Graves, Gary R.
I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid.......I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid....
Esteban Fernandez-Juricic; Patrick A. Zollner; Cherie LeBlanc Fisher; Lynne M. Westphal
We assessed the effects of the presence and the frequency of canoe and pedestrian disturbance during two breeding seasons on multiple behavioral responses (scanning, freezing, grooming, sleeping, moving, wing-raising, and standing-up) of Black-crowned Night Heron ( Nycticorax nycticorax ) nestlings in a breeding colony in southeast Chicago. Short-...
Brussee, Brianne E.; Coates, Peter S.; Dwight, Ian; Young, Laura G.
During 2011, four separate instances of indirect filial cannibalism, whereby adults consumed their young that died from unknown causes, were observed using video-monitoring techniques in a nesting colony of Black-crowned Night-Herons (Nycticorax nycticorax) on Alcatraz Island. Though they were not observed actively killing their young, in all four observations adult Black-crowned Night-Herons consumed their young following death (i.e., indirect filial cannibalism). We could not determine cause of chick mortality, but parental neglect was likely a contributing factor in at least two instances. Indirect filial cannibalism is not commonly documented among birds, and understanding how cannibalism contributes to nest failure can help researchers better understand factors that limit nesting populations.
Golden, N.H.; Rattner, B.A.; Cohen, J.B.; Hoffman, D.J.; Russek-Cohen, E.; Ottinger, M.A.
Although lead can attain high concentrations in feathers, interpretation of the biological significance of this phenomenon is difficult. As part of an effort to develop and validate non-invasive methods to monitor contaminant exposure in free-ranging birds, lead uptake by feathers of nestling black-crowned night-herons (Nycticorax nycticorax) was evaluated in a controlled exposure study. Four to six day-old heron nestlings (one/nest) at Chincoteague Bay, Virginia, received a single intraperitoneal injection of dosing vehicle (control; n=7) or a dose of lead nitrate in water (0.01, 0.05, or 0.25 mg Pb/g body weight of nestling; n=6 or 7/dose) chosen to yield feather lead concentrations found at low to moderately polluted sites. Nestlings were euthanized at 15 days of age. Lead accumulation in feathers was associated with concentrations in bone, kidney, and liver (r = 0.32 - 0.74, p feather lead concentration. Culmen growth rate was depressed in nestlings treated with the highest dose of lead, but not correlated with feather lead concentration. These findings provide evidence that feathers of nestling herons are a sensitive indicator of lead exposure and have potential application for the extrapolation of lead concentrations in other tissues and the estimation of environmental lead exposure in birds.
Golden, Nancy H; Rattner, Barnett A; Cohen, Jonathan B; Hoffman, David J; Russek-Cohen, Estelle; Ottinger, Mary Ann
Although lead can attain high concentrations in feathers, interpretation of the biological significance of this phenomenon is difficult. As part of an effort to develop and validate noninvasive methods to monitor contaminant exposure in free-ranging birds, lead uptake by feathers of nestling black-crowned night herons (Nycticorax nycticorax) was evaluated in a controlled exposure study. Four- to 6-d-old heron nestlings (one/nest) at Chincoteague Bay, Virginia (USA), received a single intraperitoneal injection of dosing vehicle (control, n = 7) or a dose of lead nitrate in water (0.01, 0.05, or 0.25 mg Pb/g body wt of nestling; n = 6 or 7/dose) chosen to yield feather lead concentrations found at low- to moderately polluted sites. Nestlings were euthanized at 15 d of age. Lead accumulation in feathers was associated with concentrations in bone, kidney, and liver (r = 0.32-0.74, p feather lead concentration. Culmen growth rate was depressed in nestlings treated with the highest dose of lead but not correlated with feather lead concentration. These findings provide evidence that feathers of nestling herons are a sensitive indicator of lead exposure and have potential application for the extrapolation of lead concentrations in other tissues and the estimation of environmental lead exposure in birds.
Golden, N.H.; Rattner, B.A.; Cohen, J.B.; Hoffman, D.J.; Ottinger, M.A.
Lead is a known environmental toxicant, and poisoning resulting from the ingestion of lead shot has been well-documented in many species of waterfowl. However, much less is known regarding exposure and effects of free environmental lead in species of birds other than waterfowl. In an attempt to evaluate toxicity of lead to herons and to determine the usefulness of feathers as a non-invasive exposure-monitoring tool, black-crowned night-heron nestlings were dosed with lead to determine its distribution among tissues, and its effects on biochemical biomarkers, growth, and survival. Five-day-old heron nestlings (one per nest) at Chincoteague Bay, Virginia were given a single intra-peritoneal injection of dosing vehicle (control; N=7) or one of three lead solutions (as lead nitrate) (10, 50, or 250 mg/kg body weight of nestling; N=7 per dose) chosen to represent levels below, at, and above those found in moderately-polluted environments. All nestlings treated with lead exhibited dose-dependent inhibition of delta-aminolevulinic acid dehydratase (ALAD) activity compared to controls, and nestlings treated with the highest concentration showed a reduced carcass weight compared to controls. Of several measures of oxidative stress that were analyzed, significant differences were found between low- and high-dosed nestlings in hepatic total thiol and protein-bound sulfhydryl concentrations. No differences in survival were detected between dosed nestlings, controls, or uninjected siblings. Lead concentrations in several matrices, including feathers, are being determined to assess distribution among tissues and will also be examined for relationships with measures of effect.
Custer, Thomas W.; Golden, Nancy H.; Rattner, Barnett A.
The pattern of elements in nestling black-crowned night-heron feathers from a rural Minnesota colony differed from colonies in industrialized regions of Maryland and Delaware. Except for chromium, however, the differences did not reflect the elements associated with waters and sediments of the Maryland and Delaware colonies. Therefore, elements in water and sediment do not necessarily bioaccumulate in night-heron feathers in relation to potential exposure. Although trace element patterns in feathers indicated differences among geographical locations, they did not separate all locations well and their usefulness as an indicator of natal colony location may be limited.
Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs
McKernan, Moira A.; Rattner, Barnett A.; Hatfield, Jeff S.; Hale, Robert C.; Ottinger, Mary Ann
We recently reported that air cell administration of penta-brominated diphenyl ether (penta-BDE; DE-71) evokes biochemical and immunologic effects in chicken (Gallus gallus) embryos at very low doses, and impairs pipping (i.e., stage immediately prior to hatching) and hatching success at 1.8 ug g-1 egg (actual dose absorbed) in American kestrels (Falco sparverius). I n the present study, absorption of polybrominated diphenyl ether (PBDE) congeners was measured following air cell administration of a penta-BDE mixture (11.1 ug DE-71 g-1 egg) or an octa-brominated diphenyl ether mixture (octa-BDE; DE-79; 15.4 ug DE-79 g-1 egg). Uptake of PBDE congeners was measured at 24 h post-injection, midway through incubation, and at pipping in chicken, mallard (Anas platyrhynchos), and American kestrel egg contents, and at the end of incubation in black-crowned night-heron (Nycticorax nycticorax) egg contents. Absorption of penta-BDE and octa-BDE from the air cell into egg contents occurred throughout incubation; at pipping, up to 29.6% of penta-BDE was absorbed, but only 1.40-6.48% of octa-BDE was absorbed. Higher brominated congeners appeared to be absorbed more slowly than lower brominated congeners, and uptake rate was inversely proportional to the log Kow of predominant BDE congeners. Six congeners or co-eluting pairs of congeners were detected in penta-BDE-treated eggs that were not found in the dosing solution suggesting debromination in the developing embryo, extraembryonic membranes, and possibly even in the air cell membrane. This study demonstrates the importance of determining the fraction of xenobiotic absorbed into the egg following air cell administration for estimation of the lowest-observed-effect level.
Hill, Elwood F.; Henry, Charles J.; Grove, Robert A.
Mercury concentrations in the floodplain of the Carson River Basin in northwestern Nevada are some of the highest ever reported in a natural system. Thus, a portion of the basin including Lahontan Reservoir was placed on the U.S. Environmental Protection Agency’s Natural Priorities List for research and cleanup. Preliminary studies indicated that reproduction in piscivorous birds may be at risk. Therefore, a 10-year study (1997–2006) was conducted to evaluate reproduction of snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) nesting on Gull Island in Lahontan Reservoir. Special attention was given to the annual flow of the Carson River, the resultant fluctuation of this irrigation reservoir, and the annual exposure of snowy egrets and night-herons to methylmercury (MeHg). The dynamic character of the river due to flooding and drought (drought effect) influenced snowy egret and night-heron reproduction more so than did MeHg contamination of eggs. During an extended drought (2000–2004) in the middle of the study, snowy egret nests containing eggs with concentrations of MeHg (measured as total mercury [THg] ∼ 100% MeHg) ≥0.80 μg THg/g, ww, all failed, but in 1997 and 2006 (wet years with general flooding), substantial numbers of young were produced (but fewer than at nests where eggs contained reproductive threshold of tolerance to MeHg may be associated with habitat quality (food type and abundance). Clearly, drought was the most important factor affecting snowy egret annual productivity. In contrast to snowy egrets, night-herons generally had fewer nests meeting the 0.80 μg THg/g criterion, and those above the criterion were less sensitive to mercury than were snowy egrets. Furthermore, night-herons appeared more tolerant of drought conditions than snowy egrets because they nested earlier, selected more protected nesting sites, and had a more generalist diet that provided additional food options including terrestrial
Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillitt, D.E.
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins, induced up to 85-fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r-2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah-active PCB congeners, and presumably other compounds, which interact similarly with the Ah receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.
Mercury and drought along the Lower Carson River, Nevada: III. effects on blood and organ biochemistry and histopathology of snowy egrets and black-crowned night-herons on Lahontan Reservoir, 2002-2006
Hoffman, David J.; Henny, Charles J.; Hill, Elwood F.; Grove, Robert A.; Kaiser, James L.; Stebbins, Katherine R.
A 10-year study (1997-2006) was conducted to evaluate reproduction and health of aquatic birds in the Carson River Basin of northwestern Nevada (on the U.S. Environmental Protection Agency Natural Priorities List) due to high mercury (Hg) concentrations from past mining activities. This part of the study evaluated physiological associations with blood Hg in young snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax), and organ biochemistry and histopathological effects in snowy egrets on Lahontan Reservoir (LR) from the period 2002-2006. LR snowy egret geometric mean total Hg concentrations (μg/g ww) ranged from 1.5 to 4.8 for blood, 2.4 to 3.1 liver, 1.8 to 2.5 kidneys, 1.7 to 2.4 brain, and 20.5 to 36.4 feathers over these years. For night-herons, mean Hg for blood ranged from 1.6 to 7.4. Significant positive correlations were found between total Hg in blood and five plasma enzyme activities of snowy egrets suggesting hepatic stress. Histopathological findings revealed vacuolar changes in hepatocytes in LR snowy egrets as well as correlation of increased liver inflammation with increasing blood and tissue Hg. Hepatic oxidative effects were manifested by decreased hepatic total thiol concentration and glutathione reductase activity and elevated hepatic thiobarbituric acid-reactive substances (TBARS), a measure of lipid peroxidation. However, other hepatic changes indicated compensatory mechanisms in response to oxidative stress, including decreased oxidized glutathione (GSSG) concentration and decreased ratio of GSSG to reduced glutathione. In young black-crowned night-herons, fewer correlations were apparent. In both species, positive correlations between blood total Hg and plasma uric acid and inorganic phosphorus were suggestive of renal stress, which was supported by histopathological findings. Both oxidative effects and adaptive responses to oxidative stress were apparent in kidneys and brain. Vacuolar change and inflammation in
Combined impacts of Black-crowned Night-Heron predation/disturbance and various management activities on Roseate Tern productivity in 2003, and testing of a video surveillance system for recording the diurnal and nocturnal behavior of terns and night-herons at Falkner Island, Stewart B. McKinney National Wildlife Refuge, Connecticut, in 2004: Report to U.S. Fish and Wildlife Service, Stewart B. McKinney National Wildlife Refuge, Westbrook, Connecticut and U.S. Fish and Wildlife Service, Region 5 Regional Office, Hadley, Massachusetts
Spendelow, J.A.; Kuter, M.
Falkner Island (FICT), a unit of the U.S. Fish and Wildlife Service's Stewart B. McKinney National Wildlife Refuge (SBMNWR) since 1985, is located in Long Island Sound 5 km south of Guilford, CT. For more than three decades it has been the site of the only large breeding colony in Connecticut of the federally endangered Northwest Atlantic population of Roseate Terns (Sterna dougallii) and the state's largest colony of Common Terns (S. hirundo). Both species have been studied at this site since 1978 as part of the Falkner Island Tern Project (FITP), and since 1987 also as part of a regional Cooperative Roseate Tern Metapopulation Dynamics and Ecology Project (CRTMP), both coordinated by Dr. Jeffrey A. Spendelow of the U.S. Geological Survey's Patuxent Wildlife Research Center (USGS-PWRC). From 1997-2002 the Roseate Tern breeding population at this site declined by more than 50% from about 150 to about 70 nesting pairs, mostly as a result of the nocturnal predation and disturbance of tern chicks and eggs by Black-crowned Night-Herons (Nycticorax nycticorax). Here we report the results of research done with the goal of improving management of nocturnal predators and developing new practices/structures to reduce losses of tern eggs and chicks so as to prevent the abandonment of this site by Roseate Terns. Notification of release of the USGS 'Quick Response Funds' (QRF) that were to be used to support the part of this study entitled 'Nocturnal behavior/interactions of endangered Roseate Terns and Black-crowned Night-Herons', and final approval of the Study Plan for this research did not occur until after the breeding season in 2003 was well underway. As a result, some work will need to be completed during the 2004 field season. There are two major objectives of this study. The first is to collect basic information (a) on the nocturnal behavior and interactions of Roseate (and Common) Terns with predatory Black-crowned Night-Herons, and (b) on how the behavior of the
Joaquim O. Branco
Full Text Available O savacu Nycticorax nycticorax (Linnaeus, 1758 é uma espécie de hábitos crepusculares e noturnos, com ampla distribuição geográfica. Sua biologia reprodutiva tem sido intensivamente estudada nos países de ocorrência, entretanto, no Brasil, é comumente citada nos levantamentos de ornitólogos, mas não existem informações disponíveis sobre seu ciclo de vida. Esse trabalho objetiva contribuir para o conhecimento da biologia reprodutiva dessa espécie no litoral catarinense. As amostragens foram realizadas nos anos de 2000 a 2002 na Ilha dos Pássaros e de 2002 na Ilha dos Lobos, Santa Catarina. As maiores abundâncias de exemplares e ninhos com ovos ocorreram em outubro, sendo que o comprimento médio dos ovos variou entre 5,02 ± 0,23 a 5,07 ± 0,21 cm e o volume 31,71 ± 2,64 a 35,92 ± 3,47 cm³ e as maiores freqüências de filhotes em novembro, culminando o abandono da colônia em meados de janeiro. Foram identificados sete itens nos regurgitos dos filhotes, sendo que os peixes marinhos representaram 44,4% da massa total. O principal predador na colônia foi o urubu-comum, que atuou sobre os ovos no início da temporada e os filhotes no final.The black-crowned night heron N. nycticorax (Linnaeus, 1758 is a aquatic bird with twilight and night habits, with wide geographical distribution. His reproductive biology has been studied intensively at the occurrence countries, however, in Brazil, it is mentioned commonly in the ornithologists' risings, but available information don't exist on his life cycle. This work aims to contribute for the knowledge of the reproductive biology of that species in the Santa Catarina coast. The samplings were accomplished in the years from 2000 to 2002 in the Ilha dos Pássaros and of 2002 in the Ilha dos Lobos, Santa Catarina. The largest abundances of individuals and nests with eggs happened in October, and the medium length of the eggs varied between 5.02 ± 0.23 to 5.07 ± 0.21 cm and the volume 31
Custer, Thomas W; Dummer, Paul M; Custer, Christine M; Franson, J Christian; Jones, Michael
In earlier studies, elevated concentrations of polychlorinated biphenyl (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE) were reported in double-crested cormorant (Phalacrocorax auritus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings collected from lower Green Bay (WI, USA) in 1994 and 1995 and black-crowned night-heron (Nycticorax nycticorax) eggs collected in 1991. Comparable samples collected in 2010 and 2011 indicated that concentrations of PCBs were 35%, 62%, 70%, and 88% lower than in the early 1990s in tree swallow eggs, tree swallow nestlings, double-crested cormorant eggs, and black-crowned night-heron eggs, respectively; concentrations of DDE were 47%, 43%, 51%, and 80% lower, respectively. These declines are consistent with regional contaminant trends in other species. Concentrations of PCBs were higher in herring gull (Larus argentatus) than in black-crowned night-heron eggs collected from Green Bay in 2010; PCB concentrations in double-crested cormorant and tree swallow eggs were intermediate. The estimated toxicity of the PCB mixture in eggs of the insectivorous tree swallow was the equal to or greater than toxicity in the 3 piscivorous bird species. A multivariate analysis indicated that the composition percentage of lower-numbered PCB congeners was greater in eggs of the insectivorous tree swallow than in eggs of the 3 piscivorous species nesting in Green Bay. Dioxin and furan concentrations and the toxicity of these chemicals were also higher in tree swallows than these other waterbird species nesting in Green Bay. Published 2014 Wiley Periodicals, Inc.
Custer, T.W.; Custer, Christine M.; Eichhorst, B.A.; Warburton, D.
Exceptionally high cadmium (Cd) and chromium (Cr) concentrations were reported in eggs, feathers, or livers of selected waterbird species nesting at Agassiz National Wildlife Refuge (Agassiz) in 1994. Ten- to 15-day-old Franklin's gull (Larus pipixcan), black-crowned night-heron (Nycticorax nycticorax), and eared grebe (Podiceps nigricollis) chicks were collected in 1998, 1999, and 2001 at Agassiz and analyzed for selenium (Se) and metals including Cd and Cr. Freshly laid eggs were collected in 2001 from Franklin's gull, black-crowned night-heron, eared grebe, and pied-billed grebe (Podilymbus podiceps) nests at Agassiz. Based on a multivariate analysis, the pattern of Se and metal concentrations differed among species for eggs, chick feathers, and chick livers. Low Cd and Cr concentrations were measured in eggs, chick livers, and chick feathers of all four species. Mercury concentrations in black-crowned night-heron and eared grebe eggs collected from Agassiz in 2001 were lower than concentrations reported in 1994. Se and metal concentrations, including Cd and Cr, in waterbird eggs and chicks collected at Agassiz in 1998, 1999, and 2001 were not at toxic levels. ?? 2007 Springer Science+Business Media, LLC.
Hothem, R.L.; Roster, D.L.; King, K.A.; Keldsen, T.J.; Marois, Katherine C.; Wainwright, S.E.
Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p'-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time, At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.
Burger, J; Gochfeld, M
Several species of herons and egrets frequently nest in colonies in areas where humans also concentrate. Since the birds feed on intermediate-sized fish that themselves concentrate pollutants, they can be used not only to assess the levels of contaminants in avian tissues but as indicators of contaminants in the environment. The concentration of heavy metals and selenium in the breast feathers of fledgling black-crowned night herons Nycticorax nycticorax and Chinese pond herons Ardeola bacchus from the Tu Jing Yan heronry outside Chengdu, Szechuan Province in China; and from fledgling black-crowned night heron, little egret Egretta garzetta, great egret Egretta alba and cattle egret Bubulcus ibis from the Mai Po heronry in Hong Kong, were determined. Breast feathers were also collected from adult great egrets in Hong Kong. Adult great egrets had significantly higher levels of all heavy metals than did young great egrets. There were no significant interspecific differences in metal levels among the young at Szechuan China, except for chromium (pond herons had higher levels). There were significant differences among the young nesting at Hong Kong for all metals examined. Great egrets had lower, and night herons had higher, levels of lead than the other young. Night herons also had the highest levels of cadmium, manganese, and selenium compared to the other young. Great egret chicks had the lowest mercury levels, while little egret had the highest levels. Lead levels for all the birds in both Hong Kong and Szechuan were among the highest in the world, and this was attributed to the continued use of leaded gasoline.
Brussee, Brianne E.; Coates, Peter S.; Hothem, Roger L.; Howe, Kristy; Casazza, Michael L.; Eadie, John M.
Studies of avian nest success often focus on examining influences of variation in environmental and seasonal factors. However, in-depth evaluations can also incorporate variation in individual incubation behaviour to further advance our understanding of avian reproductive ecology. We examined these relationships in colonially nesting Black-crowned Night-Herons Nycticorax nycticorax using intensive video-monitoring methods to quantify incubation behaviours. We modelled nest survival as a function of both extrinsic factors and incubation behaviours over a 3-year period (2010–12) on Alcatraz Island, USA. Model-averaged parameter estimates indicated that nest survival increased as a function of greater incubation constancy (% of time spent incubating eggs within a 24-h period), and average daily precipitation throughout the nesting stage. Common Ravens Corvus corax are the only known nest predator of Night-Herons on Alcatraz Island, as on many other coastal Pacific islands. We also investigated the effects of heterospecific nesting of California Gulls Larus californicus and Western Gulls Larus occidentalis in a mixed-species colony with Night-Herons, based on nesting proximity data collected over a 2-year period (2011–12). This second analysis indicated that, in addition to incubation behaviours, nesting heterospecifics are an important factor for explaining variation in Night-Heron nest survival. However, contrary to our original expectation, we found that Night-Herons experienced increased nest survival with increasing distance from gull colony boundaries. These results may apply to other areas with multiple colonial nesting species and similar predator communities and climatic patterns.
Wiemeyer, Stanley N.; Hoffman, D.J.
Raptors are occasionally exposed to excessive selenium from contaminated prey, but the effects of this exposure on reproduction are unknown. Therefore, we fed captive eastern screech-owls (Otus asio) diets containing 0, 4.4, or 13.2 ppm (wet wt) added selenium in the form of seleno-DL-methionine. Adult mass at sacrifice and reproductive success of birds receiving 13.2 ppm selenium were depressed (P biochemistries indicative of oxidative stress were affected (P < 0.05) in 5-day-old nestlings from parents fed 4.4 ppm selenium and included a 19% increase in glutathione peroxidase activity, a 43% increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), and a 17% increase in lipid peroxidation. Based on reproductive effects relative to dietary exposure, sensitivity of eastern screech-owls to selenium was similar to that of black-crowned night-herons (Nycticorax nycticorax) but less than that of mallards (Anas platyrhynchos).
Reisen, William K; Wheeler, Sarah; Armijos, M Veronica; Fang, Ying; Garcia, Sandra; Kelley, Kara; Wright, Stan
Although herons and egrets in the family Ardeidae frequently have been associated with viruses in the Japanese encephalitis virus serocomplex, communal nesting colonies do not appear to be a focus of early season and rapid amplification of West Nile virus (WNV) in California. Evidence for repeated WNV infection was found by testing living and dead nestlings collected under trees with mixed species ardeid colonies nesting above in an oak grove near the University of California arboretum in Davis and in a Eucalyptus grove at a rural farmstead. However, mosquito infection rates at both nesting sites were low and positive pools did not occur earlier than at comparison sites within the City of Davis or at the Yolo Bypass wetlands managed for rice production and waterfowl habitat. Black-crowned night herons (Nycticorax nycticorax) were the most abundant and frequently infected ardeid species, indicating that WNV may be an important cause of mortality among nestlings of this species.
Hothem, R.L.; Crayon, J.J.; Law, M.A.
Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels-black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)-generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded
1. Intestinal absorption of a polychlorinated biphenyl, dieldrin, and mercury (from HgCl2) was measured in adult Northern bobwhites, Eastern screech owls, American kestrels, black-crowned night-herons and mallards in vivo by an in situ luminal perfusion technique.2. Bobwhites, screech owls and kestrels absorbed much more of each xenobiotic than black-crowned night-herons and mallards.3. Mallards absorbed less dieldrin and mercury than black-crowned night-herons.4. Mercury absorption by kestrels was more than twice that in screech owls and eight times that observed in mallards.5. Pronounced differences in xenobiotic absorption rates between bobwhites, screech owls and kestrels on the one hand, and black-crowned night-herons and mallards on the other, raise the possibility that absorptive ability may be associated with the phylogenetic classification of birds.
Henny, Charles J.; Anderson, T.W.; Crayon, J.J.
The Salton Sea is a highly eutrophic, hypersaline terminal lake that receives inflows primarily from agricultural drainages in the Imperial and Coachella valleys. Impending reductions in water inflow at Salton Sea may concentrate existing contaminants which have been a concern for many years, and result in higher exposure to birds. Thus, waterbird eggs were collected and analyzed in 2004 and compared with residue concentrations from earlier years; these data provide a base for future comparisons. Eggs from four waterbird species (black-crowned night-heron [Nycticorax nycticorax], great egret [Ardea alba], black-necked stilt [Himantopus mexicanus], and American avocet [Recurvirostra Americana]) were collected. Eggs were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), metals, and trace elements, with current results compared to those reported for eggs collected from the same species and others during 1985a??1993. The two contaminants of primary concern were p,pa??-DDE (DDE) and selenium. DDE concentrations in night-heron and great egret eggs collected from the northwest corner of Salton Sea (Whitewater River delta) decreased 91 and 95%, respectively, by 2004, with a concomitant increase in eggshell thickness for both species. Decreases in bird egg DDE levels paralleled those in tissues of tilapia (Oreochromis mossambicus ?? O. urolepis), an important prey species for herons and egrets. Despite most nests of night-herons and great egrets failing in 2004 due to predation, predicted reproductive effects based on DDE concentrations in eggs were low or negligible for these species. The 2004 DDE findings were in dramatic contrast to those in the past decade, and included an 81% decrease in black-necked stilt eggs, although concentrations were lower historically than those reported in night-herons and egrets. Selenium concentrations in black-necked stilt eggs from the southeast corner of Salton Sea (Davis Road) were similar in 1993 and 2004, with 4
Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillett, D.E.
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from undisturbed (Chincoteague National Wildlife Refuge, VA) and industrialized (Cat Island, Green Bay, WI; San Francisco Bay, CA) locations. Hepatic P450 associated monooxygenases (AHH, EROD, BROD, ECOD) and P450 proteins (CYP1A, CYP2B) were induced up to 85-fold, and were associated with burdens of total PCBs and 11 AHH-active PCB congeners. Dioxin equivalents (TCDD-EQs) of sample extracts, derived by bioassay (H4I1E rat hepatoma cell) and mathematically (product of PCB congener concentration and relative TCDD potency), revealed greatest TCDD-EQs in Cat Island samples. TCDD-EQs were associated with P450s, especially BROD, EROD and CYP1A (r2 = 0.35 to 0.66). TCDD-EQs derived by bioassay were highly correlated with TCDD-EQs derived mathematically (r2 = 0.58 to 0.67) . Multiple regressions were also performed to investigate relationships among P450s and PCB congeners. In summary, these data demonstrate that hepatic P450s of heron embryos are biomarkers of exposure to dioxin-like compounds and provide further evidence that this species has considerable value for assessing wetland and estuarine contamination.
Wainwright, S.E.; Mora, M.A.; Sericano, J.L.; Thomas, P.
During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and great egrets (Ardea alba) were similar to those found in other parts of North America; however, nesting success of black-crowned night-herons (Nycticorax nycticorax) was lower, very likely due to flooding of the nesting area. Except for DDE and toxaphene, all chlorinated pesticides in bird eggs were low and not of concern for negative effects on any of the three species. DDE was highest in green heron eggs and seemed to increase along a geographic gradient from west to east, with eggs from Falcon Reservoir containing low concentrations, and those at Los Indios containing the highest concentrations (approx. 11,000 ng/g WW), near or above the threshold for reproductive impairment. DDE levels in great egrets and black-crowned night-herons were below those that are associated with reproductive impairment. Mean DDE levels in carp at the JAS Farms site were above the threshold level suggested for predator protection. Toxaphene was detected in about 20% of the samples with high levels observed in green heron eggs from Los Indios (mean = 4,402 ng/g WW). These are the highest toxaphene levels reported in bird eggs in the LRGV. Toxaphene levels in fish ranged between 90 and 312 ng/g WW. In general, PCBs in bird eggs and fish tissue were low and at levels not of concern for reproductive effects. The greatest concentrations of testosterone and 11-ketotestosterone were detected in fish from the JAS Farms site, which also had the greatest concentrations of DDE. Increased androgen production and gonad development in fish at this site, relative to Pharr, could be possibly associated with
Zhou, Yihui; Yin, Ge; Asplund, Lillemor; Stewart, Kathryn; Rantakokko, Panu; Bignert, Anders; Ruokojärvi, Päivi; Kiviranta, Hannu; Qiu, Yanling; Ma, Zhijun; Bergman, Åke
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are highly toxic to humans and wildlife. In the present study, PCDD/Fs were analyzed in the eggs of whiskered terns (Chlidonias hybrida), and genetically identified eggs from black-crowned night herons (Nycticorax nycticorax) sampled from two lakes in the Yangtze River Delta area, China. The median toxic equivalent (TEQ) of PCDD/Fs were 280 (range: 95-1500) and 400 (range: 220-1100) pg TEQ g -1 lw (WHO, 1998 for birds) in the eggs of black-crowned night heron and whiskered tern, respectively. Compared to known sources, concentrations of PCDDs relative to the sum of PCDD/Fs in bird eggs, demonstrated high abundance of octachlorodibenzo-p-dioxin (OCDD), 1,2,3,4,6,7,8-heptaCDD and 1,2,3,6,7,8-hexaCDD indicating pentachlorophenol (PCP), and/or sodium pentachlorophenolate (Na-PCP) as significant sources of the PCDD/Fs. The presence of polychlorinated diphenyl ethers (PCDEs), hydroxylated and methoxylated polychlorinated diphenyl ethers (OH- and MeO-PCDEs, known impurities in PCP products), corroborates this hypothesis. Further, significant correlations were found between the predominant congener CDE-206, 3'-OH-CDE-207, 2'-MeO-CDE-206 and OCDD, indicating a common origin. Eggs from the two lakes are sometimes used for human consumption. The WHO health-based tolerable intake of PCDD/Fs is exceeded if eggs from the two lakes are consumed regularly on a weekly basis, particularly for children. The TEQs extensively exceed maximum levels for PCDD/Fs in hen eggs and egg products according to EU legislation (2.5 pg TEQ g -1 lw). The results suggest immediate action should be taken to manage the contamination, and further studies evaluating the impacts of egg consumption from wild birds in China. Likewise, studies on dioxins and other POPs in common eggs need to be initiated around China. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Mora, Miguel A.
The hypothesis that migratory birds accumulate persistent organochlorine pesticides (POPs) during the winter in Latin America has been prevalent for many years, particularly since 1,1,1-trichloro-2,2–bis(p-chlorophenyl)ethane (DDT) was banned in the United States in 1972. It has been suggested that peregrine falcons (Falco peregrinus), black-crowned night herons (Nycticorax nycticorax), white-faced ibises (Plegadis chihi), various migratory waterfowl and shorebirds, and other avian species accumulate higher concentrations of POPs while on migration or on their wintering grounds in Latin America. Nonetheless, the data obtained thus far are limited, and there is no clear pattern to suggest that such accumulation occurs on a widespread basis. In this review wildlife contaminant studies conducted along the U.S.-Mexico border and throughout Mexico are discussed. The results for the most part seem to indicate that no major accumulation of 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene) (DDE), the most persistent organochlorine compound, has occurred or been reported for most parts of Mexico. The majority of the DDE values in birds from Mexico were similar to those reported in birds from the southwestern United States during the same years. More work needs to be done, particularly in those cotton-producing areas of Mexico where DDT was applied heavily in the past (e.g., Chiapas and Michoacan). Because DDT is still used for malaria control and may still be used in agriculture in Chiapas, this state is probably the one where most migrant species would still be at a significant risk of increased accumulation of DDE and DDT.
Hoffman, D.J.; Henny, C.J.; Hill, E.F.; Keith, J.A.; Grove, R.A.
High concentrations of mercury from past mining activities have accumulated in the food chain of fish-eating birds nesting along the mid to lower Carson River. Activities of nine plasma and tissue enzymes, and concentrations of other plasma and tissue constituents were measured for black-crowned night-heron, Nycticorax nycticorax, (BCNH) and snowy egret, Egretta thula, (SE) nestlings from two high mercury sites and one low mercury site. Geometric mean blood Hg concentrations for BCNHs at the high mercury sites were 2.6 and 2.8 ppm (ww) and 0.6 ppm at the low mercury site. Blood concentrations for SEs were 3.6 and 1.9 ppm at the high mercury sites and 0.7 ppm at the low mercury site. In BCNHs plasma glutathione peroxidase (GSH peroxidase) activity was lower in both high mercury sites relative to the low mercury site. Butyryl cholinesterase (BuChe), ALT, glutathione reductase (GSSG-reductase) and LDH-L activities were lower in one high mercury site. In SEs significant differences were lower BuChe and LDH-L, but elevated GGT activities. Evidence of renal stress in both species at high mercury sites included increased plasma uric acid, blood urea nitrogen, and creatinine concentrations as well as oxidative stress in the kidney tissue itself where oxidized glutathione increased. A number of the mercury site-related effects, including decreased plasma GSH-peroxidase and hepatic G-6-PDH activities, higher GSSG-reductase activity, and lower hepatic concentrations of reduced thiols have been reported in methylmercury feeding studies with great egrets and mallards. These findings suggest the utility of herons and egrets for monitoring mercury sites.
Full Text Available Laguna de Cuyutlán, in the state of Colima, Mexico, is the only large coastal wetland in a span of roughly 1150 km. Despite this, the study of its birds has been largely neglected. Between 2003 and 2006 we assessed the waterbirds nesting in the middle portion of Laguna Cuyutlán, a large tropical coastal lagoon, through field visits. We documented the nesting of 15 species of non-Laridae waterbirds: Neotropic Cormorant (Phalacrocorax brasilianus, Tricolored Egret (Egretta tricolor, Snowy Egret (Egretta thula, Little Blue Heron (Egretta caerulea, Great Egret (Ardea alba, Cattle Egret (Bubulcus ibis, Black-crowned Nightheron (Nycticorax nycticorax, Yellow-crowned Night-heron (Nyctanassa violacea, Green Heron (Butorides virescens, Roseate Spoonbill (Platalea ajaja, White Ibis (Eudocimus albus, Black-bellied Whistling-duck (Dendrocygna autumnalis, Clapper Rail (Rallus longirostris, Snowy Plover (Charadrius alexandrinus, and Black-necked Stilt (Himantopus mexicanus. These add to six species of Laridae known to nest in that area: Laughing Gulls (Larus atricilla, Royal Terns (Thalasseus maximus, Gull-billed Terns (Gelochelidon nilotica, Forster’s Terns (S. forsteri, Least Terns (Sternula antillarum, and Black Skimmer (Rynchops niger, and to at least 57 species using it during the non-breeding season. With such bird assemblages, Laguna Cuyutlán is an important site for waterbirds, which should be given conservation status. Rev. Biol. Trop. 56 (1: 391-397. Epub 2008 March 31.Durante la prospección de la parte media de la Laguna Cuyutlán, una gran laguna costera en Colima, México, entre 2003 y 2006, documentamos la anidación de 15 especies de aves acuáticas que no pertenecer a la familia Laridae: Phalacrocorax brasilianus, Egretta tricolor, Egretta thula, Egretta caerulea, Ardea alba, Bubulcus ibis, Nycticorax nycticorax, Nyctanassa violacea, Butorides virescens, Platalea ajaja, Eudocimus albus, Dendrocygna autumnalis, Rallus longirostris
Henny, Charles J.; Hill, E.F.; Hoffman, D.J.; Spalding, Marilyn G.; Grove, Robert A.
Contemporary mercury interest relates to atmospheric deposition, contaminated fish stocks and exposed fish-eating wildlife. The focus is on methylmercury (MeHg) even though most contamination is of inorganic (IoHg) origin. However, IoHg is readily methylated in aquatic systems to become more hazardous to vertebrates. In response to a classic episode of historical (1859a??1890) IoHg contamination, we studied fish-eating birds nesting along the lower Carson River, Nevada. Adult double-crested cormorants (Phalacrocorax auritus), snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) contained very high concentrations of total mercury (THg) in their livers (geo. means 134.8g/g wet weight (ww), 43.7 and 13.5, respectively) and kidneys (69.4, 11.1 and 6.1, respectively). Apparently tolerance of these concentrations was possible due to a threshold-dependent demethylation coupled with sequestration of resultant IoHg. Demethylation and sequestration processes also appeared to have reduced the amount of MeHg redistributed to eggs. However, the relatively short time spent by adults in the contaminated area before egg laying was also a factor in lower than expected concentrations of mercury in eggs. Most eggs (100% MeHg) had concentrations below 0.80g/g ww, the putative threshold concentration where reproductive problems may be expected; there was no conclusive evidence of mercury-related depressed hatchability. After hatching, the young birds were fed diets by their parents averaging 0.36a??1.18gMeHg/g ww through fledging. During this four to six week period, accumulated mercury concentrations in the organs of the fledglings were much lower than found in adults, but evidence was detected of toxicity to their immune (spleen, thymus, bursa), detoxicating (liver, kidneys) and nervous systems. Several indications of oxidative stress were also noted in the fledglings and were most apparent in young cormorants containing highest concentrations of
Henny, C.J.; Hill, E.F.; Hoffman, D.J.; Spalding, M.G.; Grove, R.A.
Contemporary mercury interest relates to atmospheric deposition, contaminated fish stocks and exposed fish-eating wildlife. The focus is on methylmercury (MeHg) even though most contamination is of inorganic (IoHg) origin. However, IoHg is readily methylated in aquatic systems to become more hazardous to vertebrates. In response to a classic episode of historical (1859-1890) IoHg contamination, we studied fish-eating birds nesting along the lower Carson River, Nevada. Adult double-crested cormorants (Phalacrocorax auritus), snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) contained very high concentrations of total mercury (THg) in their livers (geo. means 134.8 g/g wet weight [ww], 43.7, and 13.5, respectively) and kidneys (69.4, 11.1, and 6.1, respectively). Apparently tolerance of these concentrations was possible due to post-absorption demethylation and sequestration of resultant IoHg. Demethylation and sequestration processes also appeared to have reduced the amount of MeHg redistributed to eggs. However, the relatively short time spent by adults in the contaminated area before egg laying was also a factor in lower than expected concentrations of mercury in eggs. Most eggs (100% MeHg) had concentrations below 0.80 g/g ww, the putative threshold concentration where reproductive problems may be expected; there was no conclusive evidence of depressed hatchability. After hatching, the young birds were fed diets by their parents averaging 0.36 to 1.18 gMeHg/g ww through fledging. During this four to six week period, accumulated mercury concentrations in the organs of the fledglings were much lower than found in adults, but evidence was detected of toxicity to their immune (spleen, thymus, bursa), detoxicating (liver, kidneys) and nervous systems. Several indications of oxidative stress were also noted in the fledglings and were most apparent in young cormorants containing highest concentrations of mercury. This stress was
Frank, D.S.; Mora, M.A.; Sericano, J.L.; Blankenship, Alan L.; Kannan, K.; Giesy, J.P.
Eggs of neotropic cormorants (Phalacrocorax brasilianus), black-crowned night herons (Nycticorax nycticorax), and great egrets (Ardea alba) nesting on several locations in Galveston Bay (TX, USA) and at two control sites outside the bay were collected during April–May 1996 and analyzed for chlorinated pesticides, PCBs, polychlorinated dibenzo-p-dioxins, and polychlor-inated dibenzofurans. Additionally, concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs) were determined by use of relative potency factors (TEQs) or the H4IIE-luc bioassay TCDD-EQs. Concentrations of 1,1,-dichloro-2,2-bis(p-chlo-rophenyl)ethylene (DDE) were greater in eggs of neotropic cormorants from Alexander Island (mean = 1,040 ng/g wet wt) in the Houston Ship Channel (Houston, TX, USA) and in those from Telfair Island (mean = 1,460 ng/g wet wt), a reference location outside the bay, than in most locations inside the bay (mean range = 119–453 ng/g wet wt). Mean PCB concentrations were greater in eggs of neotropic cormorants from Alexander Island (mean = 5,720 ng/g wet wt) than in eggs of cormorants from areas farther away from the ship channel, including two reference sites outside the bay (mean range = 404–3,140 ng/g wet wt). The TCDD was the main dioxin congener detected in eggs from all locations within Galveston Bay. Instrumental TEQs in eggs ranged from 67 pg/g wet weight at control sites to 452 pg/g wet weight at Alexander Island. Concentrations of TCDD-EQs determined in the H4IIE assay were correlated with instrumental TEQs and were greater in eggs of cormorants from islands within the bay, although these were farther away from the ship channel. Overall, concentrations of DDE, PCBs, TCDD, and TCDD-EQs were less than the threshold levels known to affect reproduction. However, some eggs contained concentrations of total PCBs or DDE greater than what would elicit adverse effects on birds. No identifiable deformities or abnormalities were detected in embryos
Dennis Denis Ávila
Gompertz equations were adjusted to data using non-lineal regression models with adult values as the asymptote. For each species, the following were determined and recorded: growth rate, age at inflexion, instantaneous growth rates at each age interval, and time taken to reach 90% of adult size. Reported hatchling sizes were similar in other localities, with a variation coefficient ranging between 10-19%. At hatch, each species exhibited differing sizes relative to adult values. In all cases, Gompertz equations were best fitted to explain more variance and lesser residuals. Rates of weight change and tarsus growth were alometrically related to the log of adult weight. Two main growth processes were identified: a physical extension in dimensions of each measure ment reflecting inter-specific morphometric differences, and a lineal increase of the growth period from Green Heron to Great Egret. The Black-crowned Night Heron, Cattle Egret and Reddish Egret exhibited some unique measurement characteristics in comparison to the remaining members of the family. All results support the hypothesis that hypermorphosis, as the main evolutionary process in the microevolution of Ardeidae, is caused by a delayed final moment of growth. Rev. Biol. Trop. 59 (2: 771-787. Epub 2011 June 01.
Rogers, C.J.; Spendelow, J.A.; Guilfoyle, Michael P.; Fischer, Richard A.; Pashley, David N.; Lott, Casey A.
subterranean channels, especially in the main revetment area, made it difficult to measure chick growth and productivity as had been done for more than 12 years prior to construction. Also, observations of color-banded adults that were unable to locate and feed their young inside the main revetment, and of adults returning to courtship behavior and renesting after having hatched chicks from their initial clutches, indicated that a minimum of 20% of the chicks (mostly first hatched A-chicks, which usually have high rates of survival to fledging) that entered the main revetment died after doing so in 2001. The mortality rate of Roseate Tern chicks that entered the secondary revetment on the southwest shelf, however, was not unusually high in 2001. In an attempt to reduce the likelihood of nesting and chick losses in these sub-colonies, a research team led by the USGS in 2002-2003 did not put nest boxes on the northeast and east shelf areas where previous losses had been high. However, losses of tern eggs and young chicks to predatory Black-crowned Night Herons (Nycticorax nycticorax) were so great in 2002?2003 that few Roseate Tern chicks survived long enough to move into the main revetment area and little comparative survival data were collected. The USFWS continues to remove predatory night herons, to monitor the location and success of nesting Roseate Terns and to fill in some of problem areas near the tern nests in the main revetment. The extensive chick-searching fieldwork and observational procedures used by the USGS-led research team to determine the growth and survival of the Roseate Tern chicks at Falkner Island were not used in 2004?2005. The number of chicks lost in the revetment during these years is not known. Without additional fill, loss of chicks of this endangered species in the main revetment may rise again even though the night heron predation problem has been reduced.
Recher, H.F.; Holmes, R.T.
Five species of diurnal herons are common on the Magela Creek flood plain and forage along the edges of natural and artifical waterbodies both inside and outside the Ranger Uranium Project Area. The species of heron differ in the kinds and sizes of prey they take, their foraging location, degree of sociality and foraging behaviour. Because it takes relatively large fish, the Great Egret, E. alba, is most likely to be affected by any contamination of the aquatic environment by heavy metals or radionuclides. The Nankeen Night Heron, Nycticorax caledonicus is also abundant on the flood plain and probably feeds on large fish and frogs. The other herons take smaller or immature prey or hunt mostly in terrestrial habitats and are therefore less likely to be affected by contamination of the aquatic environment
Rocky Flats Environmental Technology Site (Site) is located on the Colorado Piedmont east of the Front Range between Boulder and Golden. At an elevation of approximately 6,000 feet, the Site contains a unique ecotonal mixture of mountain and prairie plant species, resulting from the topography and close proximity to the mountain front. The Buffer Zone surrounding the Industrial Area is one of the largest remaining undeveloped areas of its kind along the Colorado Piedmont. A number of plant communities at the Site have been identified as increasingly rare and unique by Site ecologists and the Colorado Natural Heritage Program (CNHP). These include the xeric tallgrass prairie, tall upland shrubland, wetlands, and Great Plains riparian woodland communities. Many of these communities support populations of increasingly rare animals as well, including the Preble's meadow jumping mouse, grasshopper sparrow, loggerhead shrike, Merriam's shrew, black crowned night heron, and Hops blue and Argos skipper butterflies. One of the more interesting and important plant communities at the Site is the tall upland shrubland community. It has been generally overlooked by previous Site ecological studies, probably due to its relatively small size; only 34 acres total. Although mentioned in a plant community ordination study conducted by Clark et al. and also in the Site baseline ecological study, few data were available on this plant community before the present study
Rocky Flats Environmental Technology Site (Site) is located on the Colorado Piedmont east of the Front Range between Boulder and Golden. At an elevation of approximately 6,000 feet, the Site contains a unique ecotonal mixture of mountain and prairie plant species, resulting from the topography and close proximity to the mountain front. The Buffer Zone surrounding the Industrial Area is one of the largest remaining undeveloped areas of its kind along the Colorado Piedmont. A number of plant communities at the Site have been identified as increasingly rare and unique by Site ecologists and the Colorado Natural Heritage Program (CNHP). These include the xeric tallgrass prairie, tall upland shrubland, wetlands, and Great Plains riparian woodland communities. Many of these communities support populations of increasingly rare animals as well, including the Preble`s meadow jumping mouse, grasshopper sparrow, loggerhead shrike, Merriam`s shrew, black crowned night heron, and Hops blue and Argos skipper butterflies. One of the more interesting and important plant communities at the Site is the tall upland shrubland community. It has been generally overlooked by previous Site ecological studies, probably due to its relatively small size; only 34 acres total. Although mentioned in a plant community ordination study conducted by Clark et al. and also in the Site baseline ecological study, few data were available on this plant community before the present study.
Jahir Hussain, K.; Satpathy, K.K.; Prasad, M.V.R.; Ramesh, T.; Selvanayagam, M.
A rapid assessment of biodiversity in the DAE campus, Kalpakkam was carried out. The entire DAE campus of 3000 acres, at Kalpakkam was divided into four representative plots comprising of different landscapes namely (1) undisturbed area with dense vegetation, (2) building area, (3) water bodies with riparian cover and (4) sandy area with meager vegetation for inventorying of charismatic terrestrial/semi-aquatic fauna viz., Mammals, Birds, Reptiles, Amphibians and Butterflies. For birds, early morning surveys were made whereas for mammals evening and night surveys were followed. Midday sampling was followed for butterflies and other animals. Each plot was surveyed twice in a week over a period of one year (April 07' to March 08'). Totally 128 species of animals were identified during the survey and it has highlighted the potential of biodiversity in the campus. The diversity of butterflies is remarkable. Twenty-two butterfly species were encountered. Frogs, toads, lizards and snakes are also diverse. Five species of frogs and one species of toad were recorded. Lizards are more diverse than snakes. Nine species of lizards were encountered. Calotus versicolor is abundant followed by common skink. Totally five species of snakes were recorded. Among them Common bronzedback and Green Vine Snake were predominant. Seventy species of birds were recorded during the survey period. Black crowned night heron, Common house crow, Great cormorant, Oriental white ibis, Painted stork, Cattle egret, Common mynah are more common. Sixteen species of mammals were encountered during the survey. Wild cattle, Jackal, Jungle cat, Toddy cat, Crested porcupine and Indian civet are the major wildlife found. Indian civet and Crested porcupine are elusive animals that are diminishing from wild and their presence at this campus is an indication of less human intervention. (author)
There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey) did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ► Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ► Levels of cadmium and lead decreased significantly from 1989–2011. ► Mercury levels in feathers from great egrets did not decline from 1989–2011. ► Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets
Rajchard, J.; Balounová, Z.; Novák, R.; Kindlmann, Pavel
Roč. 26, č. 1 (2007), s. 64-67 ISSN 1335-342X R&D Projects: GA AV ČR IAA6093105; GA AV ČR(CZ) KSK6005114 Keywords : extreme flooding * night heron * spoonbill * little egret * shrubs Subject RIV: EH - Ecology, Behaviour Impact factor: 0.085, year: 2005
civilian and military flights. Since 1985, nearly 38,000 bird-military aircraft collisions have been reported. These collisions have killed 33 pilots...stations in the contiguous United States. Edges of the circles are at 124 nautical mile range (230 km). and 2004, approximately 194 people were killed ... Mockingbird Wilson’s Snipe Pileated Woodpecker American Wigeon Red-bellied Woodpecker American Coot Red-cockaded Woodpecker Black-crowned Night
Redescription of Chabaudacuaria multispinosa (Pérez Vigueras, 1938) n. g., n. comb. (Nematoda: Spirurida: Acuariidae) based on specimens from Ardea herodias L. and Nyctanassa violacea (L.) (Ardeidae) in Florida.
Mutafchiev, Yasen; Kinsella, John M
Chabaudacuaria n. g. is erected, as monotypic, for C. multispinosa (Pérez Vigueras, 1938) n. comb. (Spirurida: Acuariidae) [syns Cheilospirura multispinosa Pérez Vigueras, 1938; Acuaria multispinosa (Pérez Vigueras, 1938) Yamaguti, 1961]. This species, a parasite of various ardeid birds, is redescribed by means of light and scanning electron microscopy based on material from great blue herons Ardea herodias L. and yellow-crowned night herons Nyctanassa violacea (L.) in Florida, USA. Chabaudacuaria n. g. resembles Acuaria Bremser, 1811, Cheilospirura Diesing, 1861, Skrjabinocerca Schikhobalova, 1930 and Xenocordon Mawson, 1982 in its straight cordons which do not anastomose. However, it can be distinguished from them by the didelphic-prodelphic uterus and the absence of caudal alae in the males. In the pattern of its cordons (consisting of a row of plates and a longitudinal ridge) and the absence of an area rugosa, the new genus is similar to Chevreuxia Seurat, 1918, Syncuaria Gil'bert, 1927, Aviculariella Wehr, 1931, Skrjabinocara Kurashvili, 1940, Decorataria Sobolev, 1949 and Desportesius Chabaud & Campana, 1949, which are characterised by anastomosing cordons. The didelphic-prodelphic female reproductive system of Chabaudacuaria is intermediate between the didelphic-amphidelphic uterus of Chevreuxia and the monodelphic-prodelphic uterus of Syncuaria, Aviculariella, Skrjabinocara, Desportesius and Decorataria. Therefore, the straight and non-anastomosing cordons are considered to be autapomorphic for Chabaudacuaria.
Full Text Available Since the 90s, censuses of wintering waterfowl have been carried out in the main wetlands of Lazio. We analysed the trends of 31 species in the 1993-2006 period (base year 1993 by means of TRIM (Trends and Indices Monitoring data software (Model 3. Among the species regularly recorded in the region, Ardea alba, Ardea cinerea, Bubulcus ibis and Anser anser showed a strong increase; Podiceps cristatus, Nycticorax nycticorax, Egretta garzetta, Phoenicopterus ruber, Anas penelope, Anas strepera, Anas crecca, Anas platyrhynchos, Anas clypeata, Netta rufina, Aythya ferina, Aythya nyroca, Circus aeruginosus, Fulica atra, Pluvialis apricaria and Vanellus vanellus showed a moderate increase; Gavia arctica, Tachybaptus ruficollis, Podiceps nigricollis, Phalacrocorax carbo, Aythya fuligula and Numenius arquata resulted “stable”; Botaurus stellaris, Tadorna tadorna, Anas acuta, Pluvialis squatarola and Calidris alpina showed an uncertain trend. The trends for most species are similar to those recorded at a national level.
Navarro, Pilar; Lluch, Javier; Font, Enrique
We studied the helminth communities in 6 sympatric species of Ardeidae (Ixobrychus minutus (Linnaeus, 1766), Nycticorax nycticorax (Linnaeus, 1758), Bubulcus ibis (Linnaeus, 1758), Egretta garzetta (Linnaeus, 1766), Ardea cinerea (Linnaeus, 1758), and Ardea purpurea (Linnaeus, 1766)) from "La Albufera de Valencia," Spain. The survey revealed 13 species of helminth parasites: 5 digeneans, 2 cestodes, and 6 nematodes. The component helminth communities of the Ardeidae examined are depauperate and conform to the pattern typically found in isolationist communities, probably because of their high trophic dependence on a few prey species. Evenness was positively correlated with richness and abundance, but host body weight was not correlated with the number of helminth species or with the total number of helminths. Ardea cinerea is more heavily infected than E. garzetta by Apharyngostrigea cornu, and B. ibis is more heavily infected than both Ardea cinerea and E. garzetta by Desportesius spinulatus. Apharyngostrigea cornu was positively associated with Desmidocercella numidica and D. spinulatus in A. cinerea.
Dennis Denis Ávila
Full Text Available El crecimiento en aves forma parte de las estrategias reproductivas y su implicación ecológica ha sido profundamente debatida. En este trabajo se describe el crecimiento del pico, peso y tarso de ocho garzas (Aves: Ardeidae en la ciénaga de Birama, Cuba. Para ello, entre 1998-2006, se midieron en días alternos un total de 714 pichones de Butorides virescens, Bubulcus ibis, Egretta thula, E. tricolor, E. caerulea, E. rufescens, Ardea alba y Nycticorax nycticorax, durante sus dos primeras semanas de vida. Se hicieron ajustes a las curvas Logística y de Gompertz y se usó regresiones no lineales y valores adultos como asíntotas, además se determinaron las variables que describenel crecimiento. El tamaño de los pichones al eclosionar fue similar al encontrado en otras localidades, con CV entre 10-19% y diferencias relativas al tamaño adulto. Las ecuaciones de Gompertz tuvieron menos residuos en todos los casos. Entonces, se identificaron dos procesos fundamentales de extensión en el crecimiento de cada estructura: uno físico y otro de duración, entre B. virescens y E. alba. Nycticorax, B. ibis y E. rufescens mostraron variaciones que los diferenciaron del resto. Los resultados apoyan la hipótesis de la microevolución de Ardeidae por hipermorfosis, por un retardo en el momento final del crecimiento.
Discovery of seven novel Mammalian and avian coronaviruses in the genus deltacoronavirus supports bat coronaviruses as the gene source of alphacoronavirus and betacoronavirus and avian coronaviruses as the gene source of gammacoronavirus and deltacoronavirus.
Woo, Patrick C Y; Lau, Susanna K P; Lam, Carol S F; Lau, Candy C Y; Tsang, Alan K L; Lau, John H N; Bai, Ru; Teng, Jade L L; Tsang, Chris C C; Wang, Ming; Zheng, Bo-Jian; Chan, Kwok-Hung; Yuen, Kwok-Yung
Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus, Deltacoronavirus, in the subfamily Coronavirinae. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sparrow coronavirus HKU17, magpie robin coronavirus HKU18, night heron coronavirus HKU19, wigeon coronavirus HKU20, and common moorhen coronavirus HKU21. Complete genome sequencing and comparative genome analysis showed that the avian and mammalian deltacoronaviruses have similar genome characteristics and structures. They all have relatively small genomes (25.421 to 26.674 kb), the smallest among all coronaviruses. They all have a single papain-like protease domain in the nsp3 gene; an accessory gene, NS6 open reading frame (ORF), located between the M and N genes; and a variable number of accessory genes (up to four) downstream of the N gene. Moreover, they all have the same putative transcription regulatory sequence of ACACCA. Molecular clock analysis showed that the most recent common ancestor of all coronaviruses was estimated at approximately 8100 BC, and those of Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus were at approximately 2400 BC, 3300 BC, 2800 BC, and 3000 BC, respectively. From our studies, it appears that bats and birds, the warm blooded flying vertebrates, are ideal hosts for the coronavirus gene source, bats for Alphacoronavirus and Betacoronavirus and birds for Gammacoronavirus and Deltacoronavirus, to fuel coronavirus evolution and dissemination.
Nathan D Burkett-Cadena
Full Text Available Seasonal shifts in host use by mosquitoes from birds to mammals drive the timing and intensity of annual epidemics of mosquito-borne viruses, such as West Nile virus, in North America. The biological mechanism underlying these shifts has been a matter of debate, with hypotheses falling into two camps: (1 the shift is driven by changes in host abundance, or (2 the shift is driven by seasonal changes in the foraging behavior of mosquitoes. Here we explored the idea that seasonal changes in host use by mosquitoes are driven by temporal patterns of host reproduction. We investigated the relationship between seasonal patterns of host use by mosquitoes and host reproductive phenology by examining a seven-year dataset of blood meal identifications from a site in Tuskegee National Forest, Alabama USA and data on reproduction from the most commonly utilized endothermic (white-tailed deer, great blue heron, yellow-crowned night heron and ectothermic (frogs hosts. Our analysis revealed that feeding on each host peaked during periods of reproductive activity. Specifically, mosquitoes utilized herons in the spring and early summer, during periods of peak nest occupancy, whereas deer were fed upon most during the late summer and fall, the period corresponding to the peak in births for deer. For frogs, however, feeding on early- and late-season breeders paralleled peaks in male vocalization. We demonstrate for the first time that seasonal patterns of host use by mosquitoes track the reproductive phenology of the hosts. Peaks in relative mosquito feeding on each host during reproductive phases are likely the result of increased tolerance and decreased vigilance to attacking mosquitoes by nestlings and brooding adults (avian hosts, quiescent young (avian and mammalian hosts, and mate-seeking males (frogs.
Full Text Available In this paper are showed the results of the researches performed during February 2013 – January 2014 on the avifauna from the Vâlcele Basin. The 65 observed species belong to 13 orders, Passeriformes being the richest (33 species. Anseriformes and Charadriiformes (each with 7 species were the best represented among the wetland birds. 5 species (Podiceps cristatus, Phalacrocorax carbo, Anas platyrhynchos, Fulica atra, and Larus argentatus cachinnans/michahellis were euconstant and 2 species (Anas platyrhynchos and Fulica atra were eudominant. Anas platyrhynchos counted most individuals in a month in December; in July were no individuals. Fulica atra had the most number in September; it was absent in May. For the Vâlcele Basin avicoenose, Anseriformes and Gruiformes were the overdominat orders and, inside the Anseriformes order, Anas platyrhynchos was overdominant species. 7 species (Egretta alba, Nycticorax nycticorax, Ciconia ciconia, Chlidonias hybridus, Alcedo atthis, Picus canus, and Lanius collurio are in the Annex I of the Birds Directive.
Depredación de aves acuáticas por la nutria neotropical (Lontra longicaudis annectens, en el río Yaqui, Sonora, México Aquatic bird predation by neotropical river otter (Lontra longicaudis annectens, at Rio Yaqui, Sonora, Mexico
Juan Pablo Gallo-Reynoso
Full Text Available Se registra la depredación de aves acuáticas por la nutria neotropical (L. longicaudis annectens en el río Yaqui, Sonora. Se colectaron e identificaron 25 cráneos, porciones de esqueleto postcraneal y plumas de aves encontrados en los comederos de las nutrias; las especies identificadas fueron el cormorán neotropical (Phalacrocorax brasilianus con 16 individuos, el pato de collar (Anas platyrhynchos diazi, 4 individuos; la garza blanca (Ardea alba, 3 individuos; el huaco de corona amarilla (Nyctanassa violacea y el pelícano café (Pelecanus occidentalis, ambos con 1 individuo. En los peces se encontró la tilapia del género Oreochromis. Probablemente los hábitos alimenticios de esta especie responden a la estacionalidad y al consumo de presas más disponibles en el hábitat. Estos registros confirman que las nutrias de río son depredadores oportunistas cuya dieta tiene una amplio rango de uso de especies de los ambientes riparios, además dichos registros son una razón más para considerar la nutria neotropical como especie sombrilla para la conservación de ecosistemas completos, ya que su presencia es un indicador de alta disponibilidad energética y de alta biodiversidad.We report the predation of aquatic birds by neotropical river otters (L. longicaudis annectens at Río Yaqui, Sonora. As many as 25 skulls, post-cranial skeletons and feathers were found at river otter feeding sites. The neotropical cormorant (Phalacrocorax brasilianus was the most predated bird with 16 individuals, followed by Mexican mallard (Anas platyrhynchos diazi with 4 individuals, great egret (Ardea alba with 3 individuals, yellow-crowned night-heron (Nyctanassa violacea, and brown pelican (Pelecanus occidentalis, both with 1 individual. With respect to fish, the tilapia Oreochromis, was the only species found in scats. Neotropical river otter feeding habits were associated with food availability at different seasons of the year. These records show that
Full Text Available Registramos la presencia y abundancia de aves, así como el hábitat y temporalidad de la reproducción de especies en las islas Pájaros, Venados, Lobos, Hermano Norte y Hermano Sur, ubicadas en la bahía de Mazatlán. Realizamos siete recorridos entre noviembre de 2014 y mayo de 2015; además contábamos con información colectada en mayo de 2004. Observamos un total de 59 especies de aves, de las cuales 15 fueron reproductoras: Dendrocygna autumnalis (pijije ala blanca, Phaethon aethereus (rabijunco pico rojo, Sula leucogaster (bobo café, Pelecanus occidentalis (pelícano café, Ardea herodias (garza morena, Ardea alba (garza blanca, Egretta thula (garza pie dorado, Bubulcus ibis (garza ganadera, Nycticorax nycticorax (pedrete corona negra, Nyctanassa violacea (pedrete corona clara, Eudocimus albus (ibis blanco, Coragyps atratus (zopilote común, Haematopus palliatus (ostrero americano, Larus heermanni (gaviota ploma y Falco peregrinus (halcón peregrino. Para P. aethereus y S. leucogaster no había reportes previos de reproducción en estas islas; además, confirmamos la anidación de L. hermanni. La isla Pájaros fue la que albergó el mayor número de especies reproductoras (10 especies. Pelecanus occidentalis fue la especie más abundante con un total de 1 559 individuos, seguido de Fregata magnificens (fragata magnífica y Sula nebouxii (bobo pata azul con 1 526 y 1 100 individuos, respectivamente; aunque para estas dos últimas especies no hubo registros de reproducción. Las islas se encuentran bajo protección, pero se requiere realizar monitoreos para establecer el estado y tendencias de las poblaciones de aves, así como los efectos de las perturbaciones por actividades humanas y por las especies introducidas.
Full Text Available During 1997-1999, a total of 94 crabs, Uca rapax were collected from La Sabana, La Ceiba and El Paujil, Sucre State, Venezuela. Of these 36 were infected with metacercariae. Two parasites were located in the abdominal muscles and one under the tissue of carapace and gonad. These metacercariae grew to adults in the following genera: Levinseniella, Microphallus and Maritrema, in the period of 2-5 days after feeding experimentally to the rat Rattus norvegicus, mice Mus musculus and duck Cairinia moschata. Specimens of the genus Microphallus were described herein as a new species M. sabanensis. The life cycle of M. sabanensis sp.nov. were studied experimentally using rat, mice and duck. All developmental stages and the adult are described. In addition, M. sabanensis was collected from wild birds Anas discors, Pluvialis squatarola, Butorides striatus, Egretta caerulea and Nycticorax violaceus from the same localitiesDurante 1997-1999, se recolectaron en La Sabana, La Ceiba y El Paujil del Distrito Cajigal, Estado Sucre, Venezuela, un total de 94 cangrejos Uca rapax, 36 de ellos estaban parasitados con tres especies de metacercarias de digéneos. Dos de ellos localizados en la musculatura del abdomen y una en el tejido que recubre internamente el caparazón y las gónadas. Estas metacercarias fueron dadas como alimento a ratones Mus musculus, ratas Rattus norvegicus, y patos Cairina moschata y tres genéros de microfálidos, Levinseniella, Microphallus y Maritrema fueron recuperados del intestino delgado de estos animales después de 2-5 días de la infección. Especimenes del genero Microphallus de este estudio se describen como Microphallus sabanensis sp.n. Se estudió experimentalmente los aspectos de ciclo vida de la especie, utilizando ratas, ratones y patos. Se describen todas las estapas larvales y los adultos. Además, M. sabanensis se encuentra naturalmente en las aves: Anas discors, Pluvialis squatarola, Butorides striatus, Egretta caerulea