed is Salvator merianae. Particularly in Santa Fe province, the area occupied by populations of these lizards overlaps with areas where agriculture was extended. With the aim of established baseline values for four immunologic biomarkers widely used, 36 tegu lizards were evaluated tacking into account different age classes and both sexes. Total leukocyte counts were not different between age classes. Of the leucocytes count, eosinophils levels were higher in neonates compared with juvenile and adults; nevertheless, the heterophils group was the most prevalent leukocyte in the peripheral blood in all age classes. Lymphocytes, monocytes, heterophils, azurophils and basophils levels did not differ with age. Natural antibodies titres were higher in the adults compared with neonates and juveniles lizards. Lastly, complement system activity was low in neonates compared with juveniles and adults. Statistical analysis within each age group showed that gender was not a factor in the outcomes. Based on the results, we concluded that S. merianae demonstrated age (but not gender related differences in the immune parameters analyzed. Having established baseline values for these four widely-used immunologic biomarkers, ongoing studies will seek to optimize the use of the S. merianae model in future research.

  1. Natural history of the lizard Enyalius iheringii (Squamata, Leiosauridae in southern Brazilian Atlantic forest

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    Ricardo Rautenberg

    2010-12-01

    Full Text Available Studies on the natural history of the lizard Enyalius iheringii Boulenger, 1885, as well as other tropical lizards, are rare. In this study, some aspects of the natural history of this endemic species from the Atlantic forest are reported in areas of Vale do Itajaí, state of Santa Catarina, Brazil. Twenty individuals were found, of which 18 were collected. Most of them were found over the vegetation (n=17 and on the ground (n=3. The main defensive strategy displayed was camouflage (n=16. Jumping (n=1, jumping and running (n=1 and running (n=2 were also observed in some individuals. When handled, lizards exhibited mouth wide open, hissing, and occasionally biting, as well as color change in males. Regarding its diet, the numerically most important prey was beetles (Coleoptera, followed by Lepidoptera larvae. Beetles, lepidopteran larvae and spiders were the most frequent food items. Males and females did not differ in size. Three sexually mature females (100-113 mm SVL were found in December and January.

  2. Prey availability affects territory size, but not territorial display behavior, in green anole lizards

    Science.gov (United States)

    Stehle, Chelsea M.; Battles, Andrew C.; Sparks, Michelle N.; Johnson, Michele A.

    2017-10-01

    The availability of food resources can affect the size and shape of territories, as well as the behaviors used to defend territories, in a variety of animal taxa. However, individuals within a population may respond differently to variation in food availability if the benefits of territoriality vary among those individuals. For example, benefits to territoriality may differ for animals of differing sizes, because larger individuals may require greater territory size to acquire required resources, or territorial behavior may differ between the sexes if males and females defend different resources in their territories. In this study, we tested whether arthropod abundance and biomass were associated with natural variation in territory size and defense in insectivorous green anole lizards, Anolis carolinensis. Our results showed that both male and female lizards had smaller territories in a habitat with greater prey biomass than lizards in habitats with less available prey, but the rates of aggressive behaviors used to defend territories did not differ among these habitats. Further, we did not find a relationship between body size and territory size, and the sexes did not differ in their relationships between food availability and territory size or behavioral defense. Together, these results suggest that differences in food availability influenced male and female territorial strategies similarly, and that territory size may be more strongly associated with variation in food resources than social display behavior. Thus, anole investment in the behavioral defense of a territory may not vary with territory quality.

  3. The anatomy and histology of caudal autotomy and regeneration in lizards.

    Science.gov (United States)

    Gilbert, Emily A B; Payne, Samantha L; Vickaryous, Matthew K

    2013-01-01

    Abstract Caudal autotomy-the ability to self-detach the tail-is a dramatic adaptation common to many structural-grade lizards. For most species, tail loss is followed by the equally dramatic phenomenon of tail regeneration. Here we review the anatomy and histology of caudal autotomy and regeneration in lizards, drawing heavily from research published over the past 2 decades. The autotomous tail is characterized by various structural adaptations, which act to minimize blood loss and trauma to adjacent tissues. The early phase of wound healing involves a leukocytic response but limited inflammation. Reepithelialization via a specialized wound epithelium is not only critical for scar-free healing but also necessary for subsequent tissue patterning and regenerative outgrowth. Regeneration begins with the formation of the blastema, a mass of proliferating mesenchymal-like cells. As the blastema expands, it is invaded by blood vessels and the spinal cord. Whereas the replacement tail outwardly resembles the original appendage, it differs in several notable respects, including the tissue composition and organization of the skeleton, muscular system, and spinal cord. Increasingly, the lizard tail is being recognized among biomedical scientists as an important model for the study of wound healing and multitissue restoration.

  4. Intersexual chemo-sensation in a “visually-oriented” lizard, Anolis sagrei

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    Simon Baeckens

    2016-03-01

    Full Text Available While the conspicuous visual displays of anoles have been studied in great depth, the possibility that these lizards may also interact through chemical signalling has received hardly any consideration. In this study, we observed the behaviour of male brown anoles (Anolis sagrei when introduced into an environment previously inhabited by female conspecifics, and compared it to when they were introduced into an untreated environment. The males in our tests exhibited significantly more elaborate display behaviour (i.e., greater number of dewlap extensions and head-nods and a significantly greater number of tongue extrusions while in the cage formerly occupied by females than when placed in the untreated, control cage. The absolute numbers of tongue extrusions, however, were relatively low in comparison to average tongue-flick rates of ‘true’ chemically-oriented lizards. Our results strongly suggest that the males were capable of detecting chemical cues left behind by the females. These observations provide the first evidence of intersexual chemo-sensation in an anole lizard.

  5. Biotransformation and Incorporation into Proteins along a Simulated Terrestrial Food Chain

    Energy Technology Data Exchange (ETDEWEB)

    Unrine, J.M., B.P. Jackson and W.A. Hopkins

    2007-01-01

    Selenium is an essential trace element in vertebrates, but there is a narrow concentration range between dietary requirement and toxicity threshold. Although a great deal is known about the biochemistry of Se from a nutritional perspective, considerably less attention has been focused on the specific biochemistry of Se as an environmental toxicant. Recent advances in hyphenated analytical techniques have provided the capability of quantifying specific chemical forms of Se in biological tissues as well as the distribution of Se among macromolecules. We applied liquid chromatography coupled to inductively coupled plasma mass spectrometry to investigate biotransformations of selenomethionine along a simulated terrestrial food chain consisting of selenomethionine exposed crickets (Acheta domesticus) fed to western fence lizards (Sceloporus occidentalis). Evidence was obtained for selenomethionine biotransformation as well as for sex-specific differences in the metabolism of Se compounds and their subsequent incorporation into proteins in the lizard. The results demonstrate the complexities involved in trophic transfer of Se due to the potential for extensive biotransformation and the species- and even sex-specific nature of these biotransformations.

  6. Celestial orientation with the sun not in view: lizards use a time-compensated sky polarization compass.

    Science.gov (United States)

    Maoret, Francesco; Beltrami, Giulia; Bertolucci, Cristiano; Foà, Augusto

    2014-04-01

    The present investigation was aimed at testing whether the lizard sky polarization compass is time compensated. For this purpose, ruin lizards, Podarcis sicula, were both trained and tested for orientation inside a Morris water maze under clear skies with the sun not in view. During training, lizards showed a striking bimodal orientation along the training axis, demonstrating their capability of determining the symmetry plane of the sky polarization pattern and thus the use of polarization information in orientation. After reaching criteria, lizards were kept 7 days in a 6-h fast clock-shift treatment and then released with the sun not in view. Six-hour clock-shifted lizards showed a bimodal distribution of directional choices, which was oriented perpendicularly to the training axis, as it was expected on the basis of the clock-shift. The results show that the only celestial diurnal compass mechanism that does not need a direct vision of the sun disk (i.e., the sky polarization compass) is a time-compensated compass.

  7. Patterns of infestation by chigger mites in four diurnal lizard species from a restinga habitat (Jurubatiba of Southeastern Brazil

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    M. Cunha-Barros

    Full Text Available We studied the parasitism by larvae of the chigger mite Eutrombicula alfreddugesi on the lizard community of Restinga de Jurubatiba, Rio de Janeiro State, Southeastern Brazil. We investigated the patterns of infestation (prevalence and intensity of chigger mites in four sympatric lizards: Tropidurus torquatus, Mabuya agilis, M. macrorhyncha and Cnemidophorus littoralis. All lizards collected were checked for the presence of mites, which were counted under stereomicroscope. We tested the relationship between intensity of infestation and lizard body size for each species using regression analysis. The prevalences and mean intensities (+ one standard deviation of infestation on each host species were, respectively: 100%; 86.4 + 94.6 in T. torquatus (n = 62; 100%; 20.9 + 9.3 in M. agilis (n = 7; 100%; 11.1 + 13.1 in M. macrorhyncha (n = 12; and 95.2%; 19.1 + 16.8 in C. littoralis (n = 21. Only for C. littoralis did body size significantly affect the intensity of infestation (r = 0.27, p = 0.02. For all lizard species, the body parts where chiggers occurred with the highest intensity were those of skin folds and joint regions.

  8. When the going gets tough: behavioural type-dependent space use in the sleepy lizard changes as the season dries.

    Science.gov (United States)

    Spiegel, Orr; Leu, Stephan T; Sih, Andrew; Godfrey, Stephanie S; Bull, C Michael

    2015-11-22

    Understanding space use remains a major challenge for animal ecology, with implications for species interactions, disease spread, and conservation. Behavioural type (BT) may shape the space use of individuals within animal populations. Bolder or more aggressive individuals tend to be more exploratory and disperse further. Yet, to date we have limited knowledge on how space use other than dispersal depends on BT. To address this question we studied BT-dependent space-use patterns of sleepy lizards (Tiliqua rugosa) in southern Australia. We combined high-resolution global positioning system (GPS) tracking of 72 free-ranging lizards with repeated behavioural assays, and with a survey of the spatial distributions of their food and refuge resources. Bayesian generalized linear mixed models (GLMM) showed that lizards responded to the spatial distribution of resources at the neighbourhood scale and to the intensity of space use by other conspecifics (showing apparent conspecific avoidance). BT (especially aggressiveness) affected space use by lizards and their response to ecological and social factors, in a seasonally dependent manner. Many of these effects and interactions were stronger later in the season when food became scarce and environmental conditions got tougher. For example, refuge and food availability became more important later in the season and unaggressive lizards were more responsive to these predictors. These findings highlight a commonly overlooked source of heterogeneity in animal space use and improve our mechanistic understanding of processes leading to behaviourally driven disease dynamics and social structure. © 2015 The Author(s).

  9. Patterns of infestation by chigger mites in four diurnal lizard species from a Restinga habitat (Jurubatiba) of southeastern Brazil.

    Science.gov (United States)

    Cunha-Barros, M; Van Sluys, M; Vrcibradic, D; Galdino, C A; Hatano, F H; Rocha, C F

    2003-08-01

    We studied the parasitism by larvae of the chigger mite Eutrombicula alfreddugesi on the lizard community of Restinga de Jurubatiba, Rio de Janeiro State, Southeastern Brazil. We investigated the patterns of infestation (prevalence and intensity) of chigger mites in four sympatric lizards: Tropidurus torquatus, Mabuya agilis, M. macrorhyncha and Cnemidophorus littoralis. All lizards collected were checked for the presence of mites, which were counted under stereomicroscope. We tested the relationship between intensity of infestation and lizard body size for each species using regression analysis. The prevalences and mean intensities (+ one standard deviation) of infestation on each host species were, respectively: 100%; 86.4 + 94.6 in T. torquatus (n = 62); 100%; 20.9 + 9.3 in M. agilis (n = 7); 100%; 11.1 + 13.1 in M. macrorhyncha (n = 12); and 95.2%; 19.1 + 16.8 in C. littoralis (n = 21). Only for C. littoralis did body size significantly affect the intensity of infestation (r = 0.27, p = 0.02). For all lizard species, the body parts where chiggers occurred with the highest intensity were those of skin folds and joint regions.

  10. Survey of the reptilian fauna of the Kingdom of Saudi Arabia. V. The lizard fauna of Turaif region

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    Mohammed K. Al-Sadoon

    2016-09-01

    Full Text Available Turaif area located in the Northern border region of Saudi Arabia is one of the most important regions of the Kingdom. This work was proposed to throw light on the diversity of lizard fauna investigated through the collection and subsequent identification of specimens from different localities of Turaif region of Kingdom of Saudi Arabia. Sixteen species of lizards belonging to 5 families (Agamidae, Gekkonidae, Lacertidae, Scincidae and Varanidae were recorded. Lacertidae was the most common family. Three species of lizards namely Acanthodactylus orientalis, Acanthodactylus scutellatus and Acanthodactylus grandis were reported for the first time in the Turaif region of Saudi Arabia. The geographical distribution of the collected species within this province was mapped.

  11. The Ecological Associations of Surface-Dwelling Lizards in Qom Province in the Northwest of Central Plateau of Iran

    Science.gov (United States)

    Ebrahimi, Mehregan; Ahmadzadeh, Faraham; Mostafavi, Hossein; Mehrabian, Aahmad Reza; Abdoli, Asghar; Mahini, Abdolrasoul Salman

    2013-01-01

    We used pitfall trapping to investigate the effects of elevation, plant density and soil structure on species diversity and the impact of these habitat factors on lizard habitat selectivity in the Qom Province in the Central Plateau of Iran. From a total of 12 1-ha plots, we captured 363 individuals of 15 species of lizards (six species of Lacertidae, five species of Agamidae, two species of Gekkonidae, one species of Varanidae and one species of Scincidae). A generalized linear model (GLM) determined that elevation was the most important factor impacting species diversity. The highest species diversity was at the intermediate elevation (1289 m). Abundance of 6 out of 15 species showed strong relationships with some habitat factors. These relationships were demonstrated by habitat selectivity index (Ivlev's index). Our result supports other surveys that showed that elevation plays an important role in determining lizard species diversity. PMID:24349557

  12. Diet and foraging of the endemic lizard Cnemidophorus littoralis (Squamata, Teiidae) in the restinga de Jurubatiba, Macaé, RJ.

    Science.gov (United States)

    Menezes, V A; Amaral, V C; Sluys, M V; Rocha, C F D

    2006-08-01

    We investigated the diet and foraging of the endemic teiid lizard Cnemidophorus littoralis in a restinga habitat in Jurubatiba, Macaé - RJ. The stomach contents were removed, analyzed and identified to the Order level. There was no relationship between C. littoralis morphological variables and number, length or volume of preys. Termites (48.7%) and larvae (35.5%) were the most important prey items which occurred in the examined lizards' stomachs. The diet did not differ between males and females. Cnemidophorus littoralis is an active forager and predominantly consumes relatively sedentary prey or prey that is aggregated in the environment. We also found an intact and undigested hatchling of the crepuscular/nocturnal gekkonid lizard Hemidactylus mabouia in the stomach of an adult male of C. littoralis, which indicates that C. littoralis is a potential source of mortality for individuals of H. mabouia in the restinga de Jurubatiba.

  13. Effects of Diet Restriction and Diet Complexity on Life History Strategies in Side-Blotched Lizards (Uta stansburiana).

    Science.gov (United States)

    Skinner, Heather M; Durso, Andrew M; Neuman-Lee, Lorin A; Durham, Susan L; Mueller, Sarah D; French, Susannah S

    2016-11-01

    Organisms must balance energy invested into self-maintenance, reproduction, and somatic growth over their lifetime. In this study, the effects of diet restriction and diet complexity on side-blotched lizards (Uta stansburiana) were analyzed. Thirty male lizards, housed in the laboratory, were fed either an ad libitum or a restricted diet for 18 days (phase 1). Individuals from both treatments were then assigned to a diet of the same quantity of food that was either simple (only crickets) or complex (crickets, cockroaches, waxworms, and mealworms) for 35 days (phase 2). We evaluated (1) how diet restriction affected life history strategies and (2) how diet complexity affected recovery from diet restriction as measured at the end of phase 2 by body mass, snout-vent length, calculated body condition score, wound healing, tail regrowth, bacterial killing ability, oxidative stress, and plasma testosterone and corticosterone concentrations. Lizards without diet restriction allocated more energy to self-maintenance (i.e., maintaining higher body condition scores, healing wounds more quickly) than lizards with diet restriction. Lizards with diet restriction had higher plasma testosterone concentrations and larger increases in snout-vent lengths than those fed ad libitum, which may reflect allocations toward reproduction and somatic growth. A complex diet resulted in better body condition and faster tail regrowth than a simple diet, suggesting that a complex diet enhanced recovery from diet restriction, although long-term life history choices remained unaltered. Finally, lizards on a complex diet consumed substantially less food while maintaining higher body condition, suggesting that key nutrients may be lacking from a simple diet. © 2017 Wiley Periodicals, Inc.

  14. The impact of male contraception on dominance hierarchy and herd association patterns of African elephants (Loxodonta africana) in a fenced game reserve

    OpenAIRE

    L.S. Doughty; K. Slater; H. Zitzer; Tomos Avent; S. Thompson

    2014-01-01

    Overpopulation of African elephants (Loxodonta africana) in fenced reserves in South Africa is becoming increasingly problematic to wildlife managers. With growing opposition to culling and the high cost of translocation, alternative management strategies focusing on male elephants are being investigated. In this study, hormonal treatment via Gonadotropin Releasing Hormone (GnRH) suppression, and surgical treatment via vasectomy were trialled. Focusing on behavioural responses, we tested the ...

  15. Oxygen reduction activities compared in rotating-disk electrode and proton exchange membrane fuel cells for highly active Fe-N-C catalysts

    International Nuclear Information System (INIS)

    Jaouen, F.; Goellner, V.; Lefèvre, M.; Herranz, J.; Proietti, E.; Dodelet, J.P.

    2013-01-01

    In the past three years, two novel synthesis methods for non-precious metal catalysts resulting in a breakthrough of their activity and performance at the cathode of the proton-exchange membrane fuel cell (PEMFC) have been reported by the group of Prof. Dodelet. While the activity of these novel Fe-based catalysts for the oxygen reduction reaction is very high in PEMFC, our preliminary activity measurements with the rotating disk electrode (RDE) technique on one of them showed an activity being a factor 30–100 lower than the one measured in PEMFC at 80 °C. The present work explains to a large extent this huge difference. Two Fe-N-C catalysts synthesized via our novel approaches and one Fe-N-C catalyst synthesized via our classical approach were investigated in RDE and PEMFC. In both systems, the effect of the ink formulation (Nafion-to-catalyst ratio) was investigated. Optimization of the RDE ink formulation explains a factor between 5 and 10 in the two-decade gap mentioned above. Then, the effect of temperature in the RDE system was investigated. An increase from 20 to 80 °C was found to result in a theoretical maximum twofold increase in activity. However, in practice, decreased O 2 solubility with increased temperature cancels this effect. After taking into account these two parameters, a difference in ORR activity between RDE and PEMFC of ca a factor five still remained for one of the two novel Fe-N-C catalysts investigated here. The lower initial activity measured in RDE for this catalyst is shown to be due to the fast adsorption of anions (HSO 4 − ) from the liquid H 2 SO 4 electrolyte on protonated nitrogen atoms (NH + ) found on its surface. The phenomenon of anion adsorption and associated decreased ORR activity also applies to the other novel Fe-N-C catalyst, but is slower and does not immediately occur in RDE.

  16. The role of vicariance vs. dispersal in shaping genetic patterns in ocellated lizard species in the western Mediterranean

    DEFF Research Database (Denmark)

    Paulo, O. S.; Pinheiro, J.; Miraldo, A.

    2008-01-01

    in the western Mediterranean as exemplified by the distribution of species and subspecies and genetic variation within the ocellated lizard group. To reassess the role of the MSC, partial sequences of three mitochondrial DNA genes (cytochrome b, 12S and 16S ribosomal RNA) and two nuclear genes (beta......-fibrinogen and C-mos) from species of the ocellated lizard group were analysed. Three alternative hypotheses were tested: that divergence was initiated (i) by post-MSC vicariance as the basin filled, (ii) when separate populations established either side of the strait by pre-MSC overseas dispersal, and (iii...

  17. Density of the tegu lizard (Tupinambis merianae) and its role as nest predator at Anchieta Island, Brazil

    OpenAIRE

    Bovendorp, Ricardo S.; Alvarez, Ariane D.; Gialetti, Mauro

    2008-01-01

    Mammals has been pointed out to be the main nest predators in islands, but recent studies has shown that tree snakes are also important nest predator in tropical forests. Here we present information on the density tegu lizards Tupinambis merianae and its role as nest predator at Anchieta Island, Ubatuba, in southeastern Brazil. The mean density of tegu lizards wets estimated to be 83 individuals/km2, which is 1.83 times lower than other well-known population (Fernando de Noronha Archipelago)....

  18. The ultrastructure of the spermatozoon of the lizard Iguana iguana (Reptilia, Squamata, Iguanidae) and the variability of sperm morphology among iguanian lizards

    Science.gov (United States)

    Vieira, Gustavo H C; Colli, Guarino R; Báo, Sônia N

    2004-01-01

    The spermatozoon of Iguana iguana is filiform and resembles that of other iguanian lizards, being most similar to Tropidurus. All sperm synapomorphies of Tetrapoda, Amniota and Squamata are present in the sperm of Iguana iguana. By reconstructing the evolution of 30 sperm characters we identified a novel synapomorphy of Iguania: the presence of a well-developed acrosomal ridge at the level of the epinuclear lucent zone. Because of the poor topological resolution among iguanian clades we could not discount the possibility of convergence or neutral selection as determinant of the variability in characteristics of the sperm cell. In agreement with previous studies, we identified heterogeneous rates of evolution among the three main regions of the sperm cell, namely the head, midpiece and tail. PMID:15198687

  19. Evaluation of toxic metals in the industrial effluents and their segregation through peanut husk fence for pollution abatement

    International Nuclear Information System (INIS)

    Husaini, S.N.; Zaidi, J.H.; Matiullah; Akram, M.

    2011-01-01

    The industrial pollution is exponentially growing in the developing countries due to the discharge of untreated effluents from the industries in the open atmosphere. This may cause severe health hazards in the general public. To reduce this effect, it is essential to remove the toxic and heavy metals from the effluents before their disposal into the biosphere. In this context, samples of the effluents were collected from the textile/yarn, ceramics and pulp/paper industries and the concentrations of the toxic metal ions were determined using neutron activation analysis (NAA) technique. The observed concentration values of the As, Cr and Fe ions, in the unprocessed industrial effluents, were 4.91 ± 0.8, 9.67 ± 0.7 and 9.71 ± 0.8 mg/L, respectively which was well above the standard recommended limits (i.e. 1.0, 1.0 and 2.0 mg/L, respectively). In order to remove the toxic metal ions from the effluents, the samples were treated with pea nut husk fence. After this treatment, 91.5% arsenic, 81.9% chromium and 66.5% iron metal ions were successfully removed from the effluents. Then the treated effluents contained concerned toxic metal ions concentrations within the permissible limits as recommended by the national environmental quality standards (NEQS). (author)

  20. Durability of template-free Fe-N-C foams for electrochemical oxygen reduction in alkaline solution

    Science.gov (United States)

    Mufundirwa, Albert; Harrington, George F.; Smid, Břetislav; Cunning, Benjamin V.; Sasaki, Kazunari; Lyth, Stephen M.

    2018-01-01

    Due to the high cost and limited availability of platinum, the development of non-platinum-group metals (non-PGM) catalysts is of paramount importance. A promising alternative to Pt are Fe-N-C-based materials. Here we present the synthesis, characterization and electrochemistry of a template-free nitrogen-doped carbon foam, impregnated with iron. This low-cost and gram-scale method results in materials with micron-scale pore size and large surface area (1600 m2g-1). When applied as an oxygen reduction reaction (ORR) electrocatalyst in alkaline solution, the Fe-N-C foams display extremely high initial activity, slightly out-performing commercially available non-PGM catalysts (NCP-2000, Pajarito Powder). The load-cycle durability in alkaline solution is investigated, and the performance steadily degrades over 60,000 potential cycles, whilst the commercial catalyst is remarkably stable. The post-operation catalyst microstructure is elucidated by transmission electron microscopy (TEM), to provide insight into the degradation processes. The resulting images suggest that potential cycling leads to leaching of atomically dispersed Fe-N2/4 sites in all the catalysts, whereas encapsulated iron nanoparticles are protected.

  1. REMINDER: Compliance with Operational Circular No. 2 (Rev. 1) on “Conditions of access to the fenced CERN site”

    CERN Multimedia

    2012-01-01

    The purpose of Operational Circular No. 2 (Rev. 1) is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. The behaviours that cannot be tolerated under any circumstances are: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the restaurants; dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2 (Rev. 1), namely to refuse access to the site to people and/or their vehicles deemed to be in infringement of the circu...

  2. AN/FSY-3 Space Fence System – Sensor Site One/Operations Center Integration Status and Sensor Site Two Planned Capability

    Science.gov (United States)

    Fonder, G. P.; Hack, P. J.; Hughes, M. R.

    This paper covers two topics related to Space Fence System development: Sensor Site One / Operations Center construction and integration status including risk reduction integration and test efforts at the Moorestown, NJ Integrated Test Bed (ITB); and the planned capability of Sensor Site Two. The AN/FSY-3 Space Fence System is a ground-based system of S-band radars integrated with an Operations Center designed to greatly enhance the Air Force Space Surveillance network. The radar architecture is based on Digital Beam-forming. This capability permits tremendous user-defined flexibility to customize volume surveillance and track sectors instantaneously without impacting routine surveillance functions. Space Fence provides unprecedented sensitivity, coverage and tracking accuracy, and contributes to key mission threads with the ability to detect, track and catalog small objects in LEO, MEO and GEO. The system is net-centric and will seamlessly integrate into the existing Space Surveillance Network, providing services to external users—such as JSpOC—and coordinating handoffs to other SSN sites. Sensor Site One construction on the Kwajalein Atoll is in progress and nearing completion. The Operations Center in Huntsville, Alabama has been configured and will be integrated with Sensor Site One in the coming months. System hardware, firmware, and software is undergoing integration testing at the Mooretown, NJ ITB and will be deployed at Sensor Site One and the Operations Center. The preliminary design for Sensor Site Two is complete and will provide critical coverage, timeliness, and operational flexibility to the overall system.

  3. Re-introduction of globally threatened Arabian Gazelles Gazella Arabica (Pallas, 1766 (Mammalia: Bovidae in fenced protected area in central Saudi Arabia

    Directory of Open Access Journals (Sweden)

    M.Z. Islam

    2014-07-01

    Full Text Available The Arabian Gazelle is a globally threatened antelope (Vulnerable in Saudi Arabia. Small relict populations remain in limited areas, while historically Arabian Gazelles occurred in Mahazat as-Sayd protected area in central Saudi Arabia but were exterminated by anthropogenic and other pressures, including habitat loss and hunting. Important habitat has been lost to agricultural developments, fencing of pasture for livestock and the construction of human settlements and roads. The reintroduction of Arabian Gazelles was undertaken in Mahazat during 2011-2014 to bring back this locally extinct species study its ecology and biology in a fenced protected area. We released a total of 49 (12 males, 37 females animals. A year after release animals started breeding and six calves have been recorded so far with more to come. The gazelles prefer to use more rocky areas where shrubs and acacia trees occur in the reserve, and do not move long distances except for one individual that moved more than 50km. Mahazat is fenced, which prevents local people from entering the reserve to poach or otherwise disturb animals. Management lessons include the need for continued monitor-ing of reintroduced populations. Interactions between Arabian and Sand Gazelles (Gazella subgutturosa marica and Arabian Oryx (Oryx leucoryx were also studied.

  4. Segregating variation for temperature-dependent sex determination in a lizard.

    Science.gov (United States)

    Rhen, T; Schroeder, A; Sakata, J T; Huang, V; Crews, D

    2011-04-01

    Temperature-dependent sex determination (TSD) was first reported in 1966 in an African lizard. It has since been shown that TSD occurs in some fish, several lizards, tuataras, numerous turtles and all crocodilians. Extreme temperatures can also cause sex reversal in several amphibians and lizards with genotypic sex determination. Research in TSD species indicates that estrogen signaling is important for ovary development and that orthologs of mammalian genes have a function in gonad differentiation. Nevertheless, the mechanism that actually transduces temperature into a biological signal for ovary versus testis development is not known in any species. Classical genetics could be used to identify the loci underlying TSD, but only if there is segregating variation for TSD. Here, we use the 'animal model' to analyze inheritance of sexual phenotype in a 13-generation pedigree of captive leopard geckos, Eublepharis macularius, a TSD reptile. We directly show genetic variance and genotype-by-temperature interactions for sex determination. Additive genetic variation was significant at a temperature that produces a female-biased sex ratio (30°C), but not at a temperature that produces a male-biased sex ratio (32.5°C). Conversely, dominance variance was significant at the male-biased temperature (32.5°C), but not at the female-biased temperature (30°C). Non-genetic maternal effects on sex determination were negligible in comparison with additive genetic variance, dominance variance and the primary effect of temperature. These data show for the first time that there is segregating variation for TSD in a reptile and consequently that a quantitative trait locus analysis would be practicable for identifying the genes underlying TSD.

  5. Sequencing, de novo assembling, and annotating the genome of the endangered Chinese crocodile lizard Shinisaurus crocodilurus.

    Science.gov (United States)

    Gao, Jian; Li, Qiye; Wang, Zongji; Zhou, Yang; Martelli, Paolo; Li, Fang; Xiong, Zijun; Wang, Jian; Yang, Huanming; Zhang, Guojie

    2017-07-01

    The Chinese crocodile lizard, Shinisaurus crocodilurus, is the only living representative of the monotypic family Shinisauridae under the order Squamata. It is an obligate semi-aquatic, viviparous, diurnal species restricted to specific portions of mountainous locations in southwestern China and northeastern Vietnam. However, in the past several decades, this species has undergone a rapid decrease in population size due to illegal poaching and habitat disruption, making this unique reptile species endangered and listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora Appendix II since 1990. A proposal to uplist it to Appendix I was passed at the Convention on International Trade in Endangered Species of Wild Fauna and Flora Seventeenth meeting of the Conference of the Parties in 2016. To promote the conservation of this species, we sequenced the genome of a male Chinese crocodile lizard using a whole-genome shotgun strategy on the Illumina HiSeq 2000 platform. In total, we generated ∼291 Gb of raw sequencing data (×149 depth) from 13 libraries with insert sizes ranging from 250 bp to 40 kb. After filtering for polymerase chain reaction-duplicated and low-quality reads, ∼137 Gb of clean data (×70 depth) were obtained for genome assembly. We yielded a draft genome assembly with a total length of 2.24 Gb and an N50 scaffold size of 1.47 Mb. The assembled genome was predicted to contain 20 150 protein-coding genes and up to 1114 Mb (49.6%) of repetitive elements. The genomic resource of the Chinese crocodile lizard will contribute to deciphering the biology of this organism and provides an essential tool for conservation efforts. It also provides a valuable resource for future study of squamate evolution. © The Authors 2017. Published by Oxford University Press.

  6. Zebrin II Is Expressed in Sagittal Stripes in the Cerebellum of Dragon Lizards (Ctenophorus sp.).

    Science.gov (United States)

    Wylie, Douglas R; Hoops, Daniel; Aspden, Joel W; Iwaniuk, Andrew N

    2016-01-01

    Aldolase C, also known as zebrin II (ZII), is a glycolytic enzyme that is expressed in cerebellar Purkinje cells of the vertebrate cerebellum. In both mammals and birds, ZII is expressed heterogeneously, such that there are sagittal stripes of Purkinje cells with high ZII expression (ZII+) alternating with stripes of Purkinje cells with little or no expression (ZII-). In contrast, in snakes and turtles, ZII is not expressed heterogeneously; rather all Purkinje cells are ZII+. Here, we examined the expression of ZII in the cerebellum of lizards to elucidate the evolutionary origins of ZII stripes in Sauropsida. We focused on the central netted dragon (Ctenophorus nuchalis) but also examined cerebellar ZII expression in 5 other dragon species (Ctenophorus spp.). In contrast to what has been observed in snakes and turtles, we found that in these lizards, ZII is heterogeneously expressed. In the posterior part of the cerebellum, on each side of the midline, there were 3 sagittal stripes consisting of Purkinje cells with high ZII expression (ZII+) alternating with 2 sagittal stripes with weaker ZII expression (ZIIw). More anteriorly, most of the Purkinje cells were ZII+, except laterally, where the Purkinje cells did not express ZII (ZII-). Finally, all Purkinje cells in the auricle (flocculus) were ZII-. Overall, the parasagittal heterogeneous expression of ZII in the cerebellum of lizards is similar to that in mammals and birds, and contrasts with the homogenous ZII+ expression seen in snakes and turtles. We suggest that a sagittal heterogeneous expression of ZII represents the ancestral condition in stem reptiles which was lost in snakes and turtles. © 2017 S. Karger AG, Basel.

  7. Phylogenomic analysis of the Chilean clade of Liolaemus lizards (Squamata: Liolaemidae based on sequence capture data

    Directory of Open Access Journals (Sweden)

    Alejandra Panzera

    2017-10-01

    Full Text Available The genus Liolaemus is one of the most ecologically diverse and species-rich genera of lizards worldwide. It currently includes more than 250 recognized species, which have been subject to many ecological and evolutionary studies. Nevertheless, Liolaemus lizards have a complex taxonomic history, mainly due to the incongruence between morphological and genetic data, incomplete taxon sampling, incomplete lineage sorting and hybridization. In addition, as many species have restricted and remote distributions, this has hampered their examination and inclusion in molecular systematic studies. The aims of this study are to infer a robust phylogeny for a subsample of lizards representing the Chilean clade (subgenus Liolaemus sensu stricto, and to test the monophyly of several of the major species groups. We use a phylogenomic approach, targeting 541 ultra-conserved elements (UCEs and 44 protein-coding genes for 16 taxa. We conduct a comparison of phylogenetic analyses using maximum-likelihood and several species tree inference methods. The UCEs provide stronger support for phylogenetic relationships compared to the protein-coding genes; however, the UCEs outnumber the protein-coding genes by 10-fold. On average, the protein-coding genes contain over twice the number of informative sites. Based on our phylogenomic analyses, all the groups sampled are polyphyletic. Liolaemus tenuis tenuis is difficult to place in the phylogeny, because only a few loci (nine were recovered for this species. Topologies or support values did not change dramatically upon exclusion of L. t. tenuis from analyses, suggesting that missing data did not had a significant impact on phylogenetic inference in this data set. The phylogenomic analyses provide strong support for sister group relationships between L. fuscus, L. monticola, L. nigroviridis and L. nitidus, and L. platei and L. velosoi. Despite our limited taxon sampling, we have provided a reliable starting hypothesis for

  8. How to tackle chemical communication? Relative proportions versus semiquantitative determination of compounds in lizard chemical secretions.

    Science.gov (United States)

    García-Roa, Roberto; Sáiz, Jorge; Gómara, Belén; López, Pilar; Martín, José

    2018-02-01

    Knowledge about chemical communication in some vertebrates is still relatively limited. Squamates are a glaring example of this, even when recent evidences indicate that scents are involved in social and sexual interactions. In lizards, where our understanding of chemical communication has considerably progressed in the last few years, many questions about chemical interactions remain unanswered. A potential reason for this is the inherent complexity and technical limitations that some methodologies embody when analyzing the compounds used to convey information. We provide here a straightforward procedure to analyze lizard chemical secretions based on gas chromatography coupled to mass spectrometry that uses an internal standard for the semiquantification of compounds. We compare the results of this method with those obtained by the traditional procedure of calculating relative proportions of compounds. For such purpose, we designed two experiments to investigate if these procedures allowed revealing changes in chemical secretions 1) when lizards received previously a vitamin dietary supplementation or 2) when the chemical secretions were exposed to high temperatures. Our results show that the procedure based on relative proportions is useful to describe the overall chemical profile, or changes in it, at population or species levels. On the other hand, the use of the procedure based on semiquantitative determination can be applied when the target of study is the variation in one or more particular compounds of the sample, as it has proved more accurate detecting quantitative variations in the secretions. This method would reveal new aspects produced by, for example, the effects of different physiological and climatic factors that the traditional method does not show.

  9. Evidence for a carotid body homolog in the lizard Tupinambis merianae.

    Science.gov (United States)

    Reichert, Michelle N; Brink, Deidre L; Milsom, William K

    2015-01-15

    The homolog to the mammalian carotid body has not yet been identified in lizards. Observational studies and evolutionary history provide indirect evidence for the existence of a chemoreceptor population at the first major bifurcation of the common carotid artery in lizards, but a chemoreceptive role for this area has not yet been definitively demonstrated. We explored this possibility by measuring changes in cardiorespiratory variables in response to focal arterial injections of the hypoxia mimic sodium cyanide (NaCN) into the carotid artery of 12 unanesthetized specimens of Tupinambis merianae. These injections elicited increases in heart rate (f(H); 101±35% increase) and respiratory rate (f(R); 620±119% increase), but not mean arterial blood pressure (MAP). These responses were eliminated by vagal denervation. Similar responses were elicited by injections of the neurotransmitters acetylcholine (ACh) and serotonin (5-HT) but not norepinephrine. Heart rate and respiratory rate increases in response to NaCN could be blocked or reduced by antagonists to ACh (atropine) and/or 5-HT (methysergide). Finally, using immunohistochemistry, we demonstrate the presence of putative chemoreceptive cells immunopositive for the cholinergic cell marker vesicular ACh transporter (VAChT) and 5-HT on internal lattice-like structures at the carotid bifurcation. These results provide evidence in lizards for the existence of dispersed chemoreceptor cells at the first carotid bifurcation in the central cardiovascular area that have similar properties to known carotid body homologs, adding to the picture of chemoreceptor evolution in vertebrates. © 2015. Published by The Company of Biologists Ltd.

  10. Genotoxicity induced by Roundup® (Glyphosate) in tegu lizard (Salvator merianae) embryos.

    Science.gov (United States)

    Schaumburg, Laura G; Siroski, Pablo A; Poletta, Gisela L; Mudry, Marta D

    2016-06-01

    Environmental contaminants produce multiple adverse consequences at individual, population and ecosystem levels. High volumes of agrochemicals applied to great variety of crops, together with agricultural expansion, generate great concerns due to the impact for the environment and large risk implicated for wildlife. The lack of data on these threats is striking. The tegu lizard (Salvator merianae) is one of the species that live in environments under contaminant effects. Several characteristics allow proposing this species as a potential sentinel organism for the monitoring of pesticides in their habitat. The present study is the first report about genotoxicity in tegu lizard neonates after embryonic exposure to Roundup® (glyphosate 66.2%). The micronucleus test (MN), nuclear abnormalities (NAs) assay and comet assay (CA) were used as biomarkers of genotoxic effects induced in erythrocytes by topical exposure of the eggs to the glyphosate commercial formulation Roundup® (RU), in laboratory controlled conditions. A total of 96 eggs were distributed in six groups exposed to RU (50, 100, 200, 400, 800, 1600μg/egg), one positive control (PC; 200μg cyclophosphamide/egg) and one negative control (NC; distilled water). No teratogenic effects were observed in any of the exposed or control neonates. A significant increase in DNA damage was observed in all concentrations higher than 100μg/egg with respect to NC (p0.05). Our results provide new information about the undesirable effects of the glyphosate-based herbicide formulations RU on this lizard species that inhabits areas permanently exposed to several pesticide formulations. We consider of utmost necessity a strict regulation of the agrochemical application conditions in those environments near to places where wild populations of terrestrial and aquatic species live, in order to minimize the adverse effects on ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. A decrease in nasal CO2 stimulates breathing in the tegu lizard.

    Science.gov (United States)

    Coates, E L; Furilla, R A; Ballam, G O; Bartlett, D

    1991-10-01

    Tegu lizards decrease ventilatory frequency (f) when constant CO2, as low as 0.4%, is delivered to the nasal cavities. In contrast, CO2, as high as 6%, pulsed into the nasal cavities during the expiratory phase of the breathing cycle does not alter f. The purpose of the present study was to investigate further the effect of nasal CO2 pattern on f in tegu lizards. Specifically, we tested: (1) whether f was affected by CO2 delivered to the nasal cavities during the inspiratory phase of the breathing cycle, and (2) whether pulsed decreases in nasal CO2 from 4% to 2% and from 4% to 0% would remove the f inhibition caused by constant nasal CO2. Ventilation was measured using a pneumotachograph and pressure transducer in-line with an endotracheal T-tube inserted through the glottis. CO2 was delivered to the nasal cavities through small tubes inserted into the external nares. Ventilatory frequency was not significantly altered when 4% CO2 was pulsed into the nasal cavities during inspiration. Dropping the CO2 in the nasal cavities from 4% to 0% at either 15 cycles/min (0.25 Hz) or for one cycle stimulated breathing. There was no significant difference between the f response to a drop in CO2 from 4% to 0% and that to a drop in CO2 from 4% to 2%. The failure to link the phasic CO2 ventilatory response to a phase in the respiratory cycle indicates that the nasal CO2 receptors do not participate in the breath-by-breath regulation of breathing in these lizards. The observation that small decreases in nasal CO2 abolished the f inhibition caused by constant nasal CO2 provides further evidence for the ability of the nasal CO2 receptors to distinguish between pulsed and constant CO2.

  12. The VIP/VPACR system in the reproductive cycle of male lizard Podarcis sicula.

    Science.gov (United States)

    Agnese, Marisa; Rosati, Luigi; Prisco, Marina; Coraggio, Francesca; Valiante, Salvatore; Scudiero, Rosaria; Laforgia, Vincenza; Andreuccetti, Piero

    2014-09-01

    Starting from the knowledge that in the reproductive period the Vasoactive Intestinal Peptide (VIP) is widely distributed in Podarcis sicula testis, we studied VIP expression and the localization of the neuropeptide and its receptors in the testis of the Italian wall lizard P. sicula in the other phases of its reproductive cycle (summer stasis, autumnal resumption, winter stasis, spring resumption). By Real Time-PCR, we demonstrated that testicular VIP mRNA levels change during the reproductive cycle, showing a cyclic trend with two peaks, one in the mid-autumnal resumption and the other in the reproductive period. By in situ hybridization and immunohistochemistry, we demonstrated that both VIP mRNA and protein were widely distributed in the testis in almost all the phases of the cycle, except in the early autumnal resumption. As regards the receptors, the VPAC1R was localized mainly in Leydig cells, while the VPAC2R showed the same distribution of VIP. Our results demonstrate that, differently from mammals, where VIP is present only in nerve fibres innerving the testis, an endotesticular synthesis takes place in the lizard and the VIP synthesis changes throughout the reproductive cycle. Moreover, the VIP/VPAC receptor system distribution observed in germ and somatic cells in various phases of the cycle, and particularly in the autumnal resumption and the reproductive period, strongly suggests its involvement in both spermatogenesis and steroidogenesis. Finally, the wider distribution of VIP in lizards with respect to mammals leads us to hypothesize that during the evolution the synthesis sites have been transferred from the testis to other districts, such as the brain. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Effect of gamma-rays on the life-shortening of the lizard uromastyx hardwickii

    International Nuclear Information System (INIS)

    Ahmed, M.; Taqawi, I.H.

    1978-01-01

    Three groups of starved lizards, Uromastyx hardwickii, in 3 groups were exposed to 60 Co gamma radiation of 3000 R, 3500 R, and 4000 R, resp., maintained at 30 0 +- 1 0 C, and observed for 4 weeks. Increase of irradiation decreased the survival time. The LD 50 /30 days was about 4000 R. This appears to be the highest dose so far obtained for any vertebrate, and indicates poikilotherms to respond differently from homoiotherms. The higher radioresistance of cold-blooded animals appears to be due to the low metabolic activity. (author)

  14. Yolk sac development in lizards (Lacertilia: Scincidae): New perspectives on the egg of amniotes.

    Science.gov (United States)

    Stewart, James R; Thompson, Michael B

    2017-04-01

    Embryos of oviparous reptiles develop on the surface of a large mass of yolk, which they metabolize to become relatively large hatchlings. Access to the yolk is provided by tissues growing outward from the embryo to cover the surface of the yolk. A key feature of yolk sac development is a dedicated blood vascular system to communicate with the embryo. The best known model for yolk sac development and function of oviparous amniotes is based on numerous studies of birds, primarily domestic chickens. In this model, the vascular yolk sac forms the perimeter of the large yolk mass and is lined by a specialized epithelium, which takes up, processes and transports yolk nutrients to the yolk sac blood vessels. Studies of lizard yolk sac development, dating to more than 100 years ago, report characteristics inconsistent with this model. We compared development of the yolk sac from oviposition to near hatching in embryonic series of three species of oviparous scincid lizards to consider congruence with the pattern described for birds. Our findings reinforce results of prior studies indicating that squamate reptiles mobilize and metabolize the large yolk reserves in their eggs through a process unknown in other amniotes. Development of the yolk sac of lizards differs from birds in four primary characteristics, migration of mesoderm, proliferation of endoderm, vascular development and cellular diversity within the yolk sac cavity. Notably, all of the yolk is incorporated into cells relatively early in development and endodermal cells within the yolk sac cavity align along blood vessels which course throughout the yolk sac cavity. The pattern of uptake of yolk by endodermal cells indicates that the mechanism of yolk metabolism differs between lizards and birds and that the evolution of a fundamental characteristic of embryonic nutrition diverged in these two lineages. Attributes of the yolk sac of squamates reveal the existence of phylogenetic diversity among amniote lineages

  15. Lizards and Amphisbaenians, municipality of Viçosa, state of Minas Gerais, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigues, A. C.

    2009-01-01

    Full Text Available We performed a survey of lizards and amphisbaenians from municipality of Viçosa, in Atlantic Forest from state ofMinas Gerais, southeastern Brazil, based on data of the herpetological collections of Museu de Zoologia João Moojen,Universidade Federal de Viçosa, and Museu de Zoologia, Universidade de São Paulo. One hundred and forty sixspecimens of 14 species were analyzed, belonging to the following families: Amphisbaenidae, Anguidae, Gekkonidae,Gymnophthalmidae, Leiosauridae, Polychrotidae, Scincidae, Teiidae and Tropiduridae. We hope to supply basicinformation that helps to understand species distribution of this group in the Atlantic Forest of Minas Gerais andsoutheastern Brazil.

  16. Resurrection of Bronchocela burmana Blanford, 1878 for the Green Crested Lizard (Squamata, Agamidae of southern Myanmar

    Directory of Open Access Journals (Sweden)

    George R. Zug

    2017-02-01

    Full Text Available Recent fieldwork in southern Tanintharyi revealed the presence of a small Green Crested Lizard in the wet evergreen forest. We generated mtDNA sequence data (ND2 that demonstrates that this population’s nearest relative is Bronchocela rayaensis Grismer et al., 2015 of Pulau Langkawi, northwestern Peninsular Malaysia and Phuket Island. Morphologically the Burmese Bronchocela shares many features with B. rayaensis, which potentially would make this recently described Thai-Malay species a synonym of Bronchocela burmana Blanford, 1878; however, we interpret the genetic and morphological differences to reflect evolutionary divergence and recommend the recognition of both species.

  17. Baseline values of micronuclei and comet assay in the lizard Tupinambis merianae (Teiidae, Squamata).

    Science.gov (United States)

    Schaumburg, Laura G; Poletta, Gisela L; Siroski, Pablo A; Mudry, Marta D

    2012-10-01

    The Micronucleus test (MN) and Comet assay (CA) are currently the most widely used methods that allow the characterization of DNA damage induced by physical and chemical agents in wild species. The continuous expansion of the cultivated areas in Argentina, since the introduction of transgenic crops, mainly soy, in association with the increased use of pesticides, transformed deeply the natural environments where the lizard Tupinambis merianae (tegu lizard) occurs. Despite the fact that reptiles have shown to be excellent bioindicators of environmental contaminants, there is no record of genotoxicity studies in T. merianae. The aim of the present study was to adjust the MN test and CA protocols to be applied in erythrocytes of T. merianae, and determine the baseline values of DNA damage in this species. We used 20 adult lizards (10 males: 10 females) from Estación Zoológica Experimental "Granja La Esmeralda" (Santa Fe, Argentina). Peripheral blood samples were collected from all animals and the MN test and CA applied according to the protocols established for other reptilian species. We test critical parameters of CA protocol (cell density, unwinding and electrophoresis times) using increasing concentrations of H2O2 (10, 25 and 50 μM) as a known genotoxic agent to induce DNA damage. Based on this, we determined the most suitable conditions for the CA in this species: a cell density of 4×10(3) erythrocytes per slide, 10 min of unwinding and 15 min of electrophoresis at 0.90 V/cm approximately. The baseline frequency of micronuclei (BFMN=MN/1000 erythrocytes counted) determined for this species was 0.95±0.27 and the basal damage index (BDI: calculated from 100 comet images classified in arbitrary units)=103.85±0.97. No differences were observed between sexes in the BFMN or BDI (p>0.05), and no relation was found between baseline values and length or weight of the analyzed animals (p>0.05). These results demonstrated the sensitivity of both biomarkers of

  18. Efferent projections of the septum in the Tegu lizard, Tupinambis nigropunctatus.

    Science.gov (United States)

    Sligar, C M; Voneida, T J

    1981-09-01

    A H3 proline or H3 leucine mixture was injected into the septal region of the Tegu lizard in order to determine its efferent projections. The brains were processed according to standard autoradiographic technique and counterstained with cresyl violet. Septal projections were limited to either telencephalic or diencephalic areas. Intratelencephalic projections consisted of efferents to medial pallium, nucleus accumbens, bed nucleus of the anterior commissure, preoptic area and septum itself. Fibers entering the diencephalon projected to medial habenular nucleus, dorsomedial thalamic nucleus, dorsolateral thalamic area, periventricular nucleus of the hypothalamus, lateral hypothalamic area and mammillary nucleus. The results are discussed in relation to the efferent projections of the septum in other vertebrates.

  19. Bearded dragons (Pogona vitticeps) asymptomatically infected with Devriesea agamarum are a source of persistent clinical infection in captive colonies of dab lizards (Uromastyx sp.).

    Science.gov (United States)

    Devloo, R; Martel, A; Hellebuyck, T; Vranckx, K; Haesebrouck, F; Pasmans, F

    2011-06-02

    Devriesea agamarum causes dermatitis and septicaemia in a variety of lizards, notably those belonging to the genus Uromastyx, whereas other species such as bearded dragons (Pogona vitticeps) seem to be asymptomatic carriers. Using amplified fragment length polymorphism (AFLP), the relatedness between 69 D. agamarum isolates was examined. The isolates derived from 44 diseased lizards, of which 31 belonged to the genus Uromastyx, and from 25 healthy lizards, of which 21 were bearded dragons. Eight AFLP genotypes were obtained, four of which comprised 93% of the isolates. These four genotypes were each present in 2, 2, 8 and 13 different captive colonies. Up to three genotypes were isolated from a single infected colony simultaneously. On two occasions, the same genotype was found in healthy bearded dragons and diseased Uromastyx lizards from the same colony, confirming the role of the former as an asymptomatic source of infection for the latter. Two genotypes, comprising 12 isolates, were exclusively associated with diseased Uromastyx lizards, suggesting strain dependent host adaptation. Finally, D. agamarum was shown to be able to persist for at least seven years in a lizard colony, persistently causing severe disease in several lizard species. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Analysis of a herpetofaunal community from an altered marshy area in Sicily; with special remarks on habitat use (niche breadth and overlap), relative abundance of lizards and snakes, and the correlation between predator abundance and tail loss in lizards

    NARCIS (Netherlands)

    Luiselli, L.; Angelici, F.M.; Di Vittorio, M.; Spinnato, A.; Politano, E.

    2005-01-01

    A field survey was conducted in a highly degraded barren environment in Sicily in order to investigate herpetofaunal community composition and structure, habitat use (niche breadth and overlap) and relative abundance of a snake predator and two species of lizard prey. The site was chosen because it

  1. New host and distributional records for Cryptosporidium sp. (Apicomplexa: Cryptosporidiidae) from lizards (Sauria: Gekkonidae, Scincidae) from the Cook Islands and Vanuatu, South Pacific

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.

    2013-01-01

    Between 1991 and 1993, 295 lizards, comprising 21 species in 2 families (Gekkonidae, Scincidae) from the Cook Islands, Fiji, Palau, Takapoto, and Vanuatu in the South Pacific, were examined for Cryptosporidium oocysts. Only 6 lizards (2%) were found to be passing Cryptosporidium oocysts in their feces, including 2 of 30 (7%) Oceania geckos, Gehyra oceanica, from Rarotonga, Cook Islands, and 4 of 26 (15%) Pacific blue-tailed skinks, Emoia caeruleocauda, from Efate Island, Vanuatu. This represents the largest survey for Cryptosporidium in Pacific island lizards, and we document 2 new host and 2 new locality records for this parasite genus.

  2. Molecular survey and microscopic examination of Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) in lacertid lizards from the western Mediterranean.

    Science.gov (United States)

    Maia, João P M C; Perera, Ana; Harris, D James

    2012-12-01

    The genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) is composed of intracellular haemogregarine parasites that are widely distributed among all tetrapod groups. The present study combines microscopic and molecular data on haemogregarine parasites from lizards in the western Mediterranean. We screened tissue samples and examined blood smears for the presence of species of Hepatozoon from four lizards, namely Algyroides marchi Valverde, endemic to Southeast Spain, Podarcis bocagei Seoane from Spain and Portugal, P hispanica Steindachner from Spain, and P lilfordi Günther from Cabrera, Balearic Islands (Spain). Our results show that prevalence and intensity of Hepatozoon parasites vary between and within lizard species from different regions. Algyroides marchi and P bocagei from Spain had the lowest values, whereas P hispanica had the highest. Phylogeny based on 18S rRNA gene sequences indicates that most of the new Hepatozoon sequences are part of a clade exclusive from North African and Iberian lizards, except for a single P bocagei isolate that is found related to another clade including isolates from other reptile host species and rodents. Interestingly, isolates from Algyroides form a distinct monophyletic subgroup, which could be a signal of strict host-specificity within this host genus.

  3. Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus) in northeastern Brazil.

    Science.gov (United States)

    Rocha, C F D; Cunha-Barros, M; Menezes, V A; Fontes, A f; Vrcibradic, D; Van Sluys, M

    2008-06-01

    We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts' bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100%) prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets) and ecology (especially microhabitat use).

  4. Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rocha C.F.D.

    2008-06-01

    Full Text Available We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts’ bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100% prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets and ecology (especially microhabitat use.

  5. Contrasting effects of landscape features on genetic structure in different geographic regions in the ornate dragon lizard, Ctenophorus ornatus.

    Science.gov (United States)

    Levy, Esther; Tomkins, Joseph L; Lebas, Natasha R; Kennington, W Jason

    2013-08-01

    Habitat fragmentation can have profound effects on the distribution of genetic variation within and between populations. Previously, we showed that in the ornate dragon lizard, Ctenophorus ornatus, lizards residing on outcrops that are separated by cleared agricultural land are significantly more isolated and hold less genetic variation than lizards residing on neighbouring outcrops connected by undisturbed native vegetation. Here, we extend the fine-scale study to examine the pattern of genetic variation and population structure across the species' range. Using a landscape genetics approach, we test whether land clearing for agricultural purposes has affected the population structure of the ornate dragon lizard. We found significant genetic differentiation between outcrop populations (FST  = 0.12), as well as isolation by distance within each geographic region. In support of our previous study, land clearing was associated with higher genetic divergences between outcrops and lower genetic variation within outcrops, but only in the region that had been exposed to intense agriculture for the longest period of time. No other landscape features influenced population structure in any geographic region. These results show that the effects of landscape features can vary across species' ranges and suggest there may be a temporal lag in response to contemporary changes in land use. These findings therefore highlight the need for caution when assessing the impact of contemporary land use practices on genetic variation and population structure. © 2013 John Wiley & Sons Ltd.

  6. There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

    Directory of Open Access Journals (Sweden)

    Travis J Hagey

    Full Text Available Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

  7. Transcriptomic analysis of tail regeneration in the lizard Anolis carolinensis reveals activation of conserved vertebrate developmental and repair mechanisms.

    Directory of Open Access Journals (Sweden)

    Elizabeth D Hutchins

    Full Text Available Lizards, which are amniote vertebrates like humans, are able to lose and regenerate a functional tail. Understanding the molecular basis of this process would advance regenerative approaches in amniotes, including humans. We have carried out the first transcriptomic analysis of tail regeneration in a lizard, the green anole Anolis carolinensis, which revealed 326 differentially expressed genes activating multiple developmental and repair mechanisms. Specifically, genes involved in wound response, hormonal regulation, musculoskeletal development, and the Wnt and MAPK/FGF pathways were differentially expressed along the regenerating tail axis. Furthermore, we identified 2 microRNA precursor families, 22 unclassified non-coding RNAs, and 3 novel protein-coding genes significantly enriched in the regenerating tail. However, high levels of progenitor/stem cell markers were not observed in any region of the regenerating tail. Furthermore, we observed multiple tissue-type specific clusters of proliferating cells along the regenerating tail, not localized to the tail tip. These findings predict a different mechanism of regeneration in the lizard than the blastema model described in the salamander and the zebrafish, which are anamniote vertebrates. Thus, lizard tail regrowth involves the activation of conserved developmental and wound response pathways, which are potential targets for regenerative medical therapies.

  8. Lizard Microhabitat and Microclimate Relationships in Southeastern Pine-Hardwood Forests Managed With Prescribed Burning and Thinning

    Science.gov (United States)

    W.B. Sutton; Y. Wang; C.J. Schweitzer; D.A. Steen

    2014-01-01

    Understanding the impacts of disturbances in forest ecosystems is essential for long-term biodiversity conservation. Many studies have evaluated wildlife responses to various disturbances but most generally do not use changes in microclimate features or crohabitat structure to explain these responses. We examined lizard responses to two common forest management...

  9. There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

    Science.gov (United States)

    Hagey, Travis J; Harte, Scott; Vickers, Mathew; Harmon, Luke J; Schwarzkopf, Lin

    2017-01-01

    Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

  10. Detection of zoonotic and livestock-specific assemblages of Giardia duodenalis in free-living wild lizards

    Directory of Open Access Journals (Sweden)

    Aurora Reboredo-Fernández

    Full Text Available Abstract Giardia duodenalis is a zoonotic parasite that infects the gut of a wide range of vertebrates, including numerous wildlife species. However, little is known about this protozoan parasite in reptiles. Fecal samples from 31 wild lizards were collected in Galicia (northwest Spain and screened for the presence of Giardia by PCR amplification and sequencing of the ITS1-5.8S-ITS2 region in the ribosomal unit. This allowed detection of the parasite in 5 samples (16.1%, and enabled identification of G. duodenalis assemblage A2 in two samples of Iberian rock lizard (Iberolacerta monticola, G. duodenalis assemblage B in other two samples of I. monticola, and G. duodenalis assemblage E in one sample of Bocage’s wall lizard (Podarcis bocagei. The results obtained after PCR amplification and sequencing of the SSU-rDNA gene confirmed the presence of G. duodenalis assemblage A in two samples of I. monticola. This is the first report of G. duodenalis in free-living lizards, although further studies are needed to distinguish between actual infection and mechanical dissemination of cysts. The detection of zoonotic and livestock-specific assemblages of G. duodenalis demonstrates the wide environmental contamination by this parasite, possibly due to human activities.

  11. Seasonal changes in blood oxygen transport and acid-base status in the tegu lizard, Tupinambis merianae.

    Science.gov (United States)

    Andrade, Denis V; Brito, Simone P; Toledo, Luís Felipe; Abe, Augusto S

    2004-05-20

    Oxygen-binding properties, blood gases, and acid-base parameters were studied in tegu lizards, Tupinambis merianae, at different seasons and temperatures. Independent of temperature and pH, blood oxygen affinity was higher in dormant lizards than in those active during the summer. Haematocrit (Hct) and hemoglobin content ([Hb]) were greater in active lizards resulting in a higher oxygen-carrying capacity. Nucleoside triphosphate content ([NTP]) was reduced during dormancy, but the ratio between [NTP] and [Hb] remained unchanged. Dormancy was accompanied by an increase in plasma bicarbonate ([HCO-(3)]pl) and an elevation of arterial CO2 partial pressure (PaCO2) and CO2 content in the plasma (CplCO2). These changes in acid-base parameters persist over a broad range of body temperatures. In vivo, arterial O2 partial pressure (PaO2) and O2 content (CaO2) were not affected by season and tended to increase with temperature. Arterial pH (pHa) of dormant animals is reduced compared to active lizards at body temperatures below 15 degrees C, while no significant difference was noticed at higher temperatures. Copyright 2003 Elsevier B.V.

  12. 75 FR 9377 - Endangered and Threatened Wildlife and Plants; Listing the Flat-Tailed Horned Lizard as Threatened

    Science.gov (United States)

    2010-03-02

    ... available scientific and commercial information, we request information on the flat-tailed horned lizard... commercial, recreational, scientific, or educational purposes; (c) Disease or predation; (d) The inadequacy....S. District Court for the Southern District of California challenging our 1997 withdrawal of the...

  13. Geographical variation in body size and sexual size dimorphism in an Australian lizard, Boulenger's Skink (Morethia boulengeri).

    Science.gov (United States)

    Michael, Damian R; Banks, Sam C; Piggott, Maxine P; Cunningham, Ross B; Crane, Mason; MacGregor, Christopher; McBurney, Lachlan; Lindenmayer, David B

    2014-01-01

    Ecogeographical rules help explain spatial and temporal patterns in intraspecific body size. However, many of these rules, when applied to ectothermic organisms such as reptiles, are controversial and require further investigation. To explore factors that influence body size in reptiles, we performed a heuristic study to examine body size variation in an Australian lizard, Boulenger's Skink Morethia boulengeri from agricultural landscapes in southern New South Wales, south-eastern Australia. We collected tissue and morphological data on 337 adult lizards across a broad elevation and climate gradient. We used a model-selection procedure to determine if environmental or ecological variables best explained body size variation. We explored the relationship between morphology and phylogenetic structure before modeling candidate variables from four broad domains: (1) geography (latitude, longitude and elevation), (2) climate (temperature and rainfall), (3) habitat (vegetation type, number of logs and ground cover attributes), and (4) management (land use and grazing history). Broad phylogenetic structure was evident, but on a scale larger than our study area. Lizards were sexually dimorphic, whereby females had longer snout-vent length than males, providing support for the fecundity selection hypothesis. Body size variation in M. boulengeri was correlated with temperature and rainfall, a pattern consistent with larger individuals occupying cooler and more productive parts of the landscape. Climate change forecasts, which predict warmer temperature and increased aridity, may result in reduced lizard biomass and decoupling of trophic interactions with potential implications for community organization and ecosystem function.

  14. 78 FR 7907 - Endangered and Threatened Wildlife and Plants; Removing the Island Night Lizard From the Federal...

    Science.gov (United States)

    2013-02-04

    ... establishing population and habitat baselines, or for detecting variations from those baselines over the course... snout to vent (Goldberg and Bezy 1974, p. 356; Fellers and Drost 1991, p. 28; Mautz 1993, p. 422... slow-growing, late-maturing, and long- lived lizard (Goldberg and Bezy 1974, pp. 355-358; Fellers and...

  15. Endocrine function and reproductive impairment in an irradiated population of the lizard Uta stansburiana

    International Nuclear Information System (INIS)

    Pearson, A.K.; Licht, P.; Nagy, K.A.; Medica, P.A.

    1978-01-01

    Gonadal changes in lizards (Uta stansburiana) exposed to chronic low levels of γ radiation (1.5 to 10 R/day) under field conditions are described, and attempts to evaluate endocrine involvement in these changes are made. Reproductive impairment in irradiated males was demonstrated during the breeding season by reduced testes weights and by seminiferous tubules devoid of germ cells. Ultrastructural morphology of Leydig cells, plasma testosterone levels, and developed accessory sex structures indicatedd normal steroidogenesis in such males; cytology of the pituitary gonadotropes and pituitary gonadotropin content indicated normal gonadotropin levels. These findings suggest that low levels of radiation affect the spermatogenic process directly, rather than through damage to the pituitary. Comparable irradiation caused complete resorption of ovarian tissue in some female Uta. The oviducts were atrophic and the pituitary gonadotropes hyperactive. Resemblance of gonadotropes to those of castrated animals and reduced pituitary hormone content suggests elevated levels of gonadotropin production, probably due to the absence of ovarian steroid feedback in affected animals. The continued mitotic activity of oogonia in adult reptiles and their limited number contributed to the vulnerability of germinal tissue in irradiated female lizards. Destruction of the germ cells was accompanied by resorption of all ovarian tissue including steroidogenic elements. Thus, in females as in males, radiation appears to damage gametogenesis rather than pituitary function

  16. Expression of Recombinant Human Coagulation Factor VII by the Lizard Leishmania Expression System

    Directory of Open Access Journals (Sweden)

    Sina Mirzaahmadi

    2011-01-01

    Full Text Available The variety of recombinant protein expression systems have been developed as a resource of FVII gene expression. In the current study, the authors used a novel protein expression system based on the Iranian Lizard Leishmania, a trypanosomatid protozoan as a host for expression of FVII. Plasmid containing cDNA encoding full-length human FVII was introduced into Lizard Leishmania and positive transfectants were analyzed by SDS-PAGE and Western blot analysis. Furthermore, biological activity of purified protein was detected by PT assay. The recombinant strain harboring a construct was analyzed for expression of FVII at the mRNA and protein level. Purified rFVII was obtained and in order to confirm the purified compound was in fact rFVII. Western blot analysis was carried out. Clotting time in PT assay was reduced about 30 seconds with the purified rFVII. In Conclusion, this study has demonstrated, for the first time, that Leishmania cells can be used as an expression system for producing recombinant FVII.

  17. Convergence across a continent: adaptive diversification in a recent radiation of Australian lizards.

    Science.gov (United States)

    Blom, Mozes P K; Horner, Paul; Moritz, Craig

    2016-06-15

    Recent radiations are important to evolutionary biologists, because they provide an opportunity to study the mechanisms that link micro- and macroevolution. The role of ecological speciation during adaptive radiation has been intensively studied, but radiations can arise from a diversity of evolutionary processes; in particular, on large continental landmasses where allopatric speciation might frequently precede ecological differentiation. It is therefore important to establish a phylogenetic and ecological framework for recent continental-scale radiations that are species-rich and ecologically diverse. Here, we use a genomic (approx. 1 200 loci, exon capture) approach to fit branch lengths on a summary-coalescent species tree and generate a time-calibrated phylogeny for a recent and ecologically diverse radiation of Australian scincid lizards; the genus Cryptoblepharus We then combine the phylogeny with a comprehensive phenotypic dataset for over 800 individuals across the 26 species, and use comparative methods to test whether habitat specialization can explain current patterns of phenotypic variation in ecologically relevant traits. We find significant differences in morphology between species that occur in distinct environments and convergence in ecomorphology with repeated habitat shifts across the continent. These results suggest that isolated analogous habitats have provided parallel ecological opportunity and have repeatedly promoted adaptive diversification. By contrast, speciation processes within the same habitat have resulted in distinct lineages with relatively limited morphological variation. Overall, our study illustrates how alternative diversification processes might have jointly stimulated species proliferation across the continent and generated a remarkably diverse group of Australian lizards. © 2016 The Author(s).

  18. The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus

    Science.gov (United States)

    Vitt, Laurie J.; Caldwell, Janalee P.; Zani, Peter A.; Titus, Tom A.

    1997-01-01

    We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to other T. hispidus, the rock outcrop morphology and ecology are derived within T. hispidus, and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species. PMID:9108063

  19. The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus.

    Science.gov (United States)

    Vitt, L J; Caldwell, J P; Zani, P A; Titus, T A

    1997-04-15

    We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to other T. hispidus, the rock outcrop morphology and ecology are derived within T. hispidus, and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species.

  20. Factors affecting helminths community structure of the Egyptian lizard Chalcides ocellatus (Forskal, 1775

    Directory of Open Access Journals (Sweden)

    Ibrahim M.M.

    2005-12-01

    Full Text Available The variation in the component community structure of intestinal helminths in the lizard Chalcides ocellatus (Forskal, 1775 was studied in relation to the seasonal variation and host weight and sex. 120 lizards were collected seasonally during year 2004, from Al Firdan, Ismailia governorate, Egypt. The helminths community consisted of six species (five nematodes and one cestode. The various helminths differed according to host sex. The prevalence of total helminths infection was 67.6 % while the prevalences of Thelandros schusteri, Pharyngodon mamillatus, Parapharyngodon bulbosus, Cosmocerca vrcibradici, Spauligodon petersi and Oochoristica maccoyi were 43.4 %, 3.9 %, 13.2 %, 5.3 %, 6.6 %, and 14.3 %, respectively. The results showed that the season was the main factor affecting infracommunity species richness and parasite abundance. Moreover, there was interaction between season and host sex on abundance of P. bulbosus. The prevalence of intestinal helminths varied significantly in relation to host weight classes and sex in some species. Helminths abundance and intensity were independent from host sex. In addition, correlations were found between total helminths abundance and host weight. In conclusion, the helminths community of C. ocellatus was depauperate and the influence of the studied factors varied from species to another one. We cannot say if the low species richness and infection rates observed in the present study are typical of the host species or if they are due to characteristics of the study area, since no available data on parasite assemblages exist for other C. ocellatus populations.