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Sample records for bird evolution testing

  1. Testing adaptive regime shifts for range size evolution of endemic birds of China

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    Youhua Chen

    2016-03-01

    Full Text Available In this brief report, adaptive regime shifts for the range size evolution of the endemic birds of China were identified. Four models with different biological meanings were tested and compared through maximum likelihood models, including the Brownian motion model, one global optimal range size model for all lineages in the phylogeny, two optimal regime model of range sizes for lineages with large and small range sizes (OU2, and three optimal regime model in which an additional regime is added to the ancestral lineages. The results of model evaluation and comparison using the maximum likelihood technique show that over 48 endemic taxa, two optimal regimes (the OU2 model were observed for bird lineages with large and small range sizes in the country. The possible reasons for such an observation were outlined accordingly, including the different evolutionary times, which were subjected to different historical and geological conditions, heterogeneous environmental conditions, and complex climatic fluctuations. Overall, the range size evolution of the endemic taxa was subjected to multiple selective stresses. For future implications, more studies are desired to provide a holistic view of the evolution and divergence of endemic taxa.

  2. Current perspectives on the evolution of birds

    NARCIS (Netherlands)

    Ericson, P.G.P.

    2008-01-01

    The paper summarizes the current understanding of the evolution and diversification of birds. New insights into this field have mainly come from two fundamentally different, but complementary sources of information: the many newly discovered Mesozoic bird fossils and the wealth of genetic analyses o

  3. Temporal genomic evolution of bird sex chromosomes

    DEFF Research Database (Denmark)

    Wang, Zongji; Zhang, Jilin; Yang, Wei;

    2014-01-01

    BACKGROUND: Sex chromosomes exhibit many unusual patterns in sequence and gene expression relative to autosomes. Birds have evolved a female heterogametic sex system (male ZZ, female ZW), through stepwise suppression of recombination between chrZ and chrW. To address the broad patterns and complex...... driving forces of Z chromosome evolution, we analyze here 45 newly available bird genomes and four species' transcriptomes, over their course of recombination loss between the sex chromosomes. RESULTS: We show Z chromosomes in general have a significantly higher substitution rate in introns and synonymous...... ('fast-Z' evolution). And species with a lower level of intronic heterozygosities tend to evolve even faster on the Z chromosome. Further analysis of fast-evolving genes' enriched functional categories and sex-biased expression patterns support that, fast-Z evolution in birds is mainly driven by genetic...

  4. Rates of morphological evolution are heterogeneous in Early Cretaceous birds.

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    Wang, Min; Lloyd, Graeme T

    2016-04-13

    The Early Cretaceous is a critical interval in the early history of birds. Exceptional fossils indicate that important evolutionary novelties such as a pygostyle and a keeled sternum had already arisen in Early Cretaceous taxa, bridging much of the morphological gap between Archaeopteryx and crown birds. However, detailed features of basal bird evolution remain obscure because of both the small sample of fossil taxa previously considered and a lack of quantitative studies assessing rates of morphological evolution. Here we apply a recently available phylogenetic method and associated sensitivity tests to a large data matrix of morphological characters to quantify rates of morphological evolution in Early Cretaceous birds. Our results reveal that although rates were highly heterogeneous between different Early Cretaceous avian lineages, consistent patterns of significantly high or low rates were harder to pinpoint. Nevertheless, evidence for accelerated evolutionary rates is strongest at the point when Ornithuromorpha (the clade comprises all extant birds and descendants from their most recent common ancestors) split from Enantiornithes (a diverse clade that went extinct at the end-Cretaceous), consistent with the hypothesis that this key split opened up new niches and ultimately led to greater diversity for these two dominant clades of Mesozoic birds.

  5. Recurrent DCC gene losses during bird evolution

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    Friocourt, François; Lafont, Anne-Gaelle; Kress, Clémence; Pain, Bertrand; Manceau, Marie; Dufour, Sylvie; Chédotal, Alain

    2017-01-01

    During development, midline crossing by axons brings into play highly conserved families of receptors and ligands. The interaction between the secreted ligand Netrin-1 and its receptor Deleted in Colorectal Carcinoma (DCC) is thought to control midline attraction of crossing axons. Here, we studied the evolution of this ligand/receptor couple in birds taking advantage of a wealth of newly sequenced genomes. From phylogeny and synteny analyses we can infer that the DCC gene has been conserved in most extant bird species, while two independent events have led to its loss in two avian groups, passeriformes and galliformes. These convergent accidental gene loss events are likely related to chromosome Z rearrangement. We show, using whole-mount immunostaining and 3Disco clearing, that in the nervous system of all birds that have a DCC gene, DCC protein expression pattern is similar to other vertebrates. Surprisingly, we show that the early developmental pattern of commissural tracts is comparable in all birds, whether or not they have a DCC receptor. Interestingly, only 4 of the 5 genes encoding secreted netrins, the DCC ligands in vertebrates, were found in birds, but Netrin-5 was absent. Together, these results support a remarkable plasticity of commissural axon guidance mechanisms in birds. PMID:28240285

  6. Temporal genomic evolution of bird sex chromosomes

    DEFF Research Database (Denmark)

    Wang, Zongji; Zhang, Jilin; Yang, Wei;

    2014-01-01

    BACKGROUND: Sex chromosomes exhibit many unusual patterns in sequence and gene expression relative to autosomes. Birds have evolved a female heterogametic sex system (male ZZ, female ZW), through stepwise suppression of recombination between chrZ and chrW. To address the broad patterns and complex...... driving forces of Z chromosome evolution, we analyze here 45 newly available bird genomes and four species' transcriptomes, over their course of recombination loss between the sex chromosomes. RESULTS: We show Z chromosomes in general have a significantly higher substitution rate in introns and synonymous...... changes with that of introns, between chrZ and autosomes or regions with increasing ages of becoming Z-linked, therefore codon usage bias in birds is probably driven by the mutational bias. On the other hand, Z chromosomes also evolve significantly faster at nonsynonymous sites relative to autosomes...

  7. Testing for adaptive evolution of the female reproductive protein ZPC in mammals, birds and fishes reveals problems with the M7-M8 likelihood ratio test

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    Berlin Sofia

    2005-11-01

    Full Text Available Abstract Background Adaptive evolution appears to be a common feature of reproductive proteins across a very wide range of organisms. A promising way of addressing the evolutionary forces responsible for this general phenomenon is to test for adaptive evolution in the same gene but among groups of species, which differ in their reproductive biology. One can then test evolutionary hypotheses by asking whether the variation in adaptive evolution is consistent with the variation in reproductive biology. We have attempted to apply this approach to the study of a female reproductive protein, zona pellucida C (ZPC, which has been previously shown by the use of likelihood ratio tests (LRTs to be under positive selection in mammals. Results We tested for evidence of adaptive evolution of ZPC in 15 mammalian species, in 11 avian species and in six fish species using three different LRTs (M1a-M2a, M7-M8, and M8a-M8. The only significant findings of adaptive evolution came from the M7-M8 test in mammals and fishes. Since LRTs of adaptive evolution may yield false positives in some situations, we examined the properties of the LRTs by several different simulation methods. When we simulated data to test the robustness of the LRTs, we found that the pattern of evolution in ZPC generates an excess of false positives for the M7-M8 LRT but not for the M1a-M2a or M8a-M8 LRTs. This bias is strong enough to have generated the significant M7-M8 results for mammals and fishes. Conclusion We conclude that there is no strong evidence for adaptive evolution of ZPC in any of the vertebrate groups we studied, and that the M7-M8 LRT can be biased towards false inference of adaptive evolution by certain patterns of non-adaptive evolution.

  8. Evolution of olfaction in non-avian theropod dinosaurs and birds.

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    Zelenitsky, Darla K; Therrien, François; Ridgely, Ryan C; McGee, Amanda R; Witmer, Lawrence M

    2011-12-22

    Little is known about the olfactory capabilities of extinct basal (non-neornithine) birds or the evolutionary changes in olfaction that occurred from non-avian theropods through modern birds. Although modern birds are known to have diverse olfactory capabilities, olfaction is generally considered to have declined during avian evolution as visual and vestibular sensory enhancements occurred in association with flight. To test the hypothesis that olfaction diminished through avian evolution, we assessed relative olfactory bulb size, here used as a neuroanatomical proxy for olfactory capabilities, in 157 species of non-avian theropods, fossil birds and living birds. We show that relative olfactory bulb size increased during non-avian maniraptoriform evolution, remained stable across the non-avian theropod/bird transition, and increased during basal bird and early neornithine evolution. From early neornithines through a major part of neornithine evolution, the relative size of the olfactory bulbs remained stable before decreasing in derived neoavian clades. Our results show that, rather than decreasing, the importance of olfaction actually increased during early bird evolution, representing a previously unrecognized sensory enhancement. The relatively larger olfactory bulbs of earliest neornithines, compared with those of basal birds, may have endowed neornithines with improved olfaction for more effective foraging or navigation skills, which in turn may have been a factor allowing them to survive the end-Cretaceous mass extinction.

  9. Evolution of the hippocampus in reptiles and birds.

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    Striedter, Georg F

    2016-02-15

    Although the hippocampus is structurally quite different among reptiles, birds, and mammals, its function in spatial memory is said to be highly conserved. This is surprising, given that structural differences generally reflect functional differences. Here I review this enigma in some detail, identifying several evolutionary changes in hippocampal cytoarchitecture and connectivity. I recognize a lepidosaurid pattern of hippocampal organization (in lizards, snakes, and the tuatara Sphenodon) that differs substantially from the pattern of organization observed in the turtle/archosaur lineage, which includes crocodilians and birds. Although individual subdivisions of the hippocampus are difficult to homologize between these two patterns, both lack a clear homolog of the mammalian dentate gyrus. The strictly trilaminar organization of the ancestral amniote hippocampus was gradually lost in the lineage leading to birds, and birds expanded the system of intrahippocampal axon collaterals, relative to turtles and lizards. These expanded collateral axon branches resemble the extensive collaterals in CA3 of the mammalian hippocampus but probably evolved independently of them. Additional examples of convergent evolution between birds and mammals are the loss of direct inputs to the hippocampus from the primary olfactory cortex and the general expansion of telencephalic regions that communicate reciprocally with the hippocampus. Given this structural convergence, it seems likely that some similarities in the function of the hippocampus between birds and mammals, notably its role in the ability to remember many different locations without extensive training, likewise evolved convergently. The currently available data do not allow for a strong test of this hypothesis, but the hypothesis itself suggests some promising new research directions.

  10. Sexual selection accelerates signal evolution during speciation in birds

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    Seddon, Nathalie; Botero, Carlos A.; Tobias, Joseph A.; Dunn, Peter O.; MacGregor, Hannah E. A.; Rubenstein, Dustin R.; Uy, J. Albert C.; Weir, Jason T.; Whittingham, Linda A.; Safran, Rebecca J.

    2013-01-01

    Sexual selection is proposed to be an important driver of diversification in animal systems, yet previous tests of this hypothesis have produced mixed results and the mechanisms involved remain unclear. Here, we use a novel phylogenetic approach to assess the influence of sexual selection on patterns of evolutionary change during 84 recent speciation events across 23 passerine bird families. We show that elevated levels of sexual selection are associated with more rapid phenotypic divergence between related lineages, and that this effect is restricted to male plumage traits proposed to function in mate choice and species recognition. Conversely, we found no evidence that sexual selection promoted divergence in female plumage traits, or in male traits related to foraging and locomotion. These results provide strong evidence that female choice and male–male competition are dominant mechanisms driving divergence during speciation in birds, potentially linking sexual selection to the accelerated evolution of pre-mating reproductive isolation. PMID:23864596

  11. Predictable evolution toward flightlessness in volant island birds.

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    Wright, Natalie A; Steadman, David W; Witt, Christopher C

    2016-04-26

    Birds are prolific colonists of islands, where they readily evolve distinct forms. Identifying predictable, directional patterns of evolutionary change in island birds, however, has proved challenging. The "island rule" predicts that island species evolve toward intermediate sizes, but its general applicability to birds is questionable. However, convergent evolution has clearly occurred in the island bird lineages that have undergone transitions to secondary flightlessness, a process involving drastic reduction of the flight muscles and enlargement of the hindlimbs. Here, we investigated whether volant island bird populations tend to change shape in a way that converges subtly on the flightless form. We found that island bird species have evolved smaller flight muscles than their continental relatives. Furthermore, in 366 populations of Caribbean and Pacific birds, smaller flight muscles and longer legs evolved in response to increasing insularity and, strikingly, the scarcity of avian and mammalian predators. On smaller islands with fewer predators, birds exhibited shifts in investment from forelimbs to hindlimbs that were qualitatively similar to anatomical rearrangements observed in flightless birds. These findings suggest that island bird populations tend to evolve on a trajectory toward flightlessness, even if most remain volant. This pattern was consistent across nine families and four orders that vary in lifestyle, foraging behavior, flight style, and body size. These predictable shifts in avian morphology may reduce the physical capacity for escape via flight and diminish the potential for small-island taxa to diversify via dispersal.

  12. Evolution of the functionally conserved DCC gene in birds

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    Patthey, Cedric; Tong, Yong Guang; Tait, Christine Mary; Wilson, Sara Ivy

    2017-01-01

    Understanding the loss of conserved genes is critical for determining how phenotypic diversity is generated. Here we focus on the evolution of DCC, a gene that encodes a highly conserved neural guidance receptor. Disruption of DCC in animal models and humans results in major neurodevelopmental defects including commissural axon defects. Here we examine DCC evolution in birds, which is of particular interest as a major model system in neurodevelopmental research. We found the DCC containing locus was disrupted several times during evolution, resulting in both gene losses and faster evolution rate of salvaged genes. These data suggest that DCC had been lost independently twice during bird evolution, including in chicken and zebra finch, whereas it was preserved in many other closely related bird species, including ducks. Strikingly, we observed that commissural axon trajectory appeared similar regardless of whether DCC could be detected or not. We conclude that the DCC locus is susceptible to genomic instability leading to independent disruptions in different branches of birds and a significant influence on evolution rate. Overall, the phenomenon of loss or molecular evolution of a highly conserved gene without apparent phenotype change is of conceptual importance for understanding molecular evolution of key biological processes. PMID:28240293

  13. Novel Insights into Chromosome Evolution in Birds, Archosaurs, and Reptiles

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    Farré, Marta; Narayan, Jitendra; Slavov, Gancho T.; Damas, Joana; Auvil, Loretta; Li, Cai; Jarvis, Erich D.; Burt, David W.; Griffin, Darren K.; Larkin, Denis M.

    2016-01-01

    Homologous synteny blocks (HSBs) and evolutionary breakpoint regions (EBRs) in mammalian chromosomes are enriched for distinct DNA features, contributing to distinct phenotypes. To reveal HSB and EBR roles in avian evolution, we performed a sequence-based comparison of 21 avian and 5 outgroup species using recently sequenced genomes across the avian family tree and a newly-developed algorithm. We identified EBRs and HSBs in ancestral bird, archosaurian (bird, crocodile, and dinosaur), and reptile chromosomes. Genes involved in the regulation of gene expression and biosynthetic processes were preferably located in HSBs, including for example, avian-specific HSBs enriched for genes involved in limb development. Within birds, some lineage-specific EBRs rearranged genes were related to distinct phenotypes, such as forebrain development in parrots. Our findings provide novel evolutionary insights into genome evolution in birds, particularly on how chromosome rearrangements likely contributed to the formation of novel phenotypes. PMID:27401172

  14. Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution.

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    Mitchell, Kieren J; Llamas, Bastien; Soubrier, Julien; Rawlence, Nicolas J; Worthy, Trevor H; Wood, Jamie; Lee, Michael S Y; Cooper, Alan

    2014-05-23

    The evolution of the ratite birds has been widely attributed to vicariant speciation, driven by the Cretaceous breakup of the supercontinent Gondwana. The early isolation of Africa and Madagascar implies that the ostrich and extinct Madagascan elephant birds (Aepyornithidae) should be the oldest ratite lineages. We sequenced the mitochondrial genomes of two elephant birds and performed phylogenetic analyses, which revealed that these birds are the closest relatives of the New Zealand kiwi and are distant from the basal ratite lineage of ostriches. This unexpected result strongly contradicts continental vicariance and instead supports flighted dispersal in all major ratite lineages. We suggest that convergence toward gigantism and flightlessness was facilitated by early Tertiary expansion into the diurnal herbivory niche after the extinction of the dinosaurs.

  15. Bird embryos uncover homology and evolution of the dinosaur ankle.

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    Ossa-Fuentes, Luis; Mpodozis, Jorge; Vargas, Alexander O

    2015-11-13

    The anklebone (astragalus) of dinosaurs presents a characteristic upward projection, the 'ascending process' (ASC). The ASC is present in modern birds, but develops a separate ossification centre, and projects from the calcaneum in most species. These differences have been argued to make it non-comparable to dinosaurs. We studied ASC development in six different orders of birds using traditional techniques and spin-disc microscopy for whole-mount immunofluorescence. Unexpectedly, we found the ASC derives from the embryonic intermedium, an ancient element of the tetrapod ankle. In some birds it comes in contact with the astragalus, and, in others, with the calcaneum. The fact that the intermedium fails to fuse early with the tibiale and develops an ossification centre is unlike any other amniotes, yet resembles basal, amphibian-grade tetrapods. The ASC originated in early dinosaurs along changes to upright posture and locomotion, revealing an intriguing combination of functional innovation and reversion in its evolution.

  16. Bird embryos uncover homology and evolution of the dinosaur ankle

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    Ossa-Fuentes, Luis; Mpodozis, Jorge; Vargas, Alexander O

    2015-01-01

    The anklebone (astragalus) of dinosaurs presents a characteristic upward projection, the ‘ascending process' (ASC). The ASC is present in modern birds, but develops a separate ossification centre, and projects from the calcaneum in most species. These differences have been argued to make it non-comparable to dinosaurs. We studied ASC development in six different orders of birds using traditional techniques and spin–disc microscopy for whole-mount immunofluorescence. Unexpectedly, we found the ASC derives from the embryonic intermedium, an ancient element of the tetrapod ankle. In some birds it comes in contact with the astragalus, and, in others, with the calcaneum. The fact that the intermedium fails to fuse early with the tibiale and develops an ossification centre is unlike any other amniotes, yet resembles basal, amphibian-grade tetrapods. The ASC originated in early dinosaurs along changes to upright posture and locomotion, revealing an intriguing combination of functional innovation and reversion in its evolution. PMID:26563435

  17. Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution.

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    Galván, Ismael; Solano, Francisco

    2016-04-08

    Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models.

  18. Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution

    Directory of Open Access Journals (Sweden)

    Ismael Galván

    2016-04-01

    Full Text Available Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models.

  19. Modular color evolution facilitated by a complex nanostructure in birds.

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    Eliason, Chad M; Maia, Rafael; Shawkey, Matthew D

    2015-02-01

    The way in which a complex trait varies, and thus evolves, is critically affected by the independence, or modularity, of its subunits. How modular designs facilitate phenotypic diversification is well studied in nonornamental (e.g., cichlid jaws), but not ornamental traits. Diverse feather colors in birds are produced by light absorption by pigments and/or light scattering by nanostructures. Such structural colors are deterministically related to the nanostructures that produce them and are therefore excellent systems to study modularity and diversity of ornamental traits. Elucidating if and how these nanostructures facilitate color diversity relies on understanding how nanostructural traits covary, and how these traits map to color. Both of these remain unknown in an evolutionary context. Most dabbling ducks (Anatidae) have a conspicuous wing patch with iridescent color caused by a two-dimensional photonic crystal of small (100-200 nm) melanosomes. Here, we ask how this complex nanostructure affects modularity of color attributes. Using a combination of electron microscopy, spectrophotometry, and comparative methods, we show that nanostructural complexity causes functional decoupling and enables independent evolution of different color traits. These results demonstrate that color diversity is facilitated by how nanostructures function and may explain why some birds are more color-diverse than others.

  20. The evolution of HoxD-11 expression in the bird wing: insights from Alligator mississippiensis.

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    Alexander O Vargas

    Full Text Available BACKGROUND: Comparative morphology identifies the digits of the wing of birds as 1,2 and 3, but they develop at embryological positions that become digits 2, 3 and 4 in other amniotes. A hypothesis to explain this is that a homeotic frame shift of digital identity occurred in the evolution of the bird wing, such that digits 1,2 and 3 are developing from embryological positions 2, 3 and 4. Digit 1 of the mouse is the only digit that shows no late expression of HoxD-11. This is also true for the anterior digit of the bird wing, suggesting this digit is actually a digit 1. If this is the case, we can expect closer relatives of birds to show no HoxD-11 expression only in digit 1. To test this prediction we investigate HoxD-11 expression in crocodilians, the closest living relatives of birds. METHODOLOGY/PRINCIPAL FINDINGS: Using degenerate primers we cloned a 606 nucleotide fragment of exon 1 of the alligator HoxD-11 gene and used it for whole-mount in-situ detection in alligator embryos. We found that in the pentadactyl forelimbs of alligator, as in the mouse, late expression of HoxD-11 is absent only in digit 1. CONCLUSIONS/SIGNIFICANCE: The ancestral condition for amniotes is that late-phase HoxD-11 expression is absent only in digit 1. The biphalangeal morphology and lack of HoxD-11 expression of the anterior digit of the wing is like digit 1 of alligator and mouse, but its embryological position as digit 2 is derived. HoxD-11 expression in alligator is consistent with the hypothesis that both digit morphology as well as HoxD-11 expression are shifted towards posterior in the bird wing.

  1. The Evolution of HoxD-11 Expression in the Bird Wing: Insights from Alligator mississippiensis

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    Vargas, Alexander O.; Kohlsdorf, Tiana; Fallon, John F.; VandenBrooks, John; Wagner, Günter P.

    2008-01-01

    Background Comparative morphology identifies the digits of the wing of birds as 1,2 and 3, but they develop at embryological positions that become digits 2, 3 and 4 in other amniotes. A hypothesis to explain this is that a homeotic frame shift of digital identity occurred in the evolution of the bird wing, such that digits 1,2 and 3 are developing from embryological positions 2, 3 and 4. Digit 1 of the mouse is the only digit that shows no late expression of HoxD-11. This is also true for the anterior digit of the bird wing, suggesting this digit is actually a digit 1. If this is the case, we can expect closer relatives of birds to show no HoxD-11 expression only in digit 1. To test this prediction we investigate HoxD-11 expression in crocodilians, the closest living relatives of birds. Methodology/Principal Findings Using degenerate primers we cloned a 606 nucleotide fragment of exon 1 of the alligator HoxD-11 gene and used it for whole-mount in-situ detection in alligator embryos. We found that in the pentadactyl forelimbs of alligator, as in the mouse, late expression of HoxD-11 is absent only in digit 1. Conclusions/Significance The ancestral condition for amniotes is that late-phase HoxD-11 expression is absent only in digit 1. The biphalangeal morphology and lack of HoxD-11 expression of the anterior digit of the wing is like digit 1 of alligator and mouse, but its embryological position as digit 2 is derived. HoxD-11 expression in alligator is consistent with the hypothesis that both digit morphology as well as HoxD-11 expression are shifted towards posterior in the bird wing. PMID:18833328

  2. Testing hypotheses associated with bird responses to wildfire.

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    Lindenmayer, David B; Wood, Jeff T; Cunningham, Ross B; MacGregor, Christopher; Crane, Mason; Michael, Damian; Montague-Drake, Rebecca; Brown, Darren; Muntz, Rachel; Gill, A Malcolm

    2008-12-01

    Disturbance is a key ecological process influencing the distribution and abundance of many elements of the earth's biota. Predicting the response of biota to disturbance is therefore important, but it nevertheless remains difficult to make accurate forecasts of response. We tested predictions from disturbance-related theories and concepts in 10 vegetation types at Booderee National Park (southeastern Australia) using a retrospective study of bird responses to fire history (over 35 years) on 110 sites and a prospective study following a single wildfire event in 2003 at 59 of these sites. Our data did not support predictions from the intermediate-disturbance hypothesis; observed bird species richness at a site was significantly (F(1,99) = 6.30, P = 0.014) negatively related to the number of fires since 1972 and was 8.7% lower (95% CI, 1.8-15.1%) for each additional fire. In contrast to fire history effects, we found that after the 2003 fire, the vast majority of individual species and the bird assemblage per se in most vegetation types recovered within two years. Thus, recovery after a single fire did not reflect long-term effects of multiple fires on overall bird species richness at a site. We postulated that the recovery of bird species richness and bird assemblage composition after the 2003 fire would be fastest in structurally simple vegetation types and slowest in structurally complex vegetation, but observed the opposite. Although observed bird species richness in vertically heterogeneous forest and woodland had returned to prefire levels by 2006, bird species richness in structurally simple vegetation types (e.g., sedgeland) had not. Postfire vegetation regeneration, together with a paucity of early-successional specialists, would explain the speed of recovery of the bird assemblage and why it changed relatively little during our investigation.

  3. Widespread correlations between climatic niche evolution and species diversification in birds.

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    Cooney, Christopher R; Seddon, Nathalie; Tobias, Joseph A

    2016-07-01

    The adaptability of species' climatic niches can influence the dynamics of colonization and gene flow across climatic gradients, potentially increasing the likelihood of speciation or reducing extinction in the face of environmental change. However, previous comparative studies have tested these ideas using geographically, taxonomically and ecologically restricted samples, yielding mixed results, and thus the processes linking climatic niche evolution with diversification remain poorly understood. Focusing on birds, the largest and most widespread class of terrestrial vertebrates, we test whether variation in species diversification among clades is correlated with rates of climatic niche evolution and the extent to which these patterns are modified by underlying gradients in biogeography and species' ecology. We quantified climatic niches, latitudinal distribution and ecological traits for 7657 (˜75%) bird species based on geographical range polygons and then used Bayesian phylogenetic analyses to test whether niche evolution was related to species richness and rates of diversification across genus- and family-level clades. We found that the rate of climatic niche evolution has a positive linear relationship with both species richness and diversification rate at two different taxonomic levels (genus and family). Furthermore, this positive association between labile climatic niches and diversification was detected regardless of variation in clade latitude or key ecological traits. Our findings suggest either that rapid adaptation to unoccupied areas of climatic niche space promotes avian diversification, or that diversification promotes adaptation. Either way, we propose that climatic niche evolution is a fundamental process regulating the link between climate and biodiversity at global scales, irrespective of the geographical and ecological context of speciation and extinction.

  4. Rates of dinosaur limb evolution provide evidence for exceptional radiation in Mesozoic birds.

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    Benson, Roger B J; Choiniere, Jonah N

    2013-10-07

    Birds are the most diverse living tetrapod group and are a model of large-scale adaptive radiation. Neontological studies suggest a radiation within the avian crown group, long after the origin of flight. However, deep time patterns of bird evolution remain obscure because only limited fossil data have been considered. We analyse cladogenesis and limb evolution on the entire tree of Mesozoic theropods, documenting the dinosaur-bird transition and immediate origins of powered flight. Mesozoic birds inherited constraints on forelimb evolution from non-flying ancestors, and species diversification rates did not accelerate in the earliest flying taxa. However, Early Cretaceous short-tailed birds exhibit both phenotypic release of the hindlimb and increased diversification rates, unparalleled in magnitude at any other time in the first 155 Myr of theropod evolution. Thus, a Cretaceous adaptive radiation of stem-group birds was enabled by restructuring of the terrestrial locomotor module, which represents a key innovation. Our results suggest two phases of radiation in Avialae: with the Cretaceous diversification overwritten by extinctions of stem-group birds at the Cretaceous-Palaeogene boundary, and subsequent diversification of the crown group. Our findings illustrate the importance of fossil data for understanding the macroevolutionary processes generating modern biodiversity.

  5. Dinosaur evolution. Sustained miniaturization and anatomical innovation in the dinosaurian ancestors of birds.

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    Lee, Michael S Y; Cau, Andrea; Naish, Darren; Dyke, Gareth J

    2014-08-01

    Recent discoveries have highlighted the dramatic evolutionary transformation of massive, ground-dwelling theropod dinosaurs into light, volant birds. Here, we apply Bayesian approaches (originally developed for inferring geographic spread and rates of molecular evolution in viruses) in a different context: to infer size changes and rates of anatomical innovation (across up to 1549 skeletal characters) in fossils. These approaches identify two drivers underlying the dinosaur-bird transition. The theropod lineage directly ancestral to birds undergoes sustained miniaturization across 50 million years and at least 12 consecutive branches (internodes) and evolves skeletal adaptations four times faster than other dinosaurs. The distinct, prolonged phase of miniaturization along the bird stem would have facilitated the evolution of many novelties associated with small body size, such as reorientation of body mass, increased aerial ability, and paedomorphic skulls with reduced snouts but enlarged eyes and brains.

  6. Fluctuating environments, sexual selection and the evolution of flexible mate choice in birds.

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    Botero, Carlos A; Rubenstein, Dustin R

    2012-01-01

    Environmentally-induced fluctuation in the form and strength of natural selection can drive the evolution of morphology, physiology, and behavior. Here we test the idea that fluctuating climatic conditions may also influence the process of sexual selection by inducing unexpected reversals in the relative quality or sexual attractiveness of potential breeding partners. Although this phenomenon, known as 'ecological cross-over', has been documented in a variety of species, it remains unclear the extent to which it has driven the evolution of major interspecific differences in reproductive behavior. We show that after controlling for potentially influential life history and demographic variables, there are significant positive associations between the variability and predictability of annual climatic cycles and the prevalence of infidelity and divorce within populations of a taxonomically diverse array of socially monogamous birds. Our results are consistent with the hypothesis that environmental factors have shaped the evolution of reproductive flexibility and suggest that in the absence of severe time constraints, secondary mate choice behaviors can help prevent, correct, or minimize the negative consequences of ecological cross-overs. Our findings also illustrate how a basic evolutionary process like sexual selection is susceptible to the increasing variability and unpredictability of climatic conditions that is resulting from climate change.

  7. A new time tree reveals Earth history’s imprint on the evolution of modern birds

    Science.gov (United States)

    Claramunt, Santiago; Cracraft, Joel

    2015-01-01

    Determining the timing of diversification of modern birds has been difficult. We combined DNA sequences of clock-like genes for most avian families with 130 fossil birds to generate a new time tree for Neornithes and investigated their biogeographic and diversification dynamics. We found that the most recent common ancestor of modern birds inhabited South America around 95 million years ago, but it was not until the Cretaceous-Paleogene transition (66 million years ago) that Neornithes began to diversify rapidly around the world. Birds used two main dispersion routes: reaching the Old World through North America, and reaching Australia and Zealandia through Antarctica. Net diversification rates increased during periods of global cooling, suggesting that fragmentation of tropical biomes stimulated speciation. Thus, we found pervasive evidence that avian evolution has been influenced by plate tectonics and environmental change, two basic features of Earth’s dynamics. PMID:26824065

  8. A new time tree reveals Earth history's imprint on the evolution of modern birds.

    Science.gov (United States)

    Claramunt, Santiago; Cracraft, Joel

    2015-12-01

    Determining the timing of diversification of modern birds has been difficult. We combined DNA sequences of clock-like genes for most avian families with 130 fossil birds to generate a new time tree for Neornithes and investigated their biogeographic and diversification dynamics. We found that the most recent common ancestor of modern birds inhabited South America around 95 million years ago, but it was not until the Cretaceous-Paleogene transition (66 million years ago) that Neornithes began to diversify rapidly around the world. Birds used two main dispersion routes: reaching the Old World through North America, and reaching Australia and Zealandia through Antarctica. Net diversification rates increased during periods of global cooling, suggesting that fragmentation of tropical biomes stimulated speciation. Thus, we found pervasive evidence that avian evolution has been influenced by plate tectonics and environmental change, two basic features of Earth's dynamics.

  9. Gradual assembly of avian body plan culminated in rapid rates of evolution across the dinosaur-bird transition.

    Science.gov (United States)

    Brusatte, Stephen L; Lloyd, Graeme T; Wang, Steve C; Norell, Mark A

    2014-10-20

    The evolution of birds from theropod dinosaurs was one of the great evolutionary transitions in the history of life. The macroevolutionary tempo and mode of this transition is poorly studied, which is surprising because it may offer key insight into major questions in evolutionary biology, particularly whether the origins of evolutionary novelties or new ecological opportunities are associated with unusually elevated "bursts" of evolution. We present a comprehensive phylogeny placing birds within the context of theropod evolution and quantify rates of morphological evolution and changes in overall morphological disparity across the dinosaur-bird transition. Birds evolved significantly faster than other theropods, but they are indistinguishable from their closest relatives in morphospace. Our results demonstrate that the rise of birds was a complex process: birds are a continuum of millions of years of theropod evolution, and there was no great jump between nonbirds and birds in morphospace, but once the avian body plan was gradually assembled, birds experienced an early burst of rapid anatomical evolution. This suggests that high rates of morphological evolution after the development of a novel body plan may be a common feature of macroevolution, as first hypothesized by G.G. Simpson more than 60 years ago.

  10. The evolution of hindlimb tendons and muscles on the line to crown-group birds.

    Science.gov (United States)

    Hutchinson, John R

    2002-12-01

    The anatomy and functions of muscle-tendon complexes and their bony attachments in birds and their outgroups show how the major pelvic limb muscle groups evolved. Fossils reveal that most changes evolved after the divergence of archosaurs in the Triassic, particularly in the dinosaurian precursors to birds. Three-dimensional limb control became concentrated at the hip joint; more distal joints and muscles were restricted to flexion or extension early in dinosaur evolution. Hip extensors expanded even though the primary femoral retractor M. caudofemoralis longus was reduced. Hip flexors and two-joint "hamstring" muscles were simplified to a few large heads. Knee extensors increased their sizes and moment arms early in bipedal dinosaurs, but the patella and cranial cnemial crest evolved later in birds. Lower limb muscles expanded as ossifications such as the hypotarsus increased their moment arms. The ossification of lower limb tendons, particularly in extensors, is a recent novelty of birds. Muscles and tendons that develop large forces, stresses, and moments to stabilize or move the limbs became increasingly prominent on the line to birds. Locomotion evolved in a stepwise pattern that only recently produced the derived limb control mechanisms of crown-group birds, such as the strongly flexed hip and knee joints.

  11. Assessing arboreal adaptations of bird antecedents: testing the ecological setting of the origin of the avian flight stroke.

    Directory of Open Access Journals (Sweden)

    T Alexander Dececchi

    Full Text Available The origin of avian flight is a classic macroevolutionary transition with research spanning over a century. Two competing models explaining this locomotory transition have been discussed for decades: ground up versus trees down. Although it is impossible to directly test either of these theories, it is possible to test one of the requirements for the trees-down model, that of an arboreal paravian. We test for arboreality in non-avian theropods and early birds with comparisons to extant avian, mammalian, and reptilian scansors and climbers using a comprehensive set of morphological characters. Non-avian theropods, including the small, feathered deinonychosaurs, and Archaeopteryx, consistently and significantly cluster with fully terrestrial extant mammals and ground-based birds, such as ratites. Basal birds, more advanced than Archaeopteryx, cluster with extant perching ground-foraging birds. Evolutionary trends immediately prior to the origin of birds indicate skeletal adaptations opposite that expected for arboreal climbers. Results reject an arboreal capacity for the avian stem lineage, thus lending no support for the trees-down model. Support for a fully terrestrial ecology and origin of the avian flight stroke has broad implications for the origin of powered flight for this clade. A terrestrial origin for the avian flight stroke challenges the need for an intermediate gliding phase, presents the best resolved series of the evolution of vertebrate powered flight, and may differ fundamentally from the origin of bat and pterosaur flight, whose antecedents have been postulated to have been arboreal and gliding.

  12. Avian sleep homeostasis: convergent evolution of complex brains, cognition and sleep functions in mammals and birds.

    Science.gov (United States)

    Rattenborg, Niels C; Martinez-Gonzalez, Dolores; Lesku, John A

    2009-03-01

    Birds are the only taxonomic group other than mammals that exhibit high-amplitude slow-waves in the electroencephalogram (EEG) during sleep. This defining feature of slow-wave sleep (SWS) apparently evolved independently in mammals and birds, as reptiles do not exhibit similar EEG activity during sleep. In mammals, the level of slow-wave activity (SWA) (low-frequency spectral power density) during SWS increases and decreases as a function of prior time spent awake and asleep, respectively, and therefore reflects homeostatically regulated sleep processes potentially tied to the function of SWS. Although birds also exhibit SWS, previous sleep deprivation studies in birds did not detect a compensatory increase in SWS-related SWA during recovery, as observed in similarly sleep-deprived mammals. This suggested that, unlike mammalian SWS, avian SWS is not homeostatically regulated, and therefore might serve a different function. However, we recently demonstrated that SWA during SWS increases in pigeons following short-term sleep deprivation. Herein we summarize research on avian sleep homeostasis, and cast our evidence for this phenomenon within the context of theories for the function of SWS in mammals. We propose that the convergent evolution of homeostatically regulated SWS in mammals and birds was directly linked to the convergent evolution of large, heavily interconnected brains capable of performing complex cognitive processes in each group. Specifically, as has been proposed for mammals, the interconnectivity that forms the basis of complex cognition in birds may also instantiate slow, synchronous network oscillations during SWS that in turn maintain interconnectivity and cognition at an optimal level.

  13. Deadly hairs, lethal feathers--convergent evolution of poisonous integument in mammals and birds.

    Science.gov (United States)

    Plikus, Maksim V; Astrowski, Aliaksandr A

    2014-07-01

    Hairs and feathers are textbook examples of the convergent evolution of the follicular appendage structure between mammals and birds. While broadly recognized for their convergent thermoregulatory, camouflage and sexual display functions, hairs and feathers are rarely thought of as deadly defence tools. Several recent studies, however, show that in some species of mammals and birds, the integument can, in fact, be a de facto lethal weapon. One mammalian example is provided by African crested rats, which seek for and chew on the bark of plants containing the highly potent toxin, ouabain. These rats then coat their fur with ouabain-containing saliva. For efficient toxin retention, the rodents have evolved highly specialized fenestrated and mostly hollow hair shafts that soak up liquids, which essentially function as wicks. On the avian side of the vertebrate integumental variety spectrum, several species of birds of New Guinea have evolved resistance to highly potent batrachotoxins, which they acquire from their insect diet. While the mechanism of bird toxicity remains obscure, in a recently published issue of the journal, Dumbacher and Menon explore the intriguing idea that to achieve efficient storage of batrachotoxins in their skin, some birds exploit the basic permeability barrier function of their epidermis. Batrachotoxins become preferentially sequestered in their epidermis and are then transferred to feathers, likely through the exploitation of specialized avian lipid-storing multigranular body organelles. Here, we discuss wider implications of this intriguing concept.

  14. Evolution of Embryonic Developmental Period in the Marine Bird Families Alcidae and Spheniscidae: Roles for Nutrition and Predation?

    OpenAIRE

    Vos Rutger A; Gorman Kristen B; Hipfner J Mark; Joy Jeffrey B

    2010-01-01

    Abstract Background Nutrition and predation have been considered two primary agents of selection important in the evolution of avian life history traits. The relative importance of these natural selective forces in the evolution of avian embryonic developmental period (EDP) remain poorly resolved, perhaps in part because research has tended to focus on a single, high taxonomic-level group of birds: Order Passeriformes. The marine bird families Alcidae (auks) and Spheniscidae (penguins) exhibi...

  15. Nonapeptides and the Evolution of Social Group Sizes in Birds

    Directory of Open Access Journals (Sweden)

    James L. Goodson

    2011-03-01

    Full Text Available Species-typical patterns of grouping have profound impacts on many aspects of physiology and behavior. However, prior to our recent studies in estrildid finches, neural mechanisms that titrate species-typical group size preferences, independent of other aspects of social organization (e.g., mating system and parental care, have been wholly unexplored, likely because species-typical group size is typically confounded with other aspects of behavior and biology. An additional complication is that components of social organization are evolutionarily labile and prone to repeated divergence and convergence. Hence, we cannot assume that convergence in social structure has been produced by convergent modifications to the same neural characters, and thus any comparative approach to grouping must include not only species that differ in their species-typical group sizes, but also species that exhibit convergent evolution in this aspect of social organization. Using five estrildid finch species that differ selectively in grouping (all biparental and monogamous we have demonstrated that neural motivational systems evolve in predictable ways in relation to species-typical group sizes, including convergence in two highly gregarious species and convergence in two relatively asocial, territorial species. These systems include nonapeptide (vasotocin and mesotocin circuits that encode the valence of social stimuli (positive-negative, titrate group-size preferences, and modulate anxiety-like behaviors. Nonapeptide systems exhibit functional and anatomical properties that are biased towards gregarious species, and experimental reductions of nonapeptide signaling by receptor antagonism and antisense oligonucleotides significantly decrease preferred group sizes in the gregarious zebra finch. Combined, these findings suggest that selection on species-typical group size may reliably target the same neural motivation systems when a given social structure evolves

  16. Axial compression physical testing of traditional and bird beak SHS T-joints

    Institute of Scientific and Technical Information of China (English)

    陈誉; 王江

    2015-01-01

    The static tests of nine traditional and bird beak square hollow structure (SHS) T-joints with differentβ values and connection types under axial compression at brace end were carried out. Experimental test schemes, failure modes of specimens, jack load−vertical displacement curves, jack load−deformation of chord and strain intensity distribution curves of joints were presented. The effects ofβ and connection types on axial compression property of joints were studied. The results show that the ultimate axial compression capacity of common bird beak SHS T-joints and diamond bird beak SHS T-joints is larger than that of traditional SHS T-joint specimens with big values ofβ. The ultimate axial compression capacity of diamond bird beak SHS T-joints is larger than that of common bird beak SHS T-joints. Asβ increases, the increase of the ultimate axial compression capacity of diamond bird beak SHS T-joints over that of common bird beak joints grows. The ultimate axial compression capacity and the initial axial stiffness of all kinds of joints increase asβincreases, and the initial axial stiffness of the diamond bird beak SHS T-joints is the largest. The ductilities of common bird beak and diamond bird beak SHS T-joints increase asβ increases, but the ductility of the traditional SHS T-joints decreases asβ increases.

  17. Testing bird response to roads on a rural environment: A case study from Central Italy

    Science.gov (United States)

    Morelli, Federico; Jerzak, Leszek; Pruscini, Fabio; Santolini, Riccardo; Benedetti, Yanina; Tryjanowski, Piotr

    2015-11-01

    The construction of roads is currently well spread in many parts of our world and impacts strongly on wildlife distribution. Some bird species avoid, while other prefer to be in the vicinity of these human structures. However, studies on roads effects on birds, in terms of strength or direction of these effects, are scarce. Therefore, in a study carried out in Central Italy we tested the responses of different bird species to roads at a local spatial scale, using generalized linear models (GLM). Analysis were conducted on a large dataset (more than 1400 sampled sites, mainly on rural environments). Both positive and negative effects of roads on birds were found for bird species of close or semi-close environments, while the negative effects of roads were negligible for bird species of open and semi-open environments. This fact suggest that roads can be a source of "functional heterogeneity" on semi-open environments, providing marginal habitats, hedgerows and residual vegetation typical of roadsides, offering breeding and feeding habitat for some bird species. The proposed methodology provide a useful explorative tool, in order to develop conservation policies to preserve the biodiversity, mainly in rural landscapes. The outputs of GLM can be used as inputs in ecological planning: direction and strength of the effects of roads on bird species are adequate to estimate the response of bird community, up front to the presence of new structures, or identifying which of them should be mitigated to reduce negative effects on the biodiversity.

  18. Contact and hybrid zone hotspots and evolution of birds in the Middle East

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Middle East is an important contact zone for a considerable number of bird taxa from the western and eastern Palearctic and from the great Saharo-Sindian jesert belt. Using WORLDMAP software, we analyzed the geographical distribution of secondary contact zones for parapatric species pairs of birds in the Middle East. We identified 56 species (29 species pairs) that make contact in the Middle East. The species pairs belong to three orders, i.e. Falconiformes, Piciformes, and Passeriformes. Almost half (46%) of these species pairs hybridize in their contact zones. Although contact zones occur over a large part of northern Middle East, spatially they were not evenly distributed. Contact zone richness was highest in the mountain ranges south of the Caspian Sea and the Caucasus. The hottest hotspots, where up to nine bird species pairs occur sympatrically, are situated in north-eastern Iran and Azerbaijan. We discuss the relevance of these hotspots for improving our understanding of the biogeography and evolution of the avifauna in the Middle East.

  19. Jinfengopteryx Compared to Archaeopteryx, with Comments on the Mosaic Evolution of Long-tailed Avialan Birds

    Institute of Scientific and Technical Information of China (English)

    JI Shu'an; JI Qiang

    2007-01-01

    Jinfengopteryx is a newly uncovered Archaeopteryx-like avialan bird outside Germany, which was found from the Jehol Biota of northern Hebei in northeastern China. It shares many characters only with Archaeopteryx by the possession of three fenestrae in the antorbital cavity, 23 caudal vertebrae and long tail feathers attached to all the caudal vertebrae. But the former differs from the latter in the relatively short and high preorbital region of skull, more and closely packed teeth, much shorter forelimb compared to hindlimb. Such differences indicate Jinfengopteryx is even slightly more primitive than Archaeopteryx, although both birds can be placed at the root position of the avialan tree based on cladistic analysis. Shenzhouraptor is suggested to be slightly more advanced than Jinfengopteryx + Archaeopteryx, supported by some derived features in teeth, shoulder girdles and forelimbs such as the reduction of tooth number, dorsolaterally directed glenoid facet, very long forelimb and comparatively short manus. Meanwhile, the tail of Shenzhouraptor shows more primitive characters than those of Jinfengopteryx and Archaeopteryx, e.g., the strikingly longer tail composed of more caudal vertebrae and the long tail feathers attached only to distal caudal segments. The mixed primitive and advanced characters reveal the evident mosaic evolution among long-tailed avialan birds.

  20. Domestication and the mitochondrial genome: comparing patterns and rates of molecular evolution in domesticated mammals and birds and their wild relatives.

    Science.gov (United States)

    Moray, Camile; Lanfear, Robert; Bromham, Lindell

    2014-01-01

    Studies of domesticated animals have led to the suggestion that domestication could have significant effects on patterns of molecular evolution. In particular, analyses of mitochondrial genome sequences from domestic dogs and yaks have yielded higher ratios of non-synonymous to synonymous substitutions in the domesticated lineages than in their wild relatives. These results are important because they imply that changes to selection or population size operating over a short timescale can cause significant changes to the patterns of mitochondrial molecular evolution. In this study, our aim is to test whether the impact on mitochondrial genome evolution is a general feature of domestication or whether it is specific to particular examples. We test whether domesticated mammals and birds have consistently different patterns of molecular evolution than their wild relatives for 16 phylogenetically independent comparisons of mitochondrial genome sequences. We find no consistent difference in branch lengths or dN/dS between domesticated and wild lineages. We also find no evidence that our failure to detect a consistent pattern is due to the short timescales involved or low genetic distance between domesticated lineages and their wild relatives. However, removing comparisons where the wild relative may also have undergone a bottleneck does reveal a pattern consistent with reduced effective population size in domesticated lineages. Our results suggest that, although some domesticated lineages may have undergone changes to selective regime or effective population size that could have affected mitochondrial evolution, it is not possible to generalize these patterns over all domesticated mammals and birds.

  1. Bees, birds and yellow flowers: pollinator-dependent convergent evolution of UV patterns.

    Science.gov (United States)

    Papiorek, S; Junker, R R; Alves-Dos-Santos, I; Melo, G A R; Amaral-Neto, L P; Sazima, M; Wolowski, M; Freitas, L; Lunau, K

    2016-01-01

    Colour is one of the most obvious advertisements of flowers, and occurs in a huge diversity among the angiosperms. Flower colour is responsible for attraction from a distance, whereas contrasting colour patterns within flowers aid orientation of flower visitors after approaching the flowers. Due to the striking differences in colour vision systems and neural processing across animal taxa, flower colours evoke specific behavioural responses by different flower visitors. We tested whether and how yellow flowers differ in their spectral reflectance depending on the main pollinator. We focused on bees and birds and examined whether the presence or absence of the widespread UV reflectance pattern of yellow flowers predicts the main pollinator. Most bee-pollinated flowers displayed a pattern with UV-absorbing centres and UV-reflecting peripheries, whereas the majority of bird-pollinated flowers are entirely UV- absorbing. In choice experiments we found that bees did not show consistent preferences for any colour or pattern types. However, all tested bee species made their first antennal contact preferably at the UV-absorbing area of the artificial flower, irrespective of its spatial position within the flower. The appearance of UV patterns within flowers is the main difference in spectral reflectance between yellow bee- and bird-pollinated flowers, and affects the foraging behaviour of flower visitors. The results support the hypothesis that flower colours and the visual capabilities of their efficient pollinators are adapted to each other.

  2. Does bird species diversity vary among forest types? A local-scale test in Southern Chile

    Science.gov (United States)

    Fontúrbel, Francisco E.; Jiménez, Jaime E.

    2014-10-01

    Birds are the most diverse vertebrate group in Chile, characterized by low species turnover at the country-size scale (high alpha but low beta diversities), resembling an island biota. We tested whether this low differentiation is valid at a local scale, among six forest habitat types. We detected 25 bird species; avifauna composition was significantly different among habitat types, with five species accounting for 60 % of the dissimilarity. We found a higher level of bird assemblage differentiation across habitats at the local scale than has been found at the country-size scale. Such differentiation might be attributed to structural differences among habitats.

  3. Aeroelastic flutter of feathers, flight and the evolution of non-vocal communication in birds.

    Science.gov (United States)

    Clark, Christopher J; Prum, Richard O

    2015-11-01

    Tonal, non-vocal sounds are widespread in both ordinary bird flight and communication displays. We hypothesized these sounds are attributable to an aerodynamic mechanism intrinsic to flight feathers: aeroelastic flutter. Individual wing and tail feathers from 35 taxa (from 13 families) that produce tonal flight sounds were tested in a wind tunnel. In the wind tunnel, all of these feathers could flutter and generate tonal sound, suggesting that the capacity to flutter is intrinsic to flight feathers. This result implies that the aerodynamic mechanism of aeroelastic flutter is potentially widespread in flight of birds. However, the sounds these feathers produced in the wind tunnel replicated the actual flight sounds of only 15 of the 35 taxa. Of the 20 negative results, we hypothesize that 10 are false negatives, as the acoustic form of the flight sound suggests flutter is a likely acoustic mechanism. For the 10 other taxa, we propose our negative wind tunnel results are correct, and these species do not make sounds via flutter. These sounds appear to constitute one or more mechanism(s) we call 'wing whirring', the physical acoustics of which remain unknown. Our results document that the production of non-vocal communication sounds by aeroelastic flutter of flight feathers is widespread in birds. Across all birds, most evolutionary origins of wing- and tail-generated communication sounds are attributable to three mechanisms: flutter, percussion and wing whirring. Other mechanisms of sound production, such as turbulence-induced whooshes, have evolved into communication sounds only rarely, despite their intrinsic ubiquity in ordinary flight.

  4. Molecular development of fibular reduction in birds and its evolution from dinosaurs.

    Science.gov (United States)

    Botelho, João Francisco; Smith-Paredes, Daniel; Soto-Acuña, Sergio; O'Connor, Jingmai; Palma, Verónica; Vargas, Alexander O

    2016-03-01

    Birds have a distally reduced, splinter-like fibula that is shorter than the tibia. In embryonic development, both skeletal elements start out with similar lengths. We examined molecular markers of cartilage differentiation in chicken embryos. We found that the distal end of the fibula expresses Indian hedgehog (IHH), undergoing terminal cartilage differentiation, and almost no Parathyroid-related protein (PTHrP), which is required to develop a proliferative growth plate (epiphysis). Reduction of the distal fibula may be influenced earlier by its close contact with the nearby fibulare, which strongly expresses PTHrP. The epiphysis-like fibulare however then separates from the fibula, which fails to maintain a distal growth plate, and fibular reduction ensues. Experimental downregulation of IHH signaling at a postmorphogenetic stage led to a tibia and fibula of equal length: The fibula is longer than in controls and fused to the fibulare, whereas the tibia is shorter and bent. We propose that the presence of a distal fibular epiphysis may constrain greater growth in the tibia. Accordingly, many Mesozoic birds show a fibula that has lost its distal epiphysis, but remains almost as long as the tibia, suggesting that loss of the fibulare preceded and allowed subsequent evolution of great fibulo-tibial disparity.

  5. Cranial shape evolution in adaptive radiations of birds: comparative morphometrics of Darwin's finches and Hawaiian honeycreepers

    Science.gov (United States)

    Tokita, Masayoshi; Yano, Wataru; James, Helen F.

    2017-01-01

    Adaptive radiation is the rapid evolution of morphologically and ecologically diverse species from a single ancestor. The two classic examples of adaptive radiation are Darwin's finches and the Hawaiian honeycreepers, which evolved remarkable levels of adaptive cranial morphological variation. To gain new insights into the nature of their diversification, we performed comparative three-dimensional geometric morphometric analyses based on X-ray microcomputed tomography (µCT) scanning of dried cranial skeletons. We show that cranial shapes in both Hawaiian honeycreepers and Coerebinae (Darwin's finches and their close relatives) are much more diverse than in their respective outgroups, but Hawaiian honeycreepers as a group display the highest diversity and disparity of all other bird groups studied. We also report a significant contribution of allometry to skull shape variation, and distinct patterns of evolutionary change in skull morphology in the two lineages of songbirds that underwent adaptive radiation on oceanic islands. These findings help to better understand the nature of adaptive radiations in general and provide a foundation for future investigations on the developmental and molecular mechanisms underlying diversification of these morphologically distinguished groups of birds. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’. PMID:27994122

  6. [Evolution of urine test paper].

    Science.gov (United States)

    Ohno, Akemi

    2014-07-01

    Qualitative urinalysis with test strips is utilized as a screening test. Test strip use has been incorporated in the diagnostic criteria of a variety of clinical practice guidelines. The strips can measure many parameters and have the advantage of being able to rapidly provide results at a low cost. I hope that the standardization of parameters on test strip use will progress further, and that new urine biomarkers will be included.

  7. Carotenoid-dependent signals and the evolution of plasma carotenoid levels in birds.

    Science.gov (United States)

    Simons, Mirre J P; Maia, Rafael; Leenknegt, Bas; Verhulst, Simon

    2014-12-01

    Sexual selection has resulted in a wide array of ornaments used in mate choice, and such indicator traits signal quality honestly when they bear costs, precluding cheating. Carotenoid-dependent coloration has attracted considerable attention in this context, because investing carotenoids in coloration has to be traded off against its physiological functions; carotenoids are antioxidants and increase immunocompetence. This trade-off is hypothesized to underlie the honesty of carotenoid-dependent coloration, signaling the "handicap" of allocating carotenoids away from somatic maintenance toward sexual display. Utilizing recent advances in modeling adaptive evolution, we used a comparative approach to investigate the evolution of plasma carotenoid levels using a species-level phylogeny of 178 bird species. We find that the evolutionary optimum for carotenoid levels is higher in lineages that evolved carotenoid-dependent coloration, with strong attraction toward this optimum. Hence, carotenoids do not appear to be limiting, given that higher carotenoid levels readily evolve in response to the evolution of carotenoid-dependent coloration. These findings challenge the assumption that carotenoids are a scarce resource and thus also challenge the hypothesis that physiological resource value of carotenoids underlies honesty of carotenoid-dependent traits. Therefore, the comparative evidence suggests that other factors, such as the acquisition and incorporation of carotenoids, are involved in maintaining signal honesty.

  8. Independent evolution of transcriptional inactivation on sex chromosomes in birds and mammals.

    Directory of Open Access Journals (Sweden)

    Alexandra M Livernois

    Full Text Available X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination. We used RNA-fluorescent in situ hybridization (RNA-FISH to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes.

  9. Independent evolution of transcriptional inactivation on sex chromosomes in birds and mammals.

    Science.gov (United States)

    Livernois, Alexandra M; Waters, Shafagh A; Deakin, Janine E; Marshall Graves, Jennifer A; Waters, Paul D

    2013-01-01

    X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination). We used RNA-fluorescent in situ hybridization (RNA-FISH) to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains) on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial) silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes.

  10. The evolution, maintenance and adaptive function of genetic colour polymorphism in birds.

    Science.gov (United States)

    Roulin, Alexandre

    2004-11-01

    The hypothesis that ornaments can honestly signal quality only if their expression is condition-dependent has dominated the study of the evolution and function of colour traits. Much less interest has been devoted to the adaptive function of colour traits for which the expression is not, or is to a low extent, sensitive to body condition and the environment in which individuals live. The aim of the present paper is to review the current theoretical and empirical knowledge of the evolution, maintenance and adaptive function of colour plumage traits for which the expression is mainly under genetic control. The finding that in many bird species the inheritance of colour morphs follows the laws of Mendel indicates that genetic colour polymorphism is frequent. Polymorphism may have evolved or be maintained because each colour morph facilitates the exploitation of alternative ecological niches as suggested by the observation that individuals are not randomly distributed among habitats with respect to coloration. Consistent with the hypothesis that different colour morphs are linked to alternative strategies is the finding that in a majority of species polymorphism is associated with reproductive parameters, and behavioural, life-history and physiological traits. Experimental studies showed that such covariations can have a genetic basis. These observations suggest that colour polymorphism has an adaptive function. Aviary and field experiments demonstrated that colour polymorphism is used as a criterion in mate-choice decisions and dominance interactions confirming the claim that conspecifics assess each other's colour morphs. The factors favouring the evolution and maintenance of genetic variation in coloration are reviewed, but empirical data are virtually lacking to assess their importance. Although current theory predicts that only condition-dependent traits can signal quality, the present review shows that genetically inherited morphs can reveal the same qualities

  11. Niche evolution and diversification in a Neotropical radiation of birds (Aves: Furnariidae).

    Science.gov (United States)

    Seeholzer, Glenn F; Claramunt, Santiago; Brumfield, Robb T

    2017-03-01

    Rapid diversification may be caused by ecological adaptive radiation via niche divergence. In this model, speciation is coupled with niche divergence and lineage diversification is predicted to be correlated with rates of niche evolution. Studies of the role of niche evolution in diversification have generally focused on ecomorphological diversification but climatic-niche evolution may also be important. We tested these alternatives using a phylogeny of 298 species of ovenbirds (Aves: Furnariidae). We found that within Furnariidae, variation in species richness and diversification rates of subclades were best predicted by rate of climatic-niche evolution than ecomorphological evolution. Although both are clearly important, univariate regression and multivariate model averaging more consistently supported the climatic-niche as the best predictor of lineage diversification. Our study adds to the growing body of evidence, suggesting that climatic-niche divergence may be an important driver of rapid diversification in addition to ecomorphological evolution. However, this pattern may depend on the phylogenetic scale at which rate heterogeneity is examined.

  12. Baseline investigations of bats and birds at Wind Turbine Test Centre Østerild

    DEFF Research Database (Denmark)

    The Department of Bioscience, Aarhus University was commissioned by the Danish Nature Agency to undertake a bat and bird monitoring programme prior to the construction of a national test centre for wind turbines near Østerild in Thy, Denmark. The occurrence and activity level of bats in Østerild...... Plantation and the vicinity were monitored in summer and autumn 2011. Bats were recorded on 57-100% of surveyed nights at individual wind turbine sites, ponds and lakes. A total of seven species were recorded. Pond bats were recorded at all sites and throughout the survey period in the plantation. Whooper......, the potential impacts of the combined structures on the bird species occurring in the study area were considered unlikely to be significant. However, given the uncertainties in the preliminary assessment, the post-construction programme will further investigate potential impacts on bats and birds....

  13. Megafans and Trumpeter Bird Biodiversity-Psophia Phylogeography and Landscape Evolution in Amazonia

    Science.gov (United States)

    Wilkinson, Justin

    2014-01-01

    Based on geomorphic character and mapped geology, geologists have interpreted the landscape surrounding the Andes Mountains as becoming progressively younger to the East. These sedimentary materials filled the late Miocene swampland that formerly occupied central and western Amazonia. Apart from the ancient landscapes of the Guiana Highlands (top right, figure 1a), Zone Ac is the oldest, followed by Zone Aw, within which megafan Jw is older than megafan Je (figure 1a). DNA-based paleogeography of the trumpeters shows that younger clades diverge from parent lineages with increasing distance from the Andes chain. Thus, Psophia napensis diverges from the P. crepitans parent, and P. ochroptera diverges from P. napensis. The P. ochroptera population is confined solely to the Je megafan (figure 1a). The same trend is seen on the south side of the Amazon depression. Since the timing of the events seems to be of exactly the same order [post-Miocene for the land surfaces and trumpeter divergence within the last 3 million years (figure 1d)], it seems reasonable to think that the megafans provided the substrate on which new bird lineages could speciate. Such physical controls of evolution are becoming more important in the understanding of biodiversity.

  14. Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population.

    Science.gov (United States)

    Pulido, Francisco; Berthold, Peter

    2010-04-20

    Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic adjustments are largely unknown. This knowledge is still crucial to predict whether populations of migratory birds will adapt to a rapid increase in temperature. We monitored migratory behavior in a population of blackcaps (Sylvia atricapilla) to test for evolutionary responses to recent climate change. Using a common garden experiment in time and captive breeding we demonstrated a genetic reduction in migratory activity and evolutionary change in phenotypic plasticity of migration onset. An artificial selection experiment further revealed that residency will rapidly evolve in completely migratory bird populations if selection for shorter migration distance persists. Our findings suggest that current alterations of the environment are favoring birds wintering closer to the breeding grounds and that populations of migratory birds have strongly responded to these changes in selection. The reduction of migratory activity is probably an important evolutionary process in the adaptation of migratory birds to climate change, because it reduces migration costs and facilitates the rapid adjustment to the shifts in the timing of food availability during reproduction.

  15. Dynamic evolution of the alpha (α) and beta (β) keratins has accompanied integument diversification and the adaptation of birds into novel lifestyles

    DEFF Research Database (Denmark)

    Greenwold, Matthew J.; Bao, Weier; Jarvis, Erich D.

    2014-01-01

    BACKGROUND: Vertebrate skin appendages are constructed of keratins produced by multigene families. Alpha (α) keratins are found in all vertebrates, while beta (β) keratins are found exclusively in reptiles and birds. We have studied the molecular evolution of these gene families in the genomes...... of 48 phylogenetically diverse birds and their expression in the scales and feathers of the chicken. RESULTS: We found that the total number of α-keratins is lower in birds than mammals and non-avian reptiles, yet two α-keratin genes (KRT42 and KRT75) have expanded in birds. The β-keratins, however...

  16. A 'Turing' Test for Landscape Evolution Models

    Science.gov (United States)

    Parsons, A. J.; Wise, S. M.; Wainwright, J.; Swift, D. A.

    2008-12-01

    Resolving the interactions among tectonics, climate and surface processes at long timescales has benefited from the development of computer models of landscape evolution. However, testing these Landscape Evolution Models (LEMs) has been piecemeal and partial. We argue that a more systematic approach is required. What is needed is a test that will establish how 'realistic' an LEM is and thus the extent to which its predictions may be trusted. We propose a test based upon the Turing Test of artificial intelligence as a way forward. In 1950 Alan Turing posed the question of whether a machine could think. Rather than attempt to address the question directly he proposed a test in which an interrogator asked questions of a person and a machine, with no means of telling which was which. If the machine's answer could not be distinguished from those of the human, the machine could be said to demonstrate artificial intelligence. By analogy, if an LEM cannot be distinguished from a real landscape it can be deemed to be realistic. The Turing test of intelligence is a test of the way in which a computer behaves. The analogy in the case of an LEM is that it should show realistic behaviour in terms of form and process, both at a given moment in time (punctual) and in the way both form and process evolve over time (dynamic). For some of these behaviours, tests already exist. For example there are numerous morphometric tests of punctual form and measurements of punctual process. The test discussed in this paper provides new ways of assessing dynamic behaviour of an LEM over realistically long timescales. However challenges remain in developing an appropriate suite of challenging tests, in applying these tests to current LEMs and in developing LEMs that pass them.

  17. Macroevolutionary speciation rates are decoupled from the evolution of intrinsic reproductive isolation in Drosophila and birds.

    Science.gov (United States)

    Rabosky, Daniel L; Matute, Daniel R

    2013-09-17

    The rate at which speciation occurs varies greatly among different kinds of organisms and is frequently assumed to result from species- or clade-specific factors that influence the rate at which populations acquire reproductive isolation. This premise leads to a fundamental prediction that has never been tested: Organisms that quickly evolve prezygotic or postzygotic reproductive isolation should have faster rates of speciation than organisms that slowly acquire reproductive isolation. We combined phylogenetic estimates of speciation rates from Drosophila and birds with a method for analyzing interspecific hybridization data to test whether the rate at which individual lineages evolve reproductive isolation predicts their macroevolutionary rate of species formation. We find that some lineages evolve reproductive isolation much more quickly than others, but this variation is decoupled from rates of speciation as measured on phylogenetic trees. For the clades examined here, reproductive isolation--especially intrinsic, postzygotic isolation--does not seem to be the rate-limiting control on macroevolutionary diversification dynamics. These results suggest that factors associated with intrinsic reproductive isolation may have less to do with the tremendous variation in species diversity across the evolutionary tree of life than is generally assumed.

  18. Partial migration in birds: tests of three hypotheses in a tropical lekking frugivore.

    Science.gov (United States)

    Boyle, W Alice

    2008-11-01

    1. Partially migratory species provide opportunities to understand which ecological factors cause some animals to migrate when others remain resident year round. Partial migration in birds has been explained by the dominance, arrival-time, and body-size hypotheses. 2. Testing these hypotheses has proven difficult due to the similarities of the predictions they make in temperate-breeding long-distance migrants. In tropical altitudinal migrants, however, these hypotheses make different predictions regarding the sex, age, and condition of migrants and residents. 3. Among white-ruffed manakins in Costa Rica, young birds were not more likely to migrate (as predicted by the dominance hypothesis), nor were females more likely to migrate (as predicted by the arrival-time hypothesis). All condition-related variables interacted with sex, together explaining much of the variation in migratory behaviour. 4. I re-articulate the body-size hypothesis in the context of tropical altitudinal bird migration, focusing explicitly on how limited foraging opportunities and differences in individual condition affect fasting ability during torrential rains. Despite ample food, the smallest birds or those stressed by parasites or moult may risk starvation at breeding elevations due to a reduction in foraging time. These results highlight how intrinsic and extrinsic factors may interact to produce observed patterns of within- and among-species variation in migratory behaviour.

  19. Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds.

    Science.gov (United States)

    Birchard, Geoffrey F; Ruta, Marcello; Deeming, D Charles

    2013-08-23

    A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be distinguished by conventional allometry because of the confounding effects of phylogeny and hatchling maturity. Precociality of young but not paternal care in the theropod ancestors of birds is consistent with the available data.

  20. Evolution of embryonic developmental period in the marine bird families Alcidae and Spheniscidae: roles for nutrition and predation?

    Directory of Open Access Journals (Sweden)

    Vos Rutger A

    2010-06-01

    Full Text Available Abstract Background Nutrition and predation have been considered two primary agents of selection important in the evolution of avian life history traits. The relative importance of these natural selective forces in the evolution of avian embryonic developmental period (EDP remain poorly resolved, perhaps in part because research has tended to focus on a single, high taxonomic-level group of birds: Order Passeriformes. The marine bird families Alcidae (auks and Spheniscidae (penguins exhibit marked variation in EDP, as well as behavioural and ecological traits ultimately linked to EDP. Therefore, auks and penguins provide a unique opportunity to assess the natural selective basis of variation in a key life-history trait at a low taxonomic-level. We used phylogenetic comparative methods to investigate the relative importance of behavioural and ecological factors related to nutrition and predation in the evolution of avian EDP. Results Three behavioural and ecological variables related to nutrition and predation risk (i.e., clutch size, activity pattern, and nesting habits were significant predictors of residual variation in auk and penguin EDP based on models predicting EDP from egg mass. Species with larger clutch sizes, diurnal activity patterns, and open nests had significantly shorter EDPs. Further, EDP was found to be longer among birds which forage in distant offshore waters, relative to those that foraged in near shore waters, in line with our predictions, but not significantly so. Conclusion Current debate has emphasized predation as the primary agent of selection driving avian life history diversification. Our results suggest that both nutrition and predation have been important selective forces in the evolution of auk and penguin EDP, and highlight the importance of considering these questions at lower taxonomic scales. We suggest that further comparative studies on lower taxonomic-level groups will continue to constructively inform the

  1. New developmental evidence clarifies the evolution of wrist bones in the dinosaur-bird transition.

    Science.gov (United States)

    Botelho, João Francisco; Ossa-Fuentes, Luis; Soto-Acuña, Sergio; Smith-Paredes, Daniel; Nuñez-León, Daniel; Salinas-Saavedra, Miguel; Ruiz-Flores, Macarena; Vargas, Alexander O

    2014-09-01

    From early dinosaurs with as many as nine wrist bones, modern birds evolved to develop only four ossifications. Their identity is uncertain, with different labels used in palaeontology and developmental biology. We examined embryos of several species and studied chicken embryos in detail through a new technique allowing whole-mount immunofluorescence of the embryonic cartilaginous skeleton. Beyond previous controversy, we establish that the proximal-anterior ossification develops from a composite radiale+intermedium cartilage, consistent with fusion of radiale and intermedium observed in some theropod dinosaurs. Despite previous claims that the development of the distal-anterior ossification does not support the dinosaur-bird link, we found its embryonic precursor shows two distinct regions of both collagen type II and collagen type IX expression, resembling the composite semilunate bone of bird-like dinosaurs (distal carpal 1+distal carpal 2). The distal-posterior ossification develops from a cartilage referred to as "element x," but its position corresponds to distal carpal 3. The proximal-posterior ossification is perhaps most controversial: It is labelled as the ulnare in palaeontology, but we confirm the embryonic ulnare is lost during development. Re-examination of the fossil evidence reveals the ulnare was actually absent in bird-like dinosaurs. We confirm the proximal-posterior bone is a pisiform in terms of embryonic position and its development as a sesamoid associated to a tendon. However, the pisiform is absent in bird-like dinosaurs, which are known from several articulated specimens. The combined data provide compelling evidence of a remarkable evolutionary reversal: A large, ossified pisiform re-evolved in the lineage leading to birds, after a period in which it was either absent, nonossified, or very small, consistently escaping fossil preservation. The bird wrist provides a modern example of how developmental and paleontological data illuminate

  2. New Developmental Evidence Clarifies the Evolution of Wrist Bones in the Dinosaur–Bird Transition

    Science.gov (United States)

    Botelho, João Francisco; Ossa-Fuentes, Luis; Soto-Acuña, Sergio; Smith-Paredes, Daniel; Nuñez-León, Daniel; Salinas-Saavedra, Miguel; Ruiz-Flores, Macarena; Vargas, Alexander O.

    2014-01-01

    From early dinosaurs with as many as nine wrist bones, modern birds evolved to develop only four ossifications. Their identity is uncertain, with different labels used in palaeontology and developmental biology. We examined embryos of several species and studied chicken embryos in detail through a new technique allowing whole-mount immunofluorescence of the embryonic cartilaginous skeleton. Beyond previous controversy, we establish that the proximal–anterior ossification develops from a composite radiale+intermedium cartilage, consistent with fusion of radiale and intermedium observed in some theropod dinosaurs. Despite previous claims that the development of the distal–anterior ossification does not support the dinosaur–bird link, we found its embryonic precursor shows two distinct regions of both collagen type II and collagen type IX expression, resembling the composite semilunate bone of bird-like dinosaurs (distal carpal 1+distal carpal 2). The distal–posterior ossification develops from a cartilage referred to as “element x,” but its position corresponds to distal carpal 3. The proximal–posterior ossification is perhaps most controversial: It is labelled as the ulnare in palaeontology, but we confirm the embryonic ulnare is lost during development. Re-examination of the fossil evidence reveals the ulnare was actually absent in bird-like dinosaurs. We confirm the proximal–posterior bone is a pisiform in terms of embryonic position and its development as a sesamoid associated to a tendon. However, the pisiform is absent in bird-like dinosaurs, which are known from several articulated specimens. The combined data provide compelling evidence of a remarkable evolutionary reversal: A large, ossified pisiform re-evolved in the lineage leading to birds, after a period in which it was either absent, nonossified, or very small, consistently escaping fossil preservation. The bird wrist provides a modern example of how developmental and paleontological

  3. Testing the environmental Kuznets curve hypothesis with bird populations as habitat-specific environmental indicators: evidence from Canada.

    Science.gov (United States)

    Lantz, Van; Martínez-Espiñeira, Roberto

    2008-04-01

    The traditional environmental Kuznets curve (EKC) hypothesis postulates that environmental degradation follows an inverted U-shaped relationship with gross domestic product (GDP) per capita. We tested the EKC hypothesis with bird populations in 5 different habitats as environmental quality indicators. Because birds are considered environmental goods, for them the EKC hypothesis would instead be associated with a U-shaped relationship between bird populations and GDP per capita. In keeping with the literature, we included other variables in the analysis-namely, human population density and time index variables (the latter variable captured the impact of persistent and exogenous climate and/or policy changes on bird populations over time). Using data from 9 Canadian provinces gathered over 37 years, we used a generalized least-squares regression for each bird habitat type, which accounted for the panel structure of the data, the cross-sectional dependence across provinces in the residuals, heteroskedasticity, and fixed- or random-effect specifications of the models. We found evidence that supports the EKC hypothesis for 3 of the 5 bird population habitat types. In addition, the relationship between human population density and the different bird populations varied, which emphasizes the complex nature of the impact that human populations have on the environment. The relationship between the time-index variable and the different bird populations also varied, which indicates there are other persistent and significant influences on bird populations over time. Overall our EKC results were consistent with those found for threatened bird species, indicating that economic prosperity does indeed act to benefit some bird populations.

  4. Discovery of the elusive leptin in birds: identification of several 'missing links' in the evolution of leptin and its receptor.

    Directory of Open Access Journals (Sweden)

    Jeremy W Prokop

    Full Text Available Leptin is a pleiotropic protein best known for regulation of appetite and fat storage in mammals. While many leptin orthologs have been identified among vertebrates, an authentic leptin in birds has remained elusive and controversial. Here we identify leptin sequence from the Peregrine falcon, Falco peregrinus (pfleptin, and identify sequences from two other birds (mallard and zebra finch, and 'missing' vertebrates (elephant shark, alligator, Indian python, Chinese soft-shelled turtle, and coelacanth. The pattern of genes surrounding leptin (snd1, rbm28 is syntenic between the falcon and mammalian genomes. Phylogenetic analysis of all known leptin protein sequences improves our understanding of leptin's evolution. Structural modeling of leptin orthologs highlights a highly conserved hydrophobic core in the four-helix cytokine packing domain. A docked model of leptin with the leptin receptor for Peregrine falcon reveals several conserved amino acids important for the interaction and possible coevolution of leptin with its receptor. We also show for the first time, an authentic avian leptin sequence that activates the JAK-STAT signaling pathway. These newly identified sequences, structures, and tools for avian leptin and its receptor will allow elucidation of the function of these proteins in feral and domestic birds.

  5. Performance of Encounternet Tags: Field Tests of Miniaturized Proximity Loggers for Use on Small Birds.

    Directory of Open Access Journals (Sweden)

    Iris I Levin

    Full Text Available Proximity logging is a new tool for understanding social behavior as it allows for accurate quantification of social networks. We report results from field calibration and deployment tests of miniaturized proximity tags (Encounternet, digital transceivers that log encounters between tagged individuals. We examined radio signal behavior in relation to tag attachment (tag, tag on bird, tag on saline-filled balloon to understand how radio signal strength is affected by the tag mounting technique used for calibration tests. We investigated inter-tag and inter-receiver station variability, and in each calibration test we accounted for the effects of antennae orientation. Additionally, we used data from a live deployment on breeding barn swallows (Hirundo rustica erythrogaster to analyze the quality of the logs, including reciprocal agreement in dyadic logs. We evaluated the impact (in terms of mass changes of tag attachment on the birds. We were able to statistically distinguish between RSSI values associated with different close-proximity (<5 m tag-tag distances regardless of antennae orientation. Inter-tag variability was low, but we did find significant inter-receiver station variability. Reciprocal agreement of dyadic logs was high and social networks were constructed from proximity tag logs based on two different RSSI thresholds. There was no evidence of significant mass loss in the time birds were wearing tags. We conclude that proximity loggers are accurate and effective for quantifying social behavior. However, because RSSI and distance cannot be perfectly resolved, data from proximity loggers are most appropriate for comparing networks based on specific RSSI thresholds. The Encounternet system is flexible and customizable, and tags are now light enough for use on small animals (<50 g.

  6. Performance of Encounternet Tags: Field Tests of Miniaturized Proximity Loggers for Use on Small Birds

    Science.gov (United States)

    Levin, Iris I.; Zonana, David M.; Burt, John M.; Safran, Rebecca J.

    2015-01-01

    Proximity logging is a new tool for understanding social behavior as it allows for accurate quantification of social networks. We report results from field calibration and deployment tests of miniaturized proximity tags (Encounternet), digital transceivers that log encounters between tagged individuals. We examined radio signal behavior in relation to tag attachment (tag, tag on bird, tag on saline-filled balloon) to understand how radio signal strength is affected by the tag mounting technique used for calibration tests. We investigated inter-tag and inter-receiver station variability, and in each calibration test we accounted for the effects of antennae orientation. Additionally, we used data from a live deployment on breeding barn swallows (Hirundo rustica erythrogaster) to analyze the quality of the logs, including reciprocal agreement in dyadic logs. We evaluated the impact (in terms of mass changes) of tag attachment on the birds. We were able to statistically distinguish between RSSI values associated with different close-proximity (<5m) tag-tag distances regardless of antennae orientation. Inter-tag variability was low, but we did find significant inter-receiver station variability. Reciprocal agreement of dyadic logs was high and social networks were constructed from proximity tag logs based on two different RSSI thresholds. There was no evidence of significant mass loss in the time birds were wearing tags. We conclude that proximity loggers are accurate and effective for quantifying social behavior. However, because RSSI and distance cannot be perfectly resolved, data from proximity loggers are most appropriate for comparing networks based on specific RSSI thresholds. The Encounternet system is flexible and customizable, and tags are now light enough for use on small animals (<50g). PMID:26348329

  7. Performance of Encounternet Tags: Field Tests of Miniaturized Proximity Loggers for Use on Small Birds.

    Science.gov (United States)

    Levin, Iris I; Zonana, David M; Burt, John M; Safran, Rebecca J

    2015-01-01

    Proximity logging is a new tool for understanding social behavior as it allows for accurate quantification of social networks. We report results from field calibration and deployment tests of miniaturized proximity tags (Encounternet), digital transceivers that log encounters between tagged individuals. We examined radio signal behavior in relation to tag attachment (tag, tag on bird, tag on saline-filled balloon) to understand how radio signal strength is affected by the tag mounting technique used for calibration tests. We investigated inter-tag and inter-receiver station variability, and in each calibration test we accounted for the effects of antennae orientation. Additionally, we used data from a live deployment on breeding barn swallows (Hirundo rustica erythrogaster) to analyze the quality of the logs, including reciprocal agreement in dyadic logs. We evaluated the impact (in terms of mass changes) of tag attachment on the birds. We were able to statistically distinguish between RSSI values associated with different close-proximity (orientation. Inter-tag variability was low, but we did find significant inter-receiver station variability. Reciprocal agreement of dyadic logs was high and social networks were constructed from proximity tag logs based on two different RSSI thresholds. There was no evidence of significant mass loss in the time birds were wearing tags. We conclude that proximity loggers are accurate and effective for quantifying social behavior. However, because RSSI and distance cannot be perfectly resolved, data from proximity loggers are most appropriate for comparing networks based on specific RSSI thresholds. The Encounternet system is flexible and customizable, and tags are now light enough for use on small animals (<50 g).

  8. Are nest sites actively chosen? Testing a common assumption for three non-resource limited birds

    Science.gov (United States)

    Goodenough, A. E.; Elliot, S. L.; Hart, A. G.

    2009-09-01

    Many widely-accepted ecological concepts are simplified assumptions about complex situations that remain largely untested. One example is the assumption that nest-building species choose nest sites actively when they are not resource limited. This assumption has seen little direct empirical testing: most studies on nest-site selection simply assume that sites are chosen actively (and seek explanations for such behaviour) without considering that sites may be selected randomly. We used 15 years of data from a nestbox scheme in the UK to test the assumption of active nest-site choice in three cavity-nesting bird species that differ in breeding and migratory strategy: blue tit ( Cyanistes caeruleus), great tit ( Parus major) and pied flycatcher ( Ficedula hypoleuca). Nest-site selection was non-random (implying active nest-site choice) for blue and great tits, but not for pied flycatchers. We also considered the relative importance of year-specific and site-specific factors in determining occupation of nest sites. Site-specific factors were more important than year-specific factors for the tit species, while the reverse was true for pied flycatchers. Our results show that nest-site selection, in birds at least, is not always the result of active choice, such that choice should not be assumed automatically in studies of nesting behaviour. We use this example to highlight the need to test key ecological assumptions empirically, and the importance of doing so across taxa rather than for single "model" species.

  9. Evolution of genotoxicity test methods in Japan.

    Science.gov (United States)

    Sofuni, Toshio

    2017-01-01

    The evolution of methods to assess genotoxicity of test compounds is thought to be one of the important subjects in The Japanese Environmental and Mutagen Society (JEMS). In 1970, the Ministry of Education of Japan (at that time) organized a research group (Organizer: Y. Tazima, National Institute of Genetics), and started a systematic research on the genotoxic effects induced by chemical substances. Considering the importance of this issue through the outcomes of the research group, JEMS was established in 1972, and President Tazima organized the 1st annual meeting in the August in Tokyo with the participation of experts in this field working in national institutes, universities and others in Japan. The discovery that food additives possessed genotoxic potential triggered various scientific activities in the field of genotoxicity. Another important point was the correlation between genotoxicity and carcinogenicity, in which the establishment of the reverse mutation assay played an important role. Other critical factors, such as side effects of drugs, occupational cancer, and environmental pollution due to genotoxic chemicals, emphasized the importance of genotoxicity tests for human safety. The tests performed to assess genotoxicity from 1960s to 1980s will be described to understand that many different genotoxic methodologies were discussed in these periods.

  10. Timing and proximate causes of mortality in wild bird populations: testing Ashmole’s hypothesis

    Science.gov (United States)

    Barton, Daniel C.; Martin, Thomas E.

    2012-01-01

    Fecundity in birds is widely recognized to increase with latitude across diverse phylogenetic groups and regions, yet the causes of this variation remain enigmatic. Ashmole’s hypothesis is one of the most broadly accepted explanations for this pattern. This hypothesis suggests that increasing seasonality leads to increasing overwinter mortality due to resource scarcity during the lean season (e.g., winter) in higher latitude climates. This mortality is then thought to yield increased per-capita resources for breeding that allow larger clutch sizes at high latitudes. Support for this hypothesis has been based on indirect tests, whereas the underlying mechanisms and assumptions remain poorly explored. We used a meta-analysis of over 150 published studies to test two underlying and critical assumptions of Ashmole’s hypothesis: first, that ad ult mortality is greatest during the season of greatest resource scarcity, and second, t hat most mortality is caused by starvation. We found that the lean season (winter) was generally not the season of greatest mortality. Instead, spring or summer was most frequently the season of greatest mortality. Moreover, monthly survival rates were not explained by monthly productivity, again opposing predictions from Ashmole’s hypothesis. Finally, predation, rather than starvation, was the most frequent proximate cause o f mortality. Our results do not support the mechanistic predictions of Ashmole‘s hypothesis, and suggest alternative explanations of latitudinal variation in clutch size should remain under consideration. Our meta-analysis also highlights a paucity of data available on the timing and causes of mortality in many bird populations, particularly tropical bird populations, despite the clear theoretical and empirical importance of such data.

  11. The impact of rise of the Andes and Amazon landscape evolution on diversification of lowland terra-firme forest birds

    Science.gov (United States)

    Aleixo, A.; Wilkinson, M. J.

    2011-12-01

    Since the 19th Century, the unmatched biological diversity of Amazonia has stimulated a diverse set of hypotheses accounting for patterns of species diversity and distribution in mega-diverse tropical environments. Unfortunately, the evidence supporting particular hypotheses to date is at best described as ambiguous, and no generalizations have emerged yet, mostly due to the lack of comprehensive comparative phylogeographic studies with thorough trans-Amazonian sampling of lineages. Here we report on spatial and temporal patterns of diversification estimated from mitochondrial gene trees for 31 lineages of birds associated with upland terra-firme forest, the dominant habitat in modern lowland Amazonia. The results confirm the pervasive role of Amazonian rivers as primary barriers separating sister lineages of birds, and a protracted spatio-temporal pattern of diversification, with a gradual reduction of earlier (1st and 2nd) and older (> 2 mya) splits associated with each lineage in an eastward direction (the easternmost tributaries of the Amazon, the Xingu and Tocantins Rivers, are not associated with any splits older than > 2 mya). This "younging-eastward" pattern may have an abiotic explanation related to landscape evolution. Triggered by a new pulse of Andean uplift, it has been proposed that modern Amazon basin landscapes may have evolved successively eastward, away from the mountain chain, starting ~10 mya. This process was likely based on the deposition of vast fluvial sediment masses, known as megafans, which apparently extended in series progressively eastward from Andean sources. The effects on drainage patterns are apparent from the location of axial rivers such as the Negro / Orinoco and Madeira which lie at the distal ends of major megafan ramparts at cratonic margins furthest from the Andes. Megafan extension plausibly explains the progressive extinction of the original Pebas wetland of west-central Amazonia by the present fluvial landsurfaces where

  12. Tropical field endocrinology: ecology and evolution of testosterone concentrations in male birds.

    Science.gov (United States)

    Hau, Michaela; Gill, Sharon A; Goymann, Wolfgang

    2008-07-01

    Comparative research on natural populations of vertebrates, in particular avian species, has been instrumental in documenting the existence of interspecific variation in the hormonal regulation of behavior. Studies on tropical birds, which tend to experience ecological conditions that diverge from those of higher latitude birds, have been invaluable in showcasing such variation. Here we review recent advances in tropical avian field endocrinology, focusing on male circulating testosterone concentrations during the breeding season. We summarize the evidence for a decrease in male circulating testosterone concentrations from high towards low latitudes. We revisit both established and recently proposed ecological hypotheses that attempt to explain the existence of this pattern, as well as the variation in testosterone concentrations and dynamics within tropical populations of birds. We highlight additional social and life history variables that may need to be considered if we aim at gaining an integrated understanding of the ultimate factors that influence the relationship between hormonal signals and behavioral traits in natural populations. Understanding the ecological factors that influence circulating hormone concentrations will be an important first step in our understanding of the evolutionary processes that are at the basis of variations in hormone-behavior connections. Such findings should be supplemented by studies on functional aspects of the testosterone signal at the organismal and cellular level.

  13. Testing AGN feedback models in galaxy evolution

    Science.gov (United States)

    Shin, Min-Su

    Galaxy formation and evolution have been one of the most challenging problems in astrophysics. A single galaxy has various components (stars, atomic and molecular gas, a supermassive black hole, and dark matter) and has interacted with its cosmic environment throughout its history. A key issue in understanding galaxy evolution is to find the dominant physical processes in the interactions between the components of a galaxy and between a galaxy and its environment. AGN feedback has been proposed as a key process to suppress late star formation in massive elliptical galaxies and as a general consequence of galaxy mergers and interactions. In this thesis, I investigate feedback effects from active galactic nuclei (AGN) using a new simulation code and data from the Sloan Digital Sky Survey. In the first chapter, I test purely mechanical AGN feedback models via a nuclear wind around the central SMBH in elliptical galaxies by comparing simulation results to four well-defined observational constraints: the mass ratio between the SMBH and its host galaxy, the lifetime of the quasar phase, the X-ray luminosity from the hot interstellar medium, and the mass fraction of young stars. Even though purely mechanical AGN feedback is commonly assumed in cosmological simulations, I find that it is inadequate, and cannot reproduce all four observational constraints simultaneously. This result suggests that both mechanical and radiative feedback modes are important physical processes. In the second chapter, I simulate the coevolution of the SMBH and its host galaxy under different environments, represented by different amounts of gas stripping. Though the connection between environment and galaxy evolution has been well-studied, environmental effects on the growth of the SMBH have not been answered yet. I find that strong gas stripping, which satellite galaxies might experience, highly suppresses SMBH mass accretion and AGN activity. Moreover, the suppression of the SMBH growth is

  14. Linkages between the life-history evolution of tropical and temperate birds and the resistance of cultured skin fibroblasts to oxidative and non-oxidative chemical injury.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Harper, James M; Queenborough, Simon A; Williams, Joseph B

    2013-04-15

    A fundamental challenge facing physiological ecologists is to understand how variation in life history at the whole-organism level might be linked to cellular function. Thus, because tropical birds have higher annual survival and lower rates of metabolism, we hypothesized that cells from tropical species would have greater cellular resistance to chemical injury than cells from temperate species. We cultured dermal fibroblasts from 26 tropical and 26 temperate species of birds and examined cellular resistance to cadmium, H(2)O(2), paraquat, thapsigargin, tunicamycium, methane methylsulfonate (MMS) and UV light. Using ANCOVA, we found that the values for the dose that killed 50% of cells (LD(50)) from tropical birds were significantly higher for H(2)O(2) and MMS. When we tested for significance using a generalized least squares approach accounting for phylogenetic relationships among species to model LD(50), we found that cells from tropical birds had greater tolerance for Cd, H(2)O(2), paraquat, tunicamycin and MMS than cells from temperate birds. In contrast, tropical birds showed either lower or no difference in tolerance to thapsigargin and UV light in comparison with temperate birds. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to be more resistant to forms of oxidative and non-oxidative stress than cells from shorter-lived temperate species.

  15. The Impact of Rise of the Andes and Amazon Landscape Evolution on Diversification of Lowland terra-firme Forest Birds

    Science.gov (United States)

    Aleixo, Alexandre; Wilkinson, M. Justin

    2011-01-01

    Since the 19th Century, the unmatched biological diversity of Amazonia has stimulated a diverse set of hypotheses accounting for patterns of species diversity and distribution in mega-diverse tropical environments. Unfortunately, the evidence supporting particular hypotheses to date is at best described as ambiguous, and no generalizations have emerged yet, mostly due to the lack of comprehensive comparative phylogeographic studies with thorough trans-Amazonian sampling of lineages. Here we report on spatial and temporal patterns of diversification estimated from mitochondrial gene trees for 31 lineages of birds associated with upland terra-firme forest, the dominant habitat in modern lowland Amazonia. The results confirm the pervasive role of Amazonian rivers as primary barriers separating sister lineages of birds, and a protracted spatio-temporal pattern of diversification, with a gradual reduction of earlier (1st and 2nd) and older (> 2 mya) splits associated with each lineage in an eastward direction. (The easternmost tributaries of the Amazon, the Xingu and Tocantins Rivers, are not associated with any splits older than > 2 mya). For the suboscine passerines, maximum-likelihood estimates of rates of diversification point to an overall constant rate over the past 5 my (up to a significant downturn at 300,000 y ago). This "younging-eastward" pattern may have an abiotic explanation related to landscape evolution. Triggered by a new pulse of Andean uplift, it has been proposed that modern Amazon basin landscapes may have evolved successively eastward, away from the mountain chain, starting approximately 10 mya. This process was likely based on the deposition of vast fluvial sediment masses, known as megafans, that may have extended progressively and in series eastward from Andean sources. This process plausibly explains the progressive extinction of original Pebas wetland of western-central Amazonia by the present fluvial landsurfaces of a more terra-firme type

  16. Tests on ticks from wild birds collected in the eastern United States for rickettsiae and viruses

    Science.gov (United States)

    Clifford, C.M.; Sonenshine, D.E.; Atwood, E.L.; Robbins, C.S.; Hughes, L.E.

    1969-01-01

    Results of tests for rickettsiae and viruses on 4,266 ticks taken from more than 10,000 birds, comprising 150 species, in the eastern United States indicated the presence of two agents: Rickettsia rickettsii and an agent of the typhus group. Infection with R. rickettsii was indicated in 24 pools of Haemaphysalis leporispalustris, five pools of Ixodes dentatus, one pool of Ixodes brunneus, and two pools that contained both I. dentatus and H. leporispalustris. The pools positive for R. rickettsii were from a variety of locations in the eastern U. S. The typhus-group agent was demonstrated only once, in a single pool of H. leporispalustris taken at Kent Point, Maryland. A strain of R. rickettsii was isolated from a pool of 21 larval H. leporispalustris collected at Ocean City, Maryland. This agent possessed several characteristics of other strains of low virulence isolated previously in this region by various authors.

  17. The Question of Evolution in the Buddhist Ecology of Thalia Field’s Bird Lovers, Backyard

    Directory of Open Access Journals (Sweden)

    Gillian Parrish

    2011-01-01

    Full Text Available Thalia Field’s work, which she has described as an “ecology of questions,” inhabitsthe edges of genres, where she grows her verbal environments of researched materialanimated by her asking. Her most recent book, Bird Lovers, Backyard (New Directions,2010, spins itself from the twigs and strands and of terminologies ranging fromarchitecture to zoology as she tracks questions of language, behavior, and relationshipsbetween species. “Whose Umwelt is it anyway?” she asks in this extended study ofhuman behavior and the uses of language in how we interpret and shape the world forourselves and other life forms.Through this exploration of human contradictions and miscommunicationbetween species, Field makes a nest for an egg that is a question of possibilities—forBird Lovers, Backyard is also a kind of future studies for human potential, operating byway of past example, telling tales of what might amount to a “series of mistakes.”Kicking off this inquiry into what we might be, the book opens with an epigraph fromher young son that slyly functions as a kind of crossroads: “What if everyone in theworld wasn’t nice?” asks the child—a question that may serve as a hardnosed premisefor going forth into the world or as a challenge, a call to grow up.And here, for a reader looking, Field’s submerged Buddhist outlook catches thelight. For in her allegiance to an agile balance of “nichelessness,” Field keepsBuddhism—fitting its central idea of interdependent origination—as but one strand inthe weave of her influences. In the book’s third poem-essay “This Crime Has a Name,”which this paper will focus on, Tibetan Buddhist figures and ideas form a part of anecosystem that encompasses industrial design, biosemiotics, and Chinese logicianswherein she thinks through the displacement of sparrow by spaceman, asking whatextinction looks like and what our species might mean.

  18. Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

    Directory of Open Access Journals (Sweden)

    David L Swanson

    Full Text Available The underlying assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR and maximal aerobic metabolic rates are phenotypically linked. However, because BMR is largely a function of central organs whereas maximal metabolic output is largely a function of skeletal muscles, the mechanistic underpinnings for their linkage are not obvious. Interspecific studies in birds generally support a phenotypic correlation between BMR and maximal metabolic output. If the aerobic capacity model is valid, these phenotypic correlations should also extend to intraspecific comparisons. We measured BMR, M(sum (maximum thermoregulatory metabolic rate and MMR (maximum exercise metabolic rate in a hop-flutter chamber in winter for dark-eyed juncos (Junco hyemalis, American goldfinches (Carduelis tristis; M(sum and MMR only, and black-capped chickadees (Poecile atricapillus; BMR and M(sum only and examined correlations among these variables. We also measured BMR and M(sum in individual house sparrows (Passer domesticus in both summer, winter and spring. For both raw metabolic rates and residuals from allometric regressions, BMR was not significantly correlated with either M(sum or MMR in juncos. Moreover, no significant correlation between M(sum and MMR or their mass-independent residuals occurred for juncos or goldfinches. Raw BMR and M(sum were significantly positively correlated for black-capped chickadees and house sparrows, but mass-independent residuals of BMR and M(sum were not. These data suggest that central organ and exercise organ metabolic levels are not inextricably linked and that muscular capacities for exercise and shivering do not necessarily vary in tandem in individual birds. Why intraspecific and interspecific avian studies show differing results and the significance of these differences to the aerobic capacity model are unknown, and resolution of these questions will require additional studies of potential

  19. The PHA test reflects acquired T-cell mediated immunocompetence in birds.

    Directory of Open Access Journals (Sweden)

    José L Tella

    Full Text Available BACKGROUND: cological immunology requires techniques to reliably measure immunocompetence in wild vertebrates. The PHA-skin test, involving subcutaneous injection of a mitogen (phytohemagglutinin, PHA and measurement of subsequent swelling as a surrogate of T-cell mediated immunocompetence, has been the test of choice due to its practicality and ease of use in the field. However, mechanisms involved in local immunological and inflammatory processes provoked by PHA are poorly known, and its use and interpretation as an acquired immune response is currently debated. METHODOLOGY: Here, we present experimental work using a variety of parrot species, to ascertain whether PHA exposure produces larger secondary than primary responses as expected if the test reflects acquired immunocompetence. Moreover, we simultaneously quantified T-lymphocyte subsets (CD4(+, CD5(+ and CD8(+ and plasma proteins circulating in the bloodstream, potentially involved in the immunological and inflammatory processes, through flow cytometry and electrophoresis. PRINCIPAL FINDINGS: Our results showed stronger responses after a second PHA injection, independent of species, time elapsed and changes in body mass of birds between first and second injections, thus supporting the adaptive nature of this immune response. Furthermore, the concomitant changes in the plasma concentrations of T-lymphocyte subsets and globulins indicate a causal link between the activation of the T-cell mediated immune system and local tissue swelling. CONCLUSIONS/SIGNIFICANCE: These findings justify the widespread use of the PHA-skin test as a reliable evaluator of acquired T-cell mediated immunocompetence in diverse biological disciplines. Further experimental research should be aimed at evaluating the relative role of innate immunocompetence in wild conditions, where the access to dietary proteins varies more than in captivity, and to ascertain how PHA responses relate to particular host

  20. The evolution of endothermy and its diversity in mammals and birds.

    Science.gov (United States)

    Grigg, Gordon C; Beard, Lyn A; Augee, Michael L

    2004-01-01

    Many elements of mammalian and avian thermoregulatory mechanisms are present in reptiles, and the changes involved in the transition to endothermy are more quantitative than qualitative. Drawing on our experience with reptiles and echidnas, we comment on that transition and on current theories about how it occurred. The theories divide into two categories, depending on whether selection pressures operated directly or indirectly on mechanisms producing heat. Both categories of theories focus on explaining the evolution of homeothermic endothermy but ignore heterothermy. However, noting that hibernation and torpor are almost certainly plesiomorphic (=ancestral, primitive), and that heterothermy is very common among endotherms, we propose that homeothermic endothermy evolved via heterothermy, with the earliest protoendotherms being facultatively endothermic and retaining their ectothermic capacity for "constitutional eurythermy." Thus, unlike current models for the evolution of endothermy that assume that hibernation and torpor are specialisations arising from homeothermic ancestry, and therefore irrelevant, we consider that they are central. We note the sophistication of thermoregulatory behavior and control in reptiles, including precise control over conductance, and argue that brooding endothermy seen in some otherwise ectothermic Boidae suggests an incipient capacity for facultative endothermy in reptiles. We suggest that the earliest insulation in protoendotherms may have been internal, arising from redistribution of the fat bodies that are typical of reptiles. We note that short-beaked echidnas provide a useful living model of what an (advanced) protoendotherm may have been like. Echidnas have the advantages of endothermy, including the capacity for homeothermic endothermy during incubation, but are very relaxed in their thermoregulatory precision and minimise energetic costs by using ectothermy facultatively when entering short- or long-term torpor. They also

  1. An integrative approach to understanding bird origins.

    Science.gov (United States)

    Xu, Xing; Zhou, Zhonghe; Dudley, Robert; Mackem, Susan; Chuong, Cheng-Ming; Erickson, Gregory M; Varricchio, David J

    2014-12-12

    Recent discoveries of spectacular dinosaur fossils overwhelmingly support the hypothesis that birds are descended from maniraptoran theropod dinosaurs, and furthermore, demonstrate that distinctive bird characteristics such as feathers, flight, endothermic physiology, unique strategies for reproduction and growth, and a novel pulmonary system originated among Mesozoic terrestrial dinosaurs. The transition from ground-living to flight-capable theropod dinosaurs now probably represents one of the best-documented major evolutionary transitions in life history. Recent studies in developmental biology and other disciplines provide additional insights into how bird characteristics originated and evolved. The iconic features of extant birds for the most part evolved in a gradual and stepwise fashion throughout archosaur evolution. However, new data also highlight occasional bursts of morphological novelty at certain stages particularly close to the origin of birds and an unavoidable complex, mosaic evolutionary distribution of major bird characteristics on the theropod tree. Research into bird origins provides a premier example of how paleontological and neontological data can interact to reveal the complexity of major innovations, to answer key evolutionary questions, and to lead to new research directions. A better understanding of bird origins requires multifaceted and integrative approaches, yet fossils necessarily provide the final test of any evolutionary model.

  2. The early Eocene birds of the Messel fossil site: a 48 million-year-old bird community adds a temporal perspective to the evolution of tropical avifaunas.

    Science.gov (United States)

    Mayr, Gerald

    2016-04-08

    Birds play an important role in studies addressing the diversity and species richness of tropical ecosystems, but because of the poor avian fossil record in all extant tropical regions, a temporal perspective is mainly provided by divergence dates derived from calibrated molecular analyses. Tropical ecosystems were, however, widespread in the Northern Hemisphere during the early Cenozoic, and the early Eocene German fossil site Messel in particular has yielded a rich avian fossil record. The Messel avifauna is characterized by a considerable number of flightless birds, as well as a high diversity of aerial insectivores and the absence of large arboreal birds. With about 70 currently known species in 42 named genus-level and at least 39 family-level taxa, it approaches extant tropical biotas in terms of species richness and taxonomic diversity. With regard to its taxonomic composition and presumed ecological characteristics, the Messel avifauna is more similar to the Neotropics, Madagascar, and New Guinea than to tropical forests in continental Africa and Asia. Because the former regions were geographically isolated during most of the Cenozoic, their characteristics may be due to the absence of biotic factors, especially those related to the diversification of placental mammals, which impacted tropical avifaunas in Africa and Asia. The crown groups of most avian taxa that already existed in early Eocene forests are species-poor. This does not support the hypothesis that the antiquity of tropical ecosystems is key to the diversity of tropical avifaunas, and suggests that high diversification rates may be of greater significance.

  3. Virginia ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, and gulls...

  4. Phytoestrogens and avian reproduction: Exploring the evolution and function of phytoestrogens and possible role of plant compounds in the breeding ecology of wild birds.

    Science.gov (United States)

    Rochester, Johanna R; Millam, James R

    2009-11-01

    Phytoestrogens are secondary plant compounds, which can act to mimic estrogen and cause the disruption of estrogenic responses in organisms. Although there is a substantial body of research studying phytoestrogens, including their mechanisms of estrogenic effects, evolution, and detection in biological systems, little is known about their ecological significance. There is evidence, however, that an ecological relationship involving phytoestrogens exists between plants and animals-plants may produce phytoestrogens to reduce fecundity of organisms that eat them. Birds and other vertebrates may also exploit phytoestrogens to regulate their own reproduction-there are well known examples of phytoestrogens inhibiting reproduction in higher vertebrates, including birds. Also, common plant stressors (e.g., high temperature) increase the production of secondary plant compounds, and, as evidence suggests, also induce phytoestrogen biosynthesis. These observations are consistent with the single study ever done on phytoestrogens and reproduction in wild birds [Leopold, A.S., Erwin, M., Oh, J., Browning, B., 1976. Phytoestrogens adverse effects on reproduction in California quail. Science 191, 98-100.], which found that drought stress correlated with increased levels of phytoestrogens in plants, and that increased phytoestrogen levels correlated with decreased young. This review discusses the hypothesis that plants may have an effect on the reproduction of avian species by producing phytoestrogens as a plant defense against herbivory, and that birds may "use" changing levels of phytoestrogens in the vegetation to ensure that food resources will support potential young produced. Evidence from our laboratory and others appear to support this hypothesis.

  5. Setback distances as a conservation tool in wildlife-human interactions: testing their efficacy for birds affected by vehicles on open-coast sandy beaches.

    Directory of Open Access Journals (Sweden)

    Thomas A Schlacher

    Full Text Available In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i most drivers did not create sizeable buffers between their vehicles and birds; ii bird disturbance was frequent; and iii predictors of probability of flushing (escape were setback distance and vehicle type (buses flushed birds at higher rates than cars. Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m and vehicle speeds to be slow (< 30 km h⁻¹. Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures, and rely on changes to current driver behaviour.

  6. First year post-construction monitoring of birds at Wind Turbine Test Centre Østerild

    DEFF Research Database (Denmark)

    Therkildsen, Ole Roland; Balsby, Thorsten Johannes Skovbjerg; Groom, Geoffrey Brian;

    2015-01-01

    swan, taiga bean goose, pink-footed goose, common crane, light-bellied brent goose, white-tailed eagle and nightjar were included as focal species in the ornithological investigations. In addition, species specific data on all bird species occurring regularly in the study area were collected...

  7. Does day length affect winter bird distribution? Testing the role of an elusive variable.

    Directory of Open Access Journals (Sweden)

    Luis M Carrascal

    Full Text Available Differences in day length may act as a critical factor in bird biology by introducing time constraints in energy acquisition during winter. Thus, differences in day length might operate as a main determinant of bird abundance along latitudinal gradients. This work examines the influence of day length on the abundance of wintering crested tits (Lophophanes cristatus in 26 localities of Spanish juniper (Juniperus thurifera dwarf woodlands (average height of 5 m located along a latitudinal gradient in the Spanish highlands, while controlling for the influence of food availability, minimum night temperature, habitat structure and landscape characteristics. Top regression models in the AIC framework explained 56% of variance in bird numbers. All models incorporated day length as the variable with the highest magnitude effect. Food availability also played an important role, although only the crop of ripe juniper fruits, but not arthropods, positively affected crested tit abundance. Differences in vegetation structure across localities had also a strong positive effect (average tree height and juniper tree density. Geographical variation in night temperature had no influence on crested tit distribution, despite the low winter temperatures reached in these dwarf forests. This paper demonstrates for the first time that winter bird abundance increases with day length after controlling for the effect of other environmental variables. Winter average difference in day length was only 10.5 minutes per day along the 1°47' latitudinal interval (190 km included in this study. This amount of time, which reaches 13.5 h accumulated throughout the winter season, appears to be large enough to affect the long-term energy budget of small passerines during winter and to shape the distribution of winter bird abundance under restrictive environmental conditions.

  8. Experimental approaches to test pesticide-treated seed avoidance by birds under a simulated diversification of food sources.

    Science.gov (United States)

    Lopez-Antia, Ana; Ortiz-Santaliestra, Manuel E; Mateo, Rafael

    2014-10-15

    Pesticide coated seeds are known to be potentially toxic for birds, but the risk of poisoning will depend on how likely the individuals are to consume them. To refine the risk assessment of coated seed consumption by birds we studied the consumption and avoidance of seeds treated with imidacloprid, thiram, maneb or rhodamine B under different scenarios of food unpredictability (diversity or changes in food sources). In a first set of experiments, we examined during four days the amount of ingested food by red-legged partridges (Alectoris rufa) when offered untreated seeds, treated seeds or both. In the latter case, we also assessed the effect of a daily interchange in the position of feeders containing treated and untreated food. A second experiment, conducted with imidacloprid only, consisted of offering, during 27 h, fixed overall amounts of treated and untreated food, equally distributed in a different number of feeders per pen (1, 2, 4 or 8 feeders of each type of food) in order to diversify food sources. All the tested pesticide-treated seeds were avoided in two-choice experiments, and imidacloprid and thiram were also avoided in one-choice experiments. We found that imidacloprid treated seeds were avoided, probably as a consequence of a conditioned aversion effect due to the post-ingestion distress. However, under a diversification of two-choice food sources with multiple feeders, imidacloprid-treated seeds were ingested by partridges at increasing amounts that can produce sublethal effects or even death. Thiram treated seeds were also initially avoided in one-choice experiment, but probably mediated by a sensory repellence that progressively decreased with time. Our results reveal that the risk of pesticide exposure in birds may increase by unpredictability of food resources or prolonged availability of coated seeds, so pesticide registration for seed coating should consider worst-case scenarios to avoid negative impacts on farmland birds.

  9. Maryland ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  10. Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

    Science.gov (United States)

    Muijres, Florian T; Johansson, L Christoffer; Bowlin, Melissa S; Winter, York; Hedenström, Anders

    2012-01-01

    Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate longer distances

  11. Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

    Directory of Open Access Journals (Sweden)

    Florian T Muijres

    Full Text Available Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate

  12. Importance of rapid testing to combat the global threat of bird flu.

    OpenAIRE

    Meijer, A.

    2006-01-01

    One of the important outcomes of the recently held meeting of the World Heatlh Organization (EHO), the Food and Agriculture Organization (FAO) of the United Nations, the World Organization of Animal Heath (OIE) and the World Bank in Genevan NOvember 7- 9, 2005, on the threat of avian inluenza A(H5N1), was that there is still a window of opporntunity ot minimize teh threat to both the animal and human populations at the source (the birds) through rapied reduction of the viraal burgen of A(H5N1...

  13. Development and field-testing of survey methods for a continental marsh bird monitoring program in North America

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Populations of many species of secretive marsh birds are thought to be declining in North America and several species are game birds in many states and provinces....

  14. Design of Test Wrapper Scan Chain Based on Differential Evolution

    Directory of Open Access Journals (Sweden)

    Aijun Zhu

    2013-08-01

    Full Text Available Integrated Circuit has entered the era of design of the IP-based SoC (System on Chip, which makes the IP core reuse become a key issue. SoC test wrapper design for scan chain is a NP Hard problem, we propose an algorithm based on Differential Evolution (DE to design wrapper scan chain. Through group’s mutation, crossover and selection operations, the design of test wrapper scan chain is achieved. Experimental verification is carried out according to the international standard benchmark ITC’02. The results show that the algorithm can obtain shorter longest wrapper scan chains, compared with other algorithms.

  15. Fault evolution-test dependency modeling for mechanical systems

    Institute of Scientific and Technical Information of China (English)

    Xiao-dong TAN; Jian-lu LUO; Qing LI; Bing LU; Jing QIU

    2015-01-01

    Tracking the process of fault growth in mechanical systems using a range of tests is important to avoid catastrophic failures. So, it is necessary to study the design for testability (DFT). In this paper, to improve the testability performance of me-chanical systems for tracking fault growth, a fault evolution-test dependency model (FETDM) is proposed to implement DFT. A testability analysis method that considers fault trackability and predictability is developed to quantify the testability performance of mechanical systems. Results from experiments on a centrifugal pump show that the proposed FETDM and testability analysis method can provide guidance to engineers to improve the testability level of mechanical systems.

  16. Screamy Bird

    DEFF Research Database (Denmark)

    Tarby, Sara; Cermak, Daniel

    2016-01-01

    Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016.......Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016....

  17. Physical Mapping and Refinement of the Painted Turtle Genome (Chrysemys picta) Inform Amniote Genome Evolution and Challenge Turtle-Bird Chromosomal Conservation.

    Science.gov (United States)

    Badenhorst, Daleen; Hillier, LaDeana W; Literman, Robert; Montiel, Eugenia Elisabet; Radhakrishnan, Srihari; Shen, Yingjia; Minx, Patrick; Janes, Daniel E; Warren, Wesley C; Edwards, Scott V; Valenzuela, Nicole

    2015-06-24

    Comparative genomics continues illuminating amniote genome evolution, but for many lineages our understanding remains incomplete. Here, we refine the assembly (CPI 3.0.3 NCBI AHGY00000000.2) and develop a cytogenetic map of the painted turtle (Chrysemys picta-CPI) genome, the first in turtles and in vertebrates with temperature-dependent sex determination. A comparison of turtle genomes with those of chicken, selected nonavian reptiles, and human revealed shared and novel genomic features, such as numerous chromosomal rearrangements. The largest conserved syntenic blocks between birds and turtles exist in four macrochromosomes, whereas rearrangements were evident in these and other chromosomes, disproving that turtles and birds retain fully conserved macrochromosomes for greater than 300 Myr. C-banding revealed large heterochromatic blocks in the centromeric region of only few chromosomes. The nucleolar-organizing region (NOR) mapped to a single CPI microchromosome, whereas in some turtles and lizards the NOR maps to nonhomologous sex-chromosomes, thus revealing independent translocations of the NOR in various reptilian lineages. There was no evidence for recent chromosomal fusions as interstitial telomeric-DNA was absent. Some repeat elements (CR1-like, Gypsy) were enriched in the centromeres of five chromosomes, whereas others were widespread in the CPI genome. Bacterial artificial chromosome (BAC) clones were hybridized to 18 of the 25 CPI chromosomes and anchored to a G-banded ideogram. Several CPI sex-determining genes mapped to five chromosomes, and homology was detected between yet other CPI autosomes and the globally nonhomologous sex chromosomes of chicken, other turtles, and squamates, underscoring the independent evolution of vertebrate sex-determining mechanisms.

  18. Detection of antibodies against H5 and H7 strains in birds: evaluation of influenza pseudovirus particle neutralization tests

    Directory of Open Access Journals (Sweden)

    Sofie Wallerström

    2014-01-01

    Full Text Available Introduction: Avian influenza viruses circulate in bird populations, and it is important to maintain and uphold our knowledge of the viral strains that are currently of interest in this context. Here, we describe the use of hemagglutinin-pseudotype retroviruses based on highly pathogenic influenza viruses for the screening of avian sera for influenza A antibodies. Our aim was also to determine whether the pseudovirus neutralization tests that we assessed were sensitive and simple to use compared to the traditional methods, including hemagglutination inhibition assays and microneutralization tests. Material and methods: H5 and H7 pseudovirus neutralization tests were evaluated by using serum from infected rabbits. Subsequently, the assays were further investigated using a panel of serum samples from avian species. The panel contained samples that were seropositive for five different hemagglutinin subtypes as well as influenza A seronegative samples. Results and discussion: The results suggest that the pseudovirus neutralization test is an alternative to hemagglutination inhibition assays, as we observed comparable titers to those of both standard microneutralizations assays as well as hemagglutinin inhibition assays. When evaluated by a panel of avian sera, the method also showed its capability to recognize antibodies directed toward low-pathogenic H5 and H7. Hence, we conclude that it is possible to use pseudoviruses based on highly pathogenic avian influenza viruses to screen avian sera for antibodies directed against influenza A subtypes H5 and H7.

  19. THE EARLY BIRD CATCHES THE WORM : EARLY COST-EFFECTIVENESS ANALYSIS OF NEW MEDICAL TESTS

    NARCIS (Netherlands)

    Buisman, Leander R; Rutten-van Mölken, Maureen P M H; Postmus, Douwe; Luime, Jolanda J; Uyl-de Groot, Carin A; Redekop, William K

    2016-01-01

    OBJECTIVES: There is little specific guidance on performing an early cost-effectiveness analysis (CEA) of medical tests. We developed a framework with general steps and applied it to two cases. METHODS: Step 1 is to narrow down the scope of analysis by defining the test's application, target populat

  20. Testing optimality with experimental evolution: lysis time in a bacteriophage.

    Science.gov (United States)

    Heineman, Richard H; Bull, James J

    2007-07-01

    Optimality models collapse the vagaries of genetics into simple trade-offs to calculate phenotypes expected to evolve by natural selection. Optimality approaches are commonly criticized for this neglect of genetic details, but resolution of this disagreement has been difficult. The importance of genetic details may be tested by experimental evolution of a trait for which an optimality model exists and in which genetic details can be studied. Here we evolved lysis time in bacteriophage T7, a virus of Escherichia coli. Lysis time is equivalent to the age of reproduction in an organism that reproduces once and then dies. Delaying lysis increases the number of offspring but slows generation time, and this trade-off renders the optimum sensitive to environmental conditions: earlier lysis is favored when bacterial hosts are dense, later lysis is favored when hosts are sparse. In experimental adaptations, T7 evolved close to the optimum in conditions favoring early lysis but not in conditions favoring late lysis. One of the late lysis adaptations exhibited no detectable phenotypic evolution despite genetic evolution; the other evolved only partly toward the expected optimum. Overall, the lysis time of the adapted phages remained closer to their starting values than predicted by the model. From the perspective of the optimality model, the experimental conditions were expected to select changes only along the postulated trade-off, but a trait outside the trade-off evolved as well. Evidence suggests that the model's failure ultimately stems from a violation of the trade-off, rather than a paucity of mutations.

  1. Angels, Demons, Birds and Dinosaurs

    DEFF Research Database (Denmark)

    Ries, Christopher Jacob

    2010-01-01

    of birds, setting the international agenda for research in bird evolution for the next 40 years. In Denmark, however, Heilmann's highly original work was generally ignored or even ridiculed by zoologists. This article demonstrates how Heilmann's artistic abilities played an important role in securing him...... international renown as a palaeontologist, while at the same time his lack of scientific credentials led to his complete isolation from the Danish zoological establishment. And it suggests that Heilmann's unyielding efforts to solve the riddle of bird evolution in the borderland between art and science...

  2. Development and evaluation of an online CO(2) evolution test and a multicomponent biodegradation test system.

    Science.gov (United States)

    Strotmann, Uwe; Reuschenbach, Peter; Schwarz, Helmut; Pagga, Udo

    2004-08-01

    Well-established biodegradation tests use biogenously evolved carbon dioxide (CO(2)) as an analytical parameter to determine the ultimate biodegradability of substances. A newly developed analytical technique based on the continuous online measurement of conductivity showed its suitability over other techniques. It could be demonstrated that the method met all criteria of established biodegradation tests, gave continuous biodegradation curves, and was more reliable than other tests. In parallel experiments, only small variations in the biodegradation pattern occurred. When comparing the new online CO(2) method with existing CO(2) evolution tests, growth rates and lag periods were similar and only the final degree of biodegradation of aniline was slightly lower. A further test development was the unification and parallel measurement of all three important summary parameters for biodegradation--i.e., CO(2) evolution, determination of the biochemical oxygen demand (BOD), and removal of dissolved organic carbon (DOC)--in a multicomponent biodegradation test system (MCBTS). The practicability of this test method was demonstrated with aniline. This test system had advantages for poorly water-soluble and highly volatile compounds and allowed the determination of the carbon fraction integrated into biomass (heterotrophic yield). The integrated online measurements of CO(2) and BOD systems produced continuous degradation curves, which better met the stringent criteria of ready biodegradability (60% biodegradation in a 10-day window). Furthermore the data could be used to calculate maximal growth rates for the modeling of biodegradation processes.

  3. Development and Evaluation of an Online CO2 Evolution Test and a Multicomponent Biodegradation Test System

    Science.gov (United States)

    Strotmann, Uwe; Reuschenbach, Peter; Schwarz, Helmut; Pagga, Udo

    2004-01-01

    Well-established biodegradation tests use biogenously evolved carbon dioxide (CO2) as an analytical parameter to determine the ultimate biodegradability of substances. A newly developed analytical technique based on the continuous online measurement of conductivity showed its suitability over other techniques. It could be demonstrated that the method met all criteria of established biodegradation tests, gave continuous biodegradation curves, and was more reliable than other tests. In parallel experiments, only small variations in the biodegradation pattern occurred. When comparing the new online CO2 method with existing CO2 evolution tests, growth rates and lag periods were similar and only the final degree of biodegradation of aniline was slightly lower. A further test development was the unification and parallel measurement of all three important summary parameters for biodegradation—i.e., CO2 evolution, determination of the biochemical oxygen demand (BOD), and removal of dissolved organic carbon (DOC)—in a multicomponent biodegradation test system (MCBTS). The practicability of this test method was demonstrated with aniline. This test system had advantages for poorly water-soluble and highly volatile compounds and allowed the determination of the carbon fraction integrated into biomass (heterotrophic yield). The integrated online measurements of CO2 and BOD systems produced continuous degradation curves, which better met the stringent criteria of ready biodegradability (60% biodegradation in a 10-day window). Furthermore the data could be used to calculate maximal growth rates for the modeling of biodegradation processes. PMID:15294794

  4. Whole genome identification, phylogeny and evolution of the cytochrome P450 family 2 (CYP2) sub-families in birds

    DEFF Research Database (Denmark)

    Almeida, Daniela; Maldonado, Emanuel; Khan, Imran

    2016-01-01

    The cytochrome P450 (CYP) superfamily defends organisms from endogenous and noxious environmental compounds, and thus is crucial for survival. However, beyond mammals the molecular evolution of CYP2 subfamilies is poorly understood. Here, we characterized the CYP2 family across 48 novel avian whole...

  5. Bird Vision System

    Science.gov (United States)

    2008-01-01

    The Bird Vision system is a multicamera photogrammerty software application that runs on a Microsoft Windows XP platform and was developed at Kennedy Space Center by ASRC Aerospace. This software system collects data about the locations of birds within a volume centered on the Space Shuttle and transmits it in real time to the laptop computer of a test director in the Launch Control Center (LCC) Firing Room.

  6. Bird guard

    Science.gov (United States)

    Fairchild, Dana M.

    2010-03-02

    The bird guard provides a device to protect electrical insulators comprising a central shaft; a clamp attached to an end of the shaft to secure the device to a transmission tower; a top and bottom cover to shield transmission tower insulators; and bearings to allow the guard to rotate in order to frighten birds away from the insulators.

  7. Testing the junk-food hypothesis on marine birds: Effects of prey type on growth and development

    Science.gov (United States)

    Romano, Marc D.; Piatt, J.F.; Roby, D.D.

    2006-01-01

    The junk-food hypothesis attributes declines in productivity of marine birds and mammals to changes in the species of prey they consume and corresponding differences in nutritional quality of those prey. To test this hypothesis nestling Black-legged Kittiwakes (Rissa tridactyla) and Tufted Puffins (Fratercula cirrhata) were raised in captivity under controlled conditions to determine whether the type and quality of fish consumed by young seabirds constrains their growth and development. Some nestlings were fed rations of Capelin (Mallotus villosus), Herring (Clupea pallasi) or Sand Lance (Ammodytes hexapterus) and their growth was compared with nestlings raised on equal biomass rations of Walleye Pollock (Theragra chalcograma). Nestlings fed rations of herring, sand lance, or capelin experienced higher growth increments than nestlings fed pollock. The energy density of forage fish fed to nestlings had a marked effect on growth increments and could be expected to have an effect on pre- and post-fledging survival of nestlings in the wild. These results provide empirical support for the junk-food hypothesis.

  8. SWS2 visual pigment evolution as a test of historically contingent patterns of plumage color evolution in warblers.

    Science.gov (United States)

    Bloch, Natasha I; Morrow, James M; Chang, Belinda S W; Price, Trevor D

    2015-02-01

    Distantly related clades that occupy similar environments may differ due to the lasting imprint of their ancestors-historical contingency. The New World warblers (Parulidae) and Old World warblers (Phylloscopidae) are ecologically similar clades that differ strikingly in plumage coloration. We studied genetic and functional evolution of the short-wavelength-sensitive visual pigments (SWS2 and SWS1) to ask if altered color perception could contribute to the plumage color differences between clades. We show SWS2 is short-wavelength shifted in birds that occupy open environments, such as finches, compared to those in closed environments, including warblers. Phylogenetic reconstructions indicate New World warblers were derived from a finch-like form that colonized from the Old World 15-20 Ma. During this process, the SWS2 gene accumulated six substitutions in branches leading to New World warblers, inviting the hypothesis that passage through a finch-like ancestor resulted in SWS2 evolution. In fact, we show spectral tuning remained similar across warblers as well as the finch ancestor. Results reject the hypothesis of historical contingency based on opsin spectral tuning, but point to evolution of other aspects of visual pigment function. Using the approach outlined here, historical contingency becomes a generally testable theory in systems where genotype and phenotype can be connected.

  9. Whole genome identification, phylogeny and evolution of the cytochrome P450 family 2 (CYP2) sub-families in birds

    DEFF Research Database (Denmark)

    Almeida, Daniela; Maldonado, Emanuel; Khan, Imran;

    2016-01-01

    The cytochrome P450 (CYP) superfamily defends organisms from endogenous and noxious environmental compounds, and thus is crucial for survival. However, beyond mammals the molecular evolution of CYP2 subfamilies is poorly understood. Here, we characterized the CYP2 family across 48 novel avian whole......0, SRS2_SRS3 and SRS3.1) and heme binding areas that influence CYP2 structure and function of functional importance as under significant positive selection. Some of the positively selected sites in avian CYP2D are located within the same SRS1 region that was previously linked with the metabolism...

  10. Talking Birds

    Institute of Scientific and Technical Information of China (English)

    海文

    2005-01-01

    Many students of Englishthink thatlearning a new languageis very difficult.N ow think howdifficultitis to learn English whenyour brain is only the size of abird's brain。That is what som ebirds can do.M any different kinds of birdscan copy the sounds of lan-guage.A frican gray parrots are thebirds bestknown for this.Every D ecem ber in London,the N ationalCage and A viary BirdShow tries to find the best“talkbird in the world.O ne bird nam edPrudle stood outam ong the“talk-ing birds by winning this prizeevery...

  11. Global avian influenza surveillance in wild birds: a strategy to capture viral diversity.

    Science.gov (United States)

    Machalaba, Catherine C; Elwood, Sarah E; Forcella, Simona; Smith, Kristine M; Hamilton, Keith; Jebara, Karim B; Swayne, David E; Webby, Richard J; Mumford, Elizabeth; Mazet, Jonna A K; Gaidet, Nicolas; Daszak, Peter; Karesh, William B

    2015-04-01

    Wild birds play a major role in the evolution, maintenance, and spread of avian influenza viruses. However, surveillance for these viruses in wild birds is sporadic, geographically biased, and often limited to the last outbreak virus. To identify opportunities to optimize wild bird surveillance for understanding viral diversity, we reviewed responses to a World Organisation for Animal Health-administered survey, government reports to this organization, articles on Web of Knowledge, and the Influenza Research Database. At least 119 countries conducted avian influenza virus surveillance in wild birds during 2008-2013, but coordination and standardization was lacking among surveillance efforts, and most focused on limited subsets of influenza viruses. Given high financial and public health burdens of recent avian influenza outbreaks, we call for sustained, cost-effective investments in locations with high avian influenza diversity in wild birds and efforts to promote standardized sampling, testing, and reporting methods, including full-genome sequencing and sharing of isolates with the scientific community.

  12. 机翼前缘结构鸟撞仿真分析与试验验证%Bird Strike Simulation and Test Validation for Wing Leading Edge

    Institute of Scientific and Technical Information of China (English)

    王会利

    2015-01-01

    Bird strike simulation by using instantaneous non-linear FEM is an important work in the process of the bird strike design.In this paper, the bird strike simulation of four different wing leading edge structures with FE software PAM-CRASH is presented, the optimum structure was chosen in four structures.Meanwhile, the bird strike test is done to the optimum structure, the strain curves and clash-force curves were compared with simulation results, the curvilinear trends were in concordance, which indicate experimental results were reasonable, and provided the reference for the design and promotion of bird-strike resistance of wing leading edge.%采用瞬态非线性有限元方法进行鸟撞仿真已成为鸟撞设计工作的主要内容。运用PAM-CRASH软件对四种不同前缘结构进行了仿真计算分析,选出了四种结构中的最优结构。同时,对选出的最优前缘结构进行了鸟撞试验,将试验得到的应变曲线和撞击力曲线与仿真结果进行对比,曲线趋势基本一致,说明仿真计算结果是合理的,为前缘结构的抗鸟撞设计及改型提供了参考。

  13. Hawaii ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for endangered waterbirds and passerine birds, migratory shorebirds and waterfowl, gulls and terns,...

  14. Grassland Evolution Under Soil Degradation: Numerical Simulation and Test

    Institute of Scientific and Technical Information of China (English)

    QI Xiang-Zhen; LIN Zhen-Shan

    2005-01-01

    Both theoretical and field observations were examined to study the close relationship between soil degeneration and the evolution of grassland vegetation. A general n-species model of equal competition under different degrees of soil degradation was applied to field data in order to probe the dynamic processes and mechanisms of vegetation evolution due to the effects of the soil's ecological deterioration on grassland vegetation. Comparisons were made between the theoretical results and the practical surveys with satisfactory results.

  15. Restrain of birds with bottles of polyethylene terephthalate, tested in red-browed from the Atlantic Forest

    Directory of Open Access Journals (Sweden)

    M.A.F. Bianchi

    2016-02-01

    Full Text Available In wild animals, containment is the moment of greatest stress caused by the investigator to the animal due to its natural resistance to the moment of capture, handling, containment and transport, attitudes frankly contrary to his nature. In birds, the restraint must meet certain criteria in order to control the animal's movements, avoiding trauma at the same time that you need to keep your breathing amplitude. The high risk of death during the restraint of these animals raised the need to design a device, from bottles of poly ethylene terephthalate (PET, for containing parrots-browed Amazon (Amazona rhodocorytha, a parrot endemic to the Atlantic Forest in southeastern Brazil, and endangered with extinction, which allowed the observation of respiration, the reduction of handling time of birds for collection of biological material, and consequent reduction of stress and risk of death during the evaluation of several biological data and health of the bird. The PET bottle container can be used as a model for any bird, provided it suits the size of the animal.

  16. Birds as predators in tropical agroforestry systems.

    Science.gov (United States)

    Van Bael, Sunshine A; Philpott, Stacy M; Greenberg, Russell; Bichier, Peter; Barber, Nicholas A; Mooney, Kailen A; Gruner, Daniel S

    2008-04-01

    Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a good starting point for understanding when and where we can expect predation by birds to be important. We analyze data from bird exclosure studies in forests and agroforestry systems to ask whether birds consistently reduce their arthropod prey base and whether bird predation differs between forests and agroforestry systems. Further, we focus on agroforestry systems to ask whether the magnitude of bird predation (1) differs between canopy trees and understory plants, (2) differs when migratory birds are present or absent, and (3) correlates with bird abundance and diversity. We found that, across all studies, birds reduce all arthropods, herbivores, carnivores, and plant damage. We observed no difference in the magnitude of bird effects between agroforestry systems and forests despite simplified habitat structure and plant diversity in agroforests. Within agroforestry systems, bird reduction of arthropods was greater in the canopy than the crop layer. Top-down effects of bird predation were especially strong during censuses when migratory birds were present in agroforestry systems. Importantly, the diversity of the predator assemblage correlated with the magnitude of predator effects; where the diversity of birds, especially migratory birds, was greater, birds reduced arthropod densities to a greater extent. We outline potential mechanisms for relationships between bird predator, insect prey, and habitat characteristics, and we suggest future studies using tropical agroforests as a model system to further test these areas of ecological theory.

  17. Columbia River ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, diving birds, seabirds, passerine birds, gulls, and terns in...

  18. Western Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  19. Linkages between the life-history evolution of tropical and temperate birds and the resistance of cultured skin fibroblasts to oxidative and non-oxidative chemical injury

    OpenAIRE

    Jimenez, Ana Gabriela; Harper, James M.; Simon A. Queenborough; Williams, Joseph B.

    2013-01-01

    A fundamental challenge facing physiological ecologists is to understand how variation in life history at the whole-organism level might be linked to cellular function. Thus, because tropical birds have higher annual survival and lower rates of metabolism, we hypothesized that cells from tropical species would have greater cellular resistance to chemical injury than cells from temperate species. We cultured dermal fibroblasts from 26 tropical and 26 temperate species of birds and examined cel...

  20. Single-locus tests of microsatellite evolution : Multi-step mutations and constraints on allele size

    NARCIS (Netherlands)

    Nielsen, R; Palsboll, PJ

    1999-01-01

    We evaluate some common simulation procedures as well as a recently developed likelihood method used for testing hypotheses regarding microsatellite evolution. Results from simulated data revealed that the tests for the detection of multi-step mutations in general have some power, whereas tests for

  1. The Max Launch Abort System - Concept, Flight Test, and Evolution

    Science.gov (United States)

    Gilbert, Michael G.

    2014-01-01

    The NASA Engineering and Safety Center (NESC) is an independent engineering analysis and test organization providing support across the range of NASA programs. In 2007 NASA was developing the launch escape system for the Orion spacecraft that was evolved from the traditional tower-configuration escape systems used for the historic Mercury and Apollo spacecraft. The NESC was tasked, as a programmatic risk-reduction effort to develop and flight test an alternative to the Orion baseline escape system concept. This project became known as the Max Launch Abort System (MLAS), named in honor of Maxime Faget, the developer of the original Mercury escape system. Over the course of approximately two years the NESC performed conceptual and tradeoff analyses, designed and built full-scale flight test hardware, and conducted a flight test demonstration in July 2009. Since the flight test, the NESC has continued to further develop and refine the MLAS concept.

  2. BIRD FLU (AVIAN INFLUENZA)

    OpenAIRE

    Ali ACAR; Bulent BESIRBELLIOÐLU

    2005-01-01

    Avian influenza (bird flu) is a contagious disease of animals caused by influenza A viruses. These flu viruses occur naturally among birds. Actually, humans are not infected by bird flu viruses.. However, during an outbreak of bird flu among poultry, there is a possible risk to people who have contact infect birds or surface that have been contaminated with excreations from infected birds. Symptoms of bird flu in humans have ranged from typical flu-like symptoms to eye infections, pneumonia, ...

  3. Year-round resource defence and the evolution of male and female song in suboscine birds: social armaments are mutual ornaments.

    Science.gov (United States)

    Tobias, J A; Gamarra-Toledo, V; García-Olaechea, D; Pulgarín, P C; Seddon, N

    2011-10-01

    The evolution of sexually monomorphic (i.e. mutual) ornamentation has attracted growing attention as a 'blind-spot' in evolutionary biology. The popular consensus is that female ornaments are subject to the same modes of sexual selection as males: intrasexual competition and mate choice. However, it remains unclear how these forces interact within and between sexes, or whether they fully capture selection on female traits. One possibility is that the 'armament-ornament' model - which proposes that traits used primarily in male-male contests are also co-opted by females as indicators of male quality - can be extended to explain signal evolution in both sexes. We examine this idea by testing the function of acoustic signals in two species of duetting antbirds. Behavioural observations and playback experiments suggest that male and female songs function primarily as armaments in competitive interactions. Removal experiments reveal that song is also a classic ornament used by unpaired males and females to advertise for mates. These results indicate that 'armament-ornament' processes may operate in reciprocal format, potentially explaining widespread mutual ornamentation in species with elevated intrasexual competition for resources. In addition, given that songs mediate competition between species outside the breeding season, our findings suggest that processes shaping monomorphic ornaments extend beyond the traditional definitions of sexual selection and are best understood in the broader framework of social selection.

  4. Banishment in Public Housing: Testing an Evolution of Broken Windows

    Directory of Open Access Journals (Sweden)

    Jose Torres

    2016-10-01

    Full Text Available Banishment policies grant police the authority to formally ban individuals from entering public housing and arrest them for trespassing if they violate the ban. Despite its widespread use and the social consequences resulting from it, an empirical evaluation of the effectiveness of banishment has not been performed. Understanding banishment enforcement is an evolution of broken windows policing, this study explores how effective bans are at reducing crime in public housing. We analyze crime data, spanning the years 2001–2012, from six public housing communities and 13 surrounding communities in one southeastern U.S. city. Using Arellano-Bond dynamic panel models, we investigate whether or not issuing bans predicts reductions in property and violent crimes as well as increases in drug and trespass arrests in public housing. We find that this brand of broken windows policing does reduce crime, albeit relatively small reductions and only for property crime, while resulting in an increase in trespass arrests. Given our findings that these policies have only a modest impact on property crime, yet produce relatively larger increases in arrests for minor offenses in communities of color, and ultimately have no significant impact on violent crime, it will be important for police, communities, and policy makers to discuss whether the returns are worth the potential costs.

  5. Game Birds of Colorado.

    Science.gov (United States)

    Colorado State Div. of Wildlife, Denver.

    This booklet is intended to familiarize the reader with game birds typical of Colorado. Discussions in English and Spanish are presented. Discussions cover the management of game birds, individual game bird species, and endangered species of birds related to game birds. (RE)

  6. Diving birds

    Science.gov (United States)

    Clanet, Christophe; Masson, Lucien; McKinley, Gareth; Cohen, Robert; Ecole polytechnique Collaboration; MIT Collaboration

    2015-11-01

    Many seabirds (gannets, pelicans, gulls, albatrosses) dive into water at high speeds (25 m/s) in order to capture underwater preys. Diving depths of 20 body lengths are reported in the literature. This value is much larger than the one achieved by men, which is of the order of 5. We study this difference by comparing the impact of slender vs bluff bodies. We show that, contrary to bluff bodies, the penetration depth of slender bodies presents a maximum value for a specific impact velocity that we connect to the velocity of diving birds.

  7. Nonlinear evolution equations and Painlevé test

    CERN Document Server

    Steeb, Willi-Hans

    1988-01-01

    This book is an edited version of lectures given by the authors at a seminar at the Rand Afrikaans University. It gives a survey on the Painlevé test, Painlevé property and integrability. Both ordinary differential equations and partial differential equations are considered.

  8. Birth of the Astronomy Diagnostic Test: Prototest Evolution

    Science.gov (United States)

    Zeilik, M.

    2001-12-01

    In 1992, with funding by the National Science Foundation, a multidisciplinary research team at the University of New Mexico accreted to transform a "traditional Astro 101" course into a conceptually-oriented one. The team consisted of people from astronomy, cognitive psychology, and education. Our aim was to improve the learning environment in a large "lecture" course based on current cognitive models of adult learning. We demanded that our effort be research-based, but found little in the literature to assist us; for example, no field-tested assessment tools that would measure appropiate outcomes had been developed in higher education. From prior research at lower grades, we saw the need of a valid and reliable "misconceptions" test. We also desired to tap into higher level conceptual learning, and so developed concept map assessments to measure acquisition of the "Big Picture" in astronomy. These "misconceptions measures" were protoversions of the Astronomy Diagnostic Test (ADT) that gained in structure and usefulness over four semesters involving hundreds of students. I will outline our methodology to develop the ADT in a bootstrap way, its basis as a learning tool, and its correlation with other assessments (especially the concept maps) and achievement in the UNM "Astro 101" course. This work was supported in part by NSF DUE grants 9253983 and 9981155.

  9. Bird Flu (Avian Influenza)

    Science.gov (United States)

    ... for the treatment of H7N9 bird flu. Bird flu vaccine The Food and Drug Administration has approved one ... continue to work on other types of bird flu vaccines. Recommendations for travelers If you're traveling to ...

  10. Migration of birds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the migration of birds. Topics covered include why birds migrate, when birds migrate, speed, altitude, courses, distance, major flyways and...

  11. Testing bedrock incision models: Holocene channel evolution, High Cascades, Oregon

    Science.gov (United States)

    Sweeney, K. E.; Roering, J. J.; Fonstad, M. A.

    2013-12-01

    and previous studies of Collier Glacier give a likely range of values for grain size, sediment supply and water discharge; we use a 1D energy equation to calculate channel shear stress. Our results from the stream power model show that the incision patterns in both gorges are not well predicted by a single value of the stream power coefficient K, but can be matched relatively well by decreasing K by a factor of two in the lower gorge. This result implies lower erosional efficacy in the lower gorge but does not discriminate among the many mechanisms that may lead to a lower K (asynchronous incision, discharge variability, etc.). Using the mechanistic formulation of the saltation-abrasion model, we explore the implications of factors that may control incision along the channel such as (1) rare, high-magnitude outburst floods, (2) asynchronous incision of the two gorges and (3) hydraulic and sediment transport relationships specific to steep mountain streams (e.g., slope-dependent critical Shields stress). Our initial runs of the saltation-abrasion models underpredict the magnitude of incision, given a reasonable range of inputs. Hence, though the morphology of the gorges indicates that some abrasion has occurred, we suggest that erosion due to plucking also played a significant role in channel evolution.

  12. Green Light for Nocturnally Migrating Birds

    Directory of Open Access Journals (Sweden)

    Hanneke Poot

    2008-12-01

    Laboratory experiments have shown the magnetic compass to be wavelength dependent: migratory birds require light from the blue-green part of the spectrum for magnetic compass orientation, whereas red light (visible long-wavelength disrupts magnetic orientation. We designed a field study to test if and how changing light color influenced migrating birds under field conditions. We found that nocturnally migrating birds were disoriented and attracted by red and white light (containing visible long-wavelength radiation, whereas they were clearly less disoriented by blue and green light (containing less or no visible long-wavelength radiation. This was especially the case on overcast nights. Our results clearly open perspective for the development of bird-friendly artificial lighting by manipulating wavelength characteristics. Preliminary results with an experimentally developed bird-friendly light source on an offshore platform are promising. What needs to be investigated is the impact of bird-friendly light on other organisms than birds.

  13. Testing for HER2 in Breast Cancer: A Continuing Evolution

    Directory of Open Access Journals (Sweden)

    Sejal Shah

    2011-01-01

    Full Text Available Human epidermal growth factor receptor 2 (HER2 is an important prognostic and predictive factor in breast cancer. HER2 is overexpressed in approximately 15%–20% of invasive breast carcinomas and is associated with earlier recurrence, shortened disease free survival, and poor prognosis. Trastuzumab (Herceptin a “humanized” monoclonal antibody targets the extracellular domain of HER2 and is widely used in the management of HER2 positive breast cancers. Accurate assessment of HER2 is thus critical in the management of breast cancer. The aim of this paper is to present a comprehensive review of HER2 with reference to its discovery and biology, clinical significance, prognostic value, targeted therapy, current and new testing modalities, and the interpretation guidelines and pitfalls.

  14. MASSCLEAN - MASSive CLuster Evolution and ANalysis Package - Description and Tests

    CERN Document Server

    Popescu, Bogdan

    2008-01-01

    We present MASSCLEAN, a new, sophisticated and robust stellar cluster image and photometry simulation package. This package is able to create color-magnitude diagrams and standard FITS images in any of the traditional optical and near-infrared bands based on cluster characteristics input by the user, including but not limited to distance, age, mass, radius and extinction. At the limit of very distant, unresolved clusters, we have checked the integrated colors created in MASSCLEAN against those from other single stellar population models with consistent results. We have also tested models which provide a reasonable estimate of the field star contamination in images and color-magnitude diagrams. We demonstrate the package by simulating images and color-magnitude diagrams of well known massive Milky Way clusters and compare their appearance to real data. Because the algorithm populates the cluster with a discrete number of tenable stars, it can be used as part of a Monte Carlo Method to derive the probabilistic ...

  15. The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents

    Directory of Open Access Journals (Sweden)

    T. Alexander Dececchi

    2016-07-01

    Full Text Available Background: Powered flight is implicated as a major driver for the success of birds. Here we examine the effectiveness of three hypothesized pathways for the evolution of the flight stroke, the forelimb motion that powers aerial locomotion, in a terrestrial setting across a range of stem and basal avians: flap running, Wing Assisted Incline Running (WAIR, and wing-assisted leaping. Methods: Using biomechanical mathematical models based on known aerodynamic principals and in vivo experiments and ground truthed using extant avians we seek to test if an incipient flight stroke may have contributed sufficient force to permit flap running, WAIR, or leaping takeoff along the phylogenetic lineage from Coelurosauria to birds. Results: None of these behaviours were found to meet the biomechanical threshold requirements before Paraves. Neither was there a continuous trend of refinement for any of these biomechanical performances across phylogeny nor a signal of universal applicability near the origin of birds. None of these flap-based locomotory models appear to have been a major influence on pre-flight character acquisition such as pennaceous feathers, suggesting non-locomotory behaviours, and less stringent locomotory behaviours such as balancing and braking, played a role in the evolution of the maniraptoran wing and nascent flight stroke. We find no support for widespread prevalence of WAIR in non-avian theropods, but can’t reject its presence in large winged, small-bodied taxa like Microraptor and Archaeopteryx. Discussion: Using our first principles approach we find that “near flight” locomotor behaviors are most sensitive to wing area, and that non-locomotory related selection regimes likely expanded wing area well before WAIR and other such behaviors were possible in derived avians. These results suggest that investigations of the drivers for wing expansion and feather elongation in theropods need not be intrinsically linked to locomotory

  16. How to Make a Bird Skull: Major Transitions in the Evolution of the Avian Cranium, Paedomorphosis, and the Beak as a Surrogate Hand.

    Science.gov (United States)

    Bhullar, Bhart-Anjan S; Hanson, Michael; Fabbri, Matteo; Pritchard, Adam; Bever, Gabe S; Hoffman, Eva

    2016-09-01

    The avian skull is distinctive in its construction and in its function. Much of bird anatomical variety is expressed in the beak; but the beak itself, largely formed of the premaxillary bone, is set upon a shortened face and a bulbous, enlarged braincase. Here, we use original anatomical observations and reconstructions to describe the overall form of the avian skull in a larger context and to provide a general account of the evolutionary transformation from the early dinosaur skull-the skull of an archosaurian macropredator-to that of modern birds. Facial shortening, the enlargement of the braincase around an enlarged brain (with consequential reduction of circumorbital elements and the adductor chamber), and general thinning and looser articulation of bones are trends. Many of these owe to juvenilization or paedomorphosis, something that is abundantly evident from comparison of a juvenile early theropod (Coelophysis) to early avialans like Archaeopteryx Near the avian crown, the premaxilla becomes dramatically enlarged and integrated into the characteristic mobile kinetic system of birds. We posit that this addition of a large element onto the skull may be biomechanically feasible only because of the paedomorphic shortening of the face; and kinesis of the beak only because of the paedomorphic thinning of the bones and loosening of articulations, as played out in reverse during the maturation of Coelophysis Finally, the beak itself becomes elaborated as the hands are integrated into the wing. There are structural, kinematic, and neurological similarities between avian pecking and primate grasping. The ability to precision-select high-quality food against a complex but depauperate background may have permitted crown birds to survive the end-Cretaceous cataclysm by feeding on insects, seeds, and other detritus after the collapse of higher trophic levels in the food web.

  17. The evolution of genomic imprinting: theories, predictions and empirical tests.

    Science.gov (United States)

    Patten, M M; Ross, L; Curley, J P; Queller, D C; Bonduriansky, R; Wolf, J B

    2014-08-01

    The epigenetic phenomenon of genomic imprinting has motivated the development of numerous theories for its evolutionary origins and genomic distribution. In this review, we examine the three theories that have best withstood theoretical and empirical scrutiny. These are: Haig and colleagues' kinship theory; Day and Bonduriansky's sexual antagonism theory; and Wolf and Hager's maternal-offspring coadaptation theory. These theories have fundamentally different perspectives on the adaptive significance of imprinting. The kinship theory views imprinting as a mechanism to change gene dosage, with imprinting evolving because of the differential effect that gene dosage has on the fitness of matrilineal and patrilineal relatives. The sexual antagonism and maternal-offspring coadaptation theories view genomic imprinting as a mechanism to modify the resemblance of an individual to its two parents, with imprinting evolving to increase the probability of expressing the fitter of the two alleles at a locus. In an effort to stimulate further empirical work on the topic, we carefully detail the logic and assumptions of all three theories, clarify the specific predictions of each and suggest tests to discriminate between these alternative theories for why particular genes are imprinted.

  18. Testing Convergence Versus History: Convergence Dominates Phenotypic Evolution for over 150 Million Years in Frogs.

    Science.gov (United States)

    Moen, Daniel S; Morlon, Hélène; Wiens, John J

    2016-01-01

    Striking evolutionary convergence can lead to similar sets of species in different locations, such as in cichlid fishes and Anolis lizards, and suggests that evolution can be repeatable and predictable across clades. Yet, most examples of convergence involve relatively small temporal and/or spatial scales. Some authors have speculated that at larger scales (e.g., across continents), differing evolutionary histories will prevent convergence. However, few studies have compared the contrasting roles of convergence and history, and none have done so at large scales. Here we develop a two-part approach to test the scale over which convergence can occur, comparing the relative importance of convergence and history in macroevolution using phylogenetic models of adaptive evolution. We apply this approach to data from morphology, ecology, and phylogeny from 167 species of anuran amphibians (frogs) from 10 local sites across the world, spanning ~160 myr of evolution. Mapping ecology on the phylogeny revealed that similar microhabitat specialists (e.g., aquatic, arboreal) have evolved repeatedly across clades and regions, producing many evolutionary replicates for testing for morphological convergence. By comparing morphological optima for clades and microhabitat types (our first test), we find that convergence associated with microhabitat use dominates frog morphological evolution, producing recurrent ecomorphs that together encompass all sampled species in each community in each region. However, our second test, which examines whether and how much species differ from their inferred optima, shows that convergence is incomplete: that is, phenotypes of most species are still somewhat distant from the estimated optimum for each microhabitat, seemingly because of insufficient time for more complete adaptation (an effect of history). Yet, these effects of history are related to past ecologies, and not clade membership. Overall, our study elucidates the dominant drivers of

  19. A Thankful Bird

    Institute of Scientific and Technical Information of China (English)

    颜巧玲

    2002-01-01

    One day, I was playing in the woods when I saw a bird standing on a tree branch in the rain. “Poor bird, I thought, ”He has no home. “When I got home, I set down to make a house for the bird so that the bird would not catch rain any longer.

  20. Experimental evolution of an RNA virus in wild birds: evidence for host-dependent impacts on population structure and competitive fitness.

    Directory of Open Access Journals (Sweden)

    Nathan D Grubaugh

    2015-05-01

    Full Text Available Within hosts, RNA viruses form populations that are genetically and phenotypically complex. Heterogeneity in RNA virus genomes arises due to error-prone replication and is reduced by stochastic and selective mechanisms that are incompletely understood. Defining how natural selection shapes RNA virus populations is critical because it can inform treatment paradigms and enhance control efforts. We allowed West Nile virus (WNV to replicate in wild-caught American crows, house sparrows and American robins to assess how natural selection shapes RNA virus populations in ecologically relevant hosts that differ in susceptibility to virus-induced mortality. After five sequential passages in each bird species, we examined the phenotype and population diversity of WNV through fitness competition assays and next generation sequencing. We demonstrate that fitness gains occur in a species-specific manner, with the greatest replicative fitness gains in robin-passaged WNV and the least in WNV passaged in crows. Sequencing data revealed that intrahost WNV populations were strongly influenced by purifying selection and the overall complexity of the viral populations was similar among passaged hosts. However, the selective pressures that control WNV populations seem to be bird species-dependent. Specifically, crow-passaged WNV populations contained the most unique mutations (~1.7× more than sparrows, ~3.4× more than robins and defective genomes (~1.4× greater than sparrows, ~2.7× greater than robins, but the lowest average mutation frequency (about equal to sparrows, ~2.6× lower than robins. Therefore, our data suggest that WNV replication in the most disease-susceptible bird species is positively associated with virus mutational tolerance, likely via complementation, and negatively associated with the strength of selection. These differences in genetic composition most likely have distinct phenotypic consequences for the virus populations. Taken together

  1. Genetic diversity and phylogenetic analysis of glycoprotein gp85 of avian leukosis virus subgroup J wild-bird isolates from Northeast China.

    Science.gov (United States)

    Jiang, Lili; Zeng, Xiangwei; Hua, Yuping; Gao, Qi; Fan, Zhaobin; Chai, Hongliang; Wang, Qi; Qi, Xiaole; Wang, Yongqiang; Gao, Honglei; Gao, Yulong; Wang, Xiaomei

    2014-07-01

    Avian leukosis virus subgroup J (ALV-J), first isolated in 1989, preferentially infects meat-type birds. Chinese layer flocks have experienced outbreaks of this virus since 2008. To analyze the status of ALV-J infection in wild birds in China, 585 wild birds collected from three provinces of Northeast China from 2010 to 2012 were tested, and six ALV-J strains were isolated for the first time. Furthermore, the gp85 genes of the six strains were amplified, cloned, and sequenced. The results indicated that two different ALV-J strains coexisted in Chinese wild birds from 2010 to 2012. These results not only expand the epidemiological data available for ALV-J and provide necessary information for the further understanding of the evolution of ALV-J, but they also highlight the potential role of wild-bird migration in the spread of ALV-J.

  2. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    Science.gov (United States)

    Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

    2015-01-01

    This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

  3. Internal quality evolution of a large test system – an industrial study

    Directory of Open Access Journals (Sweden)

    Kovács Attila

    2016-12-01

    Full Text Available This paper presents our empirical observations related to the evolution of a large automated test system. The system observed is used in the industry as a test tool for complex telecommunication systems, itself consisting of more than one million lines of source code. This study evaluates how different changes during the development have changed the number of observed Code Smells in the test system. We have monitored the development of the test scripts and measured the code quality characteristics over a five years period.

  4. Birds Generally Carry a Small Repertoire of Bitter Taste Receptor Genes.

    Science.gov (United States)

    Wang, Kai; Zhao, Huabin

    2015-09-04

    As they belong to the most species-rich class of tetrapod vertebrates, birds have long been believed to possess an inferior taste system. However, the bitter taste is fundamental in birds to recognize dietary toxins (which are typically bitter) in potential food sources. To characterize the evolution of avian bitter taste receptor genes (Tas2rs) and to test whether dietary toxins have shaped the repertoire size of avian Tas2rs, we examined 48 genomes representing all but 3 avian orders. The total number of Tas2r genes was found to range from 1 in the domestic pigeon to 12 in the bar-tailed trogon, with an average of 4, which suggested that a much smaller Tas2r gene repertoire exists in birds than in other vertebrates. Furthermore, we uncovered a positive correlation between the number of putatively functional Tas2rs and the abundance of potential toxins in avian diets. Because plant products contain more toxins than animal tissues and insects release poisonous defensive secretions, we hypothesized that herbivorous and insectivorous birds may demand more functional Tas2rs than carnivorous birds feeding on noninsect animals. Our analyses appear to support this hypothesis and highlight the critical role of taste perception in birds.

  5. Worldwide patterns of bird colouration on islands.

    Science.gov (United States)

    Doutrelant, Claire; Paquet, Matthieu; Renoult, Julien P; Grégoire, Arnaud; Crochet, Pierre-André; Covas, Rita

    2016-05-01

    Island environments share distinctive characteristics that offer unique opportunities to investigate parallel evolution. Previous research has produced evidence of an island syndrome for morphological traits, life-history strategies and ecological niches, but little is known about the response to insularity of other important traits such as animal signals. Here, we tested whether birds' plumage colouration is part of the island syndrome. We analysed with spectrophotometry the colouration of 116 species endemic to islands and their 116 closest mainland relatives. We found a pattern of reduced brightness and colour intensity for both sexes on islands. In addition, we found a decrease in the number of colour patches on islands that, in males, was associated with a decrease in the number of same-family sympatric species. These results demonstrate a worldwide pattern of parallel colour changes on islands and suggest that a relaxation of selection on species recognition may be one of the mechanisms involved.

  6. Carotenoids in bird testes: links to body carotenoid supplies, plumage coloration, body mass and testes mass in house finches (Carpodacus mexicanus).

    Science.gov (United States)

    Rowe, Melissah; Tourville, Elizabeth A; McGraw, Kevin J

    2012-01-01

    Carotenoid pigments can be allocated to different parts of the body to serve specific functions. In contrast to other body tissues, studies of carotenoid resources in the testes of animals are relatively scarce. We used high-performance liquid chromatography to determine the types and concentrations of carotenoids in the testes of house finches (Carpodacus mexicanus). Additionally, we examined the relationships between testes carotenoid concentrations and carotenoid pools in other body tissues, as well as body mass, testes mass and plumage coloration. We detected low concentrations of several carotenoids - lutein (the predominant carotenoid), zeaxanthin, anhydrolutein, β-cryptoxanthin, β-carotene and an unknown carotene - in the testes of wild house finches. We also found that testes lutein levels were significantly and positively associated with circulating lutein levels, while the concentration of zeaxanthin in testes was positively associated with zeaxanthin levels in liver, though in this instance the relationship was much weaker and only marginally significant. Furthermore, lutein levels in testes were significantly negatively associated with testes mass. Finally, plumage coloration was not associated with either the concentration of carotenoids in the testes or relative testes mass. These results suggest that testes carotenoids are reflective of the pool of circulating carotenoids in house finches, and that plumage coloration is unlikely to signal either the carotenoid content of testes tissue or a male's capacity for sperm production.

  7. From dinosaurs to modern bird diversity: extending the time scale of adaptive radiation.

    Science.gov (United States)

    Moen, Daniel; Morlon, Hélène

    2014-05-01

    What explains why some groups of organisms, like birds, are so species rich? And what explains their extraordinary ecological diversity, ranging from large, flightless birds to small migratory species that fly thousand of kilometers every year? These and similar questions have spurred great interest in adaptive radiation, the diversification of ecological traits in a rapidly speciating group of organisms. Although the initial formulation of modern concepts of adaptive radiation arose from consideration of the fossil record, rigorous attempts to identify adaptive radiation in the fossil record are still uncommon. Moreover, most studies of adaptive radiation concern groups that are less than 50 million years old. Thus, it is unclear how important adaptive radiation is over temporal scales that span much larger portions of the history of life. In this issue, Benson et al. test the idea of a "deep-time" adaptive radiation in dinosaurs, compiling and using one of the most comprehensive phylogenetic and body-size datasets for fossils. Using recent phylogenetic statistical methods, they find that in most clades of dinosaurs there is a strong signal of an "early burst" in body-size evolution, a predicted pattern of adaptive radiation in which rapid trait evolution happens early in a group's history and then slows down. They also find that body-size evolution did not slow down in the lineage leading to birds, hinting at why birds survived to the present day and diversified. This paper represents one of the most convincing attempts at understanding deep-time adaptive radiations.

  8. The evolution of pretransfusion testing: from agglutination to solid-phase red cell adherence tests.

    Science.gov (United States)

    Plapp, F V; Sinor, L T; Rachel, J M

    1989-01-01

    Hospital transfusion services and blood centers still use manual hemagglutination tests for most of their serological procedures. Automation of hemagglutination reactions has proven to be difficult, primarily because hemagglutination lacks an objective endpoint which can be easily interpreted by inexpensive instruments. Alternatively, solid-phase red cell adherence assays for ABO cell and serum grouping, Rh typing, red cell and platelet antibody screening, red cell and platelet crossmatching, IgA deficiency screening, hepatitis B surface antigen, and HIV antibody screening have been developed. The performance of these assays compares favorably with current hemagglutination and enzyme immunoassay methods. All of these tests share a common objective endpoint of adherence or nonadherence of indicator red cells. This uniformity allows easy interpretation of results visually, spectrophotometrically, or by image analysis. The latter technique has the potential to revolutionize the reading and interpretation of all agglutination tests. Solid-phase red cell adherence tests in microplates are ideal for batch processing large numbers of specimens. However, adherence tests are not restricted to this format. Therefore, blood grouping dipsticks have been produced, which permit testing of individual blood samples even outside of the laboratory.

  9. Female mating preferences and offspring survival: testing hypotheses on the genetic basis of mate choice in a wild lekking bird.

    Science.gov (United States)

    Sardell, Rebecca J; Kempenaers, Bart; Duval, Emily H

    2014-02-01

    Indirect benefits of mate choice result from increased offspring genetic quality and may be important drivers of female behaviour. 'Good-genes-for-viability' models predict that females prefer mates of high additive genetic value, such that offspring survival should correlate with male attractiveness. Mate choice may also vary with genetic diversity (e.g. heterozygosity) or compatibility (e.g. relatedness), where the female's genotype influences choice. The relative importance of these nonexclusive hypotheses remains unclear. Leks offer an excellent opportunity to test their predictions, because lekking males provide no material benefits and choice is relatively unconstrained by social limitations. Using 12 years of data on lekking lance-tailed manakins, Chiroxiphia lanceolata, we tested whether offspring survival correlated with patterns of mate choice. Offspring recruitment weakly increased with father attractiveness (measured as reproductive success, RS), suggesting attractive males provide, if anything, only minor benefits via offspring viability. Both male RS and offspring survival until fledging increased with male heterozygosity. However, despite parent-offspring correlation in heterozygosity, offspring survival was unrelated to its own or maternal heterozygosity or to parental relatedness, suggesting survival was not enhanced by heterozygosity per se. Instead, offspring survival benefits may reflect inheritance of specific alleles or nongenetic effects. Although inbreeding depression in male RS should select for inbreeding avoidance, mates were not less related than expected under random mating. Although mate heterozygosity and relatedness were correlated, selection on mate choice for heterozygosity appeared stronger than that for relatedness and may be the primary mechanism maintaining genetic variation in this system despite directional sexual selection.

  10. Test selection and optimization for PHM based on failure evolution mechanism model

    Institute of Scientific and Technical Information of China (English)

    Jing Qiu; Xiaodong Tan; Guanjun Liu; Kehong LÜ

    2013-01-01

    The test selection and optimization (TSO) can improve the abilities of fault diagnosis, prognosis and health-state evalua-tion for prognostics and health management (PHM) systems. Tra-ditional y, TSO mainly focuses on fault detection and isolation, but they cannot provide an effective guide for the design for testa-bility (DFT) to improve the PHM performance level. To solve the problem, a model of TSO for PHM systems is proposed. Firstly, through integrating the characteristics of fault severity and propa-gation time, and analyzing the test timing and sensitivity, a testabi-lity model based on failure evolution mechanism model (FEMM) for PHM systems is built up. This model describes the fault evolution-test dependency using the fault-symptom parameter matrix and symptom parameter-test matrix. Secondly, a novel method of in-herent testability analysis for PHM systems is developed based on the above information. Having completed the analysis, a TSO model, whose objective is to maximize fault trackability and mini-mize the test cost, is proposed through inherent testability analysis results, and an adaptive simulated annealing genetic algorithm (ASAGA) is introduced to solve the TSO problem. Final y, a case of a centrifugal pump system is used to verify the feasibility and effectiveness of the proposed models and methods. The results show that the proposed technology is important for PHM systems to select and optimize the test set in order to improve their perfor-mance level.

  11. Could strange stars be in the color-flavor-locked phase: Tested by their thermal evolutions

    Science.gov (United States)

    Cheng, Quan; Yu, Yun-Wei; Zheng, Xiao-Ping

    2013-03-01

    The thermal evolution of strange stars in both normal and color-flavor-locked (CFL) phases are investigated together with the evolutions of the stellar rotation and the r-mode instability. The heating effects due to the deconfinement transition of the stellar crust and the dissipation of the r-modes are considered. As a result, the cooling of the stars in the normal phase is found to be not very different from the standard one. In contrast, for the stars in the CFL phase, a big bump during the first hundred years and a steep decay (˜7% in ten years) at the ages of ˜104-6yrs are predicted in their thermal evolution curves. These unique features provide an effective observational test for determining whether or not the CFL phase is reached in strange stars. This thermal test method is independent of and complementary to the rotational test method, which is a direct consequence of the r-mode instability [see J. Madsen, Phys. Rev. Lett. 85, 10 (2000)].

  12. Could strange stars be in the color-flavor-locked phase: Tested by their thermal evolutions

    CERN Document Server

    Cheng, Quan; Zheng, Xiao-Ping; 10.1103/PhysRevD.87.063009

    2013-01-01

    The thermal evolution of strange stars in both normal and color-flavor-locked (CFL) phases are investigated together with the evolutions of the stellar rotation and the r-mode instability. The heating effects due to the deconfinement transition of the stellar crust and the dissipation of the r-modes are considered. As a result, the cooling of the stars in the normal phase is found to be not very different from the standard one. In contrast, for the stars in the CFL phase, a big bump during the first hundred years and a steep decay ($\\sim$7% in ten years) at the ages of $\\sim10^{4-6}$ yrs are predicted in their thermal evolution curves. These unique features provide an effective observational test for determining whether or not the CFL phase is reached in strange stars. This thermal test method is independent of and complementary to the rotational test method, which is a direct consequence of the r-mode instability.

  13. Bird Avoidance Model

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an unpublished report on the bird avoidance model to predict bird strike hazards with low flying aircraft. Included is peak periods for different species of...

  14. Avian Influenza in Birds

    Science.gov (United States)

    ... this? Submit Button Past Newsletters Avian Influenza in Birds Language: English Español Recommend on Facebook Tweet ... illness. Top of Page Avian Influenza in Wild Birds Avian influenza A viruses have been isolated from ...

  15. Birds Kept as Pets

    Science.gov (United States)

    ... Patients Infants and Young Children Publications & Materials Announcements Birds Kept as Pets Recommend on Facebook Tweet Share ... your hands whenever you play or work with birds Person washing their hands with soap and water. ...

  16. BIRD FLU (AVIAN INFLUENZA

    Directory of Open Access Journals (Sweden)

    Ali ACAR

    2005-12-01

    Full Text Available Avian influenza (bird flu is a contagious disease of animals caused by influenza A viruses. These flu viruses occur naturally among birds. Actually, humans are not infected by bird flu viruses.. However, during an outbreak of bird flu among poultry, there is a possible risk to people who have contact infect birds or surface that have been contaminated with excreations from infected birds. Symptoms of bird flu in humans have ranged from typical flu-like symptoms to eye infections, pneumonia, severe respiratory diseases and other severe and life-threatening complications. In such situation, people should avoid contact with infected birds or contaminated surface, and should be careful when handling and cooking poultry. [TAF Prev Med Bull 2005; 4(6.000: 345-353

  17. Genome evolution in Reptilia: in silico chicken mapping of 12,000 BAC-end sequences from two reptiles and a basal bird

    Directory of Open Access Journals (Sweden)

    Edwards Scott V

    2009-07-01

    Full Text Available Abstract Background With the publication of the draft chicken genome and the recent production of several BAC clone libraries from non-avian reptiles and birds, it is now possible to undertake more detailed comparative genomic studies in Reptilia. Of interest in particular are the genomic events that transformed the large, repeat-rich genomes of mammals and non-avian reptiles into the minimalist chicken genome. We have used paired BAC end sequences (BESs from the American alligator (Alligator mississippiensis, painted turtle (Chrysemys picta and emu (Dromaius novaehollandiae to investigate patterns of sequence divergence, gene and retroelement content, and microsynteny between these species and chicken. Results From a total of 11,967 curated BESs, we successfully mapped 725, 773 and 2597 sequences in alligator, turtle, and emu, respectively, to sites in the draft chicken genome using a stringent BLAST protocol. Most commonly, sequences mapped to a single site in the chicken genome. Of 1675, 1828 and 2936 paired BESs obtained for alligator, turtle, and emu, respectively, a total of 34 (alligator, 2%, 24 (turtle, 1.3% and 479 (emu, 16.3% pairs were found to map with high confidence and in the correct orientation and with BAC-sized intermarker distances to single chicken chromosomes, including 25 such paired hits in emu mapping to the chicken Z chromosome. By determining the insert sizes of a subset of BAC clones from these three species, we also found a significant correlation between the intermarker distance in alligator and turtle and in chicken, with slopes as expected on the basis of the ratio of the genome sizes. Conclusion Our results suggest that a large number of small-scale chromosomal rearrangements and deletions in the lineage leading to chicken have drastically reduced the number of detected syntenies observed between the chicken and alligator, turtle, and emu genomes and imply that small deletions occurring widely throughout the

  18. Modeling Extinction Risk of Endemic Birds of Mainland China

    Directory of Open Access Journals (Sweden)

    Youhua Chen

    2013-01-01

    Full Text Available The extinction risk of endemic birds of mainland China was modeled over evolutionary time. Results showed that extinction risk of endemic birds in mainland China always tended to be similar within subclades over the evolutionary time of species divergence, and the overall evolution of extinction risk of species presented a conservatism pattern, as evidenced by the disparity-through-time plot. A constant-rate evolutionary model was the best one to quantify the evolution of extinction risk of endemic birds of mainland China. Thus, there was no rate shifting pattern for the evolution of extinction risk of Chinese endemic birds over time. In a summary, extinction risk of endemic birds of mainland China is systematically quantified under the evolutionary framework in the present work.

  19. Audubon Bird Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    Included are a student reader, "The Story of Birds," a leaders' guide, a large colored Audubon bird chart, and a separate guide for the chart. The student reader is divided into eleven sections which relate to the various physical and behavioral features of birds such as feathers, feeding habits as related to the shape of bills and feet, nests,…

  20. A Clever Bird

    Institute of Scientific and Technical Information of China (English)

    张仰清

    2000-01-01

    A man in Australia had a wonderful bird. There was no other bird like it . It was very,very clever. The bird could say any word --except one. It could not say the name of the town where it was born. The name of that town was Catano.

  1. Are morphometrics sufficient for estimating age of pre-fledging birds in the field? A test using common terns (Sterna hirundo.

    Directory of Open Access Journals (Sweden)

    Christy N Wails

    Full Text Available Age is a key component of fitness, affecting survival and reproductive capacities. Where it is not possible to study known individuals from birth, morphometrics (predominantly patterns of plumage development for birds are most often used to estimate age. Although criteria for age estimations exist for many species, the degree to which these criteria improve the precision of estimates remains to be tested, restricting their widespread acceptance. We develop a photographic tool for estimating ages of Common Tern (Sterna hirundo chicks and test it using 100 human observers of varying prior experience across four breeding colonies (three North American sites and one European site and under controlled laboratory conditions. We followed the design approach of other morphometric tools, expanding it to create a user-friendly guide (divided into six age groupings. The majority (86% of observers improved in chick-aging accuracy when using the tool by an average of 20.1% (±1.4 SE and correctly estimated 60.3% (±1.4 of chick ages. This was similar to the intrinsic aging ability of our best field observer (63.3%. Observers with limited experience showed the greatest increases in chick-aging accuracy over experienced observers who likely had established a method for estimating chick ages prior to using the tool. Even the best observers only correctly estimated ages of chicks 62.9% (±2.8 of the time in the field and 84.0% (±2.9 of the time in the lab when using the tool and typically underestimated ages. This indicates that developmental variation between individual chicks can prevent completely reliable age estimates and corroborates the few existing data that suggest that morphometric criteria fail to achieve robust levels of accuracy and may introduce error into studies that rely on them. We conclude that novel approaches for estimating age, not only morphometric criteria, must be pursued.

  2. 鸟类迁徙:在全球变暖趋势下的演化、调控与发展(英文)%BIRD MIGRATION: THE PRESENT VIEW OF EVOLUTION, CONTROL, AND FURTHER DEVELOPMENT AS GLOBAL WARMING PROGRESSES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    migration period, (ii) the amount of migratory activity, a genetically prescribed parameter that determines the distance over which the bird flies, (iii) the migration directions and (iv) physiological parameters, in particular fat deposition during the migratory period, but also those determining which individuals will migrate and which will not in forms that are obligatorily partial migrants. A two-way selection experiment has shown that within only a few generations partial migrants can be converted by selection into pure migrants or nonmigrants. Selection for a new migration direction, leading to new winter quarters, can occur equally rapidly in free-living birds. At least in the species most closely studied so far (the blackcap, Sylvia atricapilla), the attributes "migrant" or "nonmigrant" are inherited in conjunction with the characteristic amount of migratory activity (as a time program), and the former are evidently controlled by a threshold mechanism. A new bird-migration theory postulates that even in forms that at present are exclusively migratory, selection for lower levels of migratory activity can cause a threshold to be crossed, below which nonmigrants appear. Accordingly, conversion of a population from migratory to nonmigratory can occur by selection with a transition through partial migration. This intermediate stage is prevalent among the recent bird species; it appeared early in the evolution of organisms and in the case of birds was probably acquired from ancestral, pre-avian forms. Model calculations indicate that with strictly directed selection, migratory birds can be converted to sedentary in about 40 years and conversely. This explains the changes in migratory behaviour currently observable in so many bird species in the course of global warming; in particular, migratoriness is decreasing in various respects at higher latitudes. The new theory also enables us to predict the ways in which avifaunas are likely to be restructured if warming continues

  3. Archaeopteryx: Dinosaur or Bird?

    Institute of Scientific and Technical Information of China (English)

    SONG Jianlan

    2011-01-01

    @@ An Archaeopteryx-like theropod dinosaur newly found from western Liaoning Province in northeastern China would make an unusual, if not unwelcome, gift for the 150th birthday of Archaeopteryx, the oldest bird as long-believed by paleontologists: Named as Xiaotingia zhengiis, the new species carries some critical traits suggesting that Archaeopteryx might have actually been a dinosaur.Naturally this breaking news stirred intense controversies.Was "The Oldest Bird" a bird? If not, what makes a bird? With these questions in mind, the author joined an exploration in search of "the real first bird" along with the paleontologists at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) under CAS.

  4. Teste do efeito de borda na predação de ninhos naturais e artificiais no Cerrado A test of the edge effect on predation of natural and artificial bird nests in the Cerrado

    Directory of Open Access Journals (Sweden)

    Letice C. França

    2009-06-01

    Full Text Available The Cerrado is still one of the most important ecosystems in Brazil, even though more than 50% of its area has been altered or converted to pastureland and plantations. Despite its intense degradation, few ecological processes that might affect its biodiversity have been evaluated. The goal of this study was to test the edge effect on the predation rates at natural and artificial nests, at the Ecological Station of Águas Emendadas, Federal District, Brazil. Natural nests were found and monitored every three to four days from September to December of 2004 in the interior and at the edge of the reserve. Artificial nests were placed at four distances from the edge (0, 500, 1000 and 2000 m in three spatial replicates in September and again in December of 2004. Each nest received one Japanese Quail and one plasticine egg and was monitored every five days, for 15 days. There was no difference between the rates of predation either in the natural nests or in the artificial nests between treatments. For one bird species, Elaenia chiriquensis (Lawrence, 1865, Tyrannidae, daily survival rates in the incubation and in the hatchling period had opposite values between the edge and the interior. Marks on plasticine eggs suggest that birds are the main predators. Estimates of the abundance of two potential nest predators, Cyanocorax cristatellus (Temminck, 1823, Corvidae and Canis familiaris (Linnaeus, 1758, Canidae, revealed no relationship with distance to the edge, nor with predation rates. Brood parasitism of natural nests was similar between the interior (0% and the edge (3.8% of the nests. The results described here do not support the edge effect hypothesis for nest predation rates on either natural or artificial nests, nor for brood parasitism rates.

  5. American Samoa ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabirds, wading birds, shorebirds, waterfowl, and gulls and terns in American Samoa. Vector polygons...

  6. Exotic birds increase generalization and compensate for native bird decline in plant-frugivore assemblages.

    Science.gov (United States)

    García, Daniel; Martínez, Daniel; Stouffer, Daniel B; Tylianakis, Jason M

    2014-11-01

    Exotic species are thought to alter the structure of natural communities and disrupt ecosystem functioning through invasion. Nevertheless, exotic species may also provide ecological insurance when they contribute to maintain ecosystem functions after the decline of native species following anthropogenic disturbance. Here, this hypothesis is tested with the assemblage of frugivorous birds and fleshy-fruited plants of New Zealand, which has suffered strong historical declines in native birds while simultaneously gaining new frugivores introduced by European settlers. We studied the plant-frugivore assemblage from measures of fruit and bird abundances and fruit consumption in nine forest patches, and tested how this changed across a gradient of relative abundance of exotic birds. We then examined how each bird species' role in the assemblage (the proportion of fruits and the number of plant species consumed) varied with their relative abundance, body size and native/exotic status. The more abundant and, to a lesser extent, larger birds species consumed a higher proportion of fruits from more plant species. Exotic birds consumed fruits less selectively and more proportionate to the local availability than did native species. Interaction networks in which exotic birds had a stronger role as frugivores had higher generalization, higher nestedness and higher redundancy of plants. Exotic birds maintained frugivory when native birds became rarer, and diversified the local spectrum of frugivores for co-occurring native plants. These effects seemed related to the fact that species abundances, rather than trait-matching constraints, ultimately determined the patterns of interactions between birds and plants. By altering the structure of plant-frugivore assemblages, exotic birds likely enhance the stability of the community-wide seed dispersal in the face of continued anthropogenic impact.

  7. Microstructure evolution during cyclic tests on EUROFER 97 at room temperature. TEM observation and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Giordana, M.F., E-mail: giordana@ifir-conicet.gov.ar [Instituto de Fisica Rosario, CONICET-UNR, Bv. 27 de Febrero 210 Bis, 2000 Rosario (Argentina); Giroux, P.-F. [Commissariat a l' Energie Atomique, DEN/DANS/DMN/SRMA, 91191 Gif-sur-Yvette Cedex (France); Alvarez-Armas, I. [Instituto de Fisica Rosario, CONICET-UNR, Bv. 27 de Febrero 210 Bis, 2000 Rosario (Argentina); Sauzay, M. [Commissariat a l' Energie Atomique, DEN/DANS/DMN/SRMA, 91191 Gif-sur-Yvette Cedex (France); Armas, A. [Instituto de Fisica Rosario, CONICET-UNR, Bv. 27 de Febrero 210 Bis, 2000 Rosario (Argentina); Kruml, T. [CEITEC IPM, Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, Brno, 616 62 (Czech Republic)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer Low cycle fatigue test are carried out on EUROFER 97 at room temperature. Black-Right-Pointing-Pointer EUROFER 97 shows a pronounced cyclic softening accompanied by microstructural changes. Black-Right-Pointing-Pointer Cycling induces a decrement in dislocation density and subgrain growth. Black-Right-Pointing-Pointer A simple mean-field model based on crystalline plasticity is proposed. Black-Right-Pointing-Pointer The mean subgrain size evolution is predicted by modelling. - Abstract: The 9% Cr quenched and tempered reduced-activation ferritic/martensitic steel EUROFER 97 is one of the candidates for structural components of fusion reactors. Isothermal, plastic strain-controlled, low-cycle fatigue tests are performed. Tested at room temperature, this steel suffers a cyclic softening effect linked to microstructural changes observed by transmission electron microscopy, such as the decrease of dislocation density inside subgrains or the growth of subgrain size. From the assumed mechanisms of softening a simple mean-field model based on crystalline plasticity is proposed to predict these microstructure evolutions during cycling and monotonic deformation.

  8. Microstructural evolution in the HAZ of Inconel 718 and correlation with the hot ductility test

    Science.gov (United States)

    Thompson, R. G.; Genculu, S.

    1983-01-01

    The nickel-base alloy 718 was evaluated to study the role of preweld heat treatment in reducing or eliminating heat-affected zone hot cracking. Three heat treatments were studied using the Gleeble hot ductility test. A modified hot ductility test was also used to follow the evolution of microstructure during simulated welding thermal cycles. The microstructural evolution was correlated with the hot ductility data in order to evaluate the mechanism of hot cracking in alloy 718. The correlation of hot ductility with microstructure showed that recrystallization, grain growth, and dissolution of precipitates did not in themselves cause any loss of ductility during cooling. Ductility loss during cooling was not initiated until the constitutional liquation of NbC particles was observed in the microstructure. Laves-type phases were found precipitated in the solidified grain boundaries but were not found to correlate with any ductility loss parameter. Mechanisms are reviewed which help to explain how heat treatment controls the hot crack susceptibility of alloy 718 as measured in the hot ductility test.

  9. NGC 1866: A Critical test of Stellar Evolution for Intermediate Mass Stars

    Science.gov (United States)

    Walker, Alistair

    1999-07-01

    We propose to obtain V {F555W} and I {F814W} images centered on the LMC cluster NGC 1866, with a range of exposure times such that we can measure all cluster stars from the brightest at V 15 down to V 25. NGC 1866 has age 100 Myr and is so populous that the evolving stars, with M 5 M_sun, are caught even in short phases of evolution. As such, it provides a critical test of stellar evolution theory applicable to these intermediate mass stars. We will prepare a color- magnitude diagram that will, for the first time, include all the luminous evolved stars. This is impossible to achieve from ground-based observations due to crowding. We will also measure a luminosity function for the unevolved main sequence to M 0.5 M_sun which allows both determination of the IMF for cluster stars with masses in the range 0.5 - 5 M_sun and an investigation of the cluster dynamical evolution by study of the spatial mass distribution. The deep and accurate MS photometry will also permit precise fitting of a fiducial ZAMS, and hence derivation of a distance relative to the Hyades, the basis of the ZAMS calibration. Since NGC 1866 contains at least 23 Cepheid variables, we will thus calibrate the Period-Luminosity relation zeropoint, and determine the distance to the LMC relative to the very accurate Hipparcos parallax distance to the Hyades with a minimum of steps and assumptions.

  10. Evolution of viviparity: a phylogenetic test of the cold-climate hypothesis in phrynosomatid lizards.

    Science.gov (United States)

    Lambert, Shea M; Wiens, John J

    2013-09-01

    The evolution of viviparity is a key life-history transition in vertebrates, but the selective forces favoring its evolution are not fully understood. With >100 origins of viviparity, squamate reptiles (lizards and snakes) are ideal for addressing this issue. Some evidence from field and laboratory studies supports the "cold-climate" hypothesis, wherein viviparity provides an advantage in cold environments by allowing mothers to maintain higher temperatures for developing embryos. Surprisingly, the cold-climate hypothesis has not been tested using both climatic data and phylogenetic comparative methods. Here, we investigate the evolution of viviparity in the lizard family Phrynosomatidae using GIS-based environmental data, an extensive phylogeny (117 species), and recently developed comparative methods. We find significant relationships between viviparity and lower temperatures during the warmest (egg-laying) season, strongly supporting the cold-climate hypothesis. Remarkably, we also find that viviparity tends to evolve more frequently at tropical latitudes, despite its association with cooler climates. Our results help explain this and two related patterns that seemingly contradict the cold-climate hypothesis: the presence of viviparous species restricted to low-elevation tropical regions and the paucity of viviparous species at high latitudes. Finally, we examine whether viviparous taxa may be at higher risk of extinction from anthropogenic climate change.

  11. A Classroom Exercise for Testing Urban Myth: Does Wedding Rice Cause Birds to Explode or Were Ann Landers, Martha Stewart & Bart Simpson Wrong?

    Science.gov (United States)

    Krupa, James J.

    2005-01-01

    In this article, the author first provides the history of the wedding rice myth. He then details an interactive class activity that involved students in his large, non-majors biology classes. These students developed a series of experiments that scientifically determined if rice could be harmful to birds. Finally, he provides suggestions on how…

  12. Experimental test of postfire management in pine forests: impact of salvage logging versus partial cutting and nonintervention on bird-species assemblages.

    Science.gov (United States)

    Castro, Jorge; Moreno-Rueda, Gregorio; Hódar, José A

    2010-06-01

    There is an intense debate about the effects of postfire salvage logging versus nonintervention policies on regeneration of forest communities, but scant information from experimental studies is available. We manipulated a burned forest area on a Mediterranean mountain to experimentally analyze the effect of salvage logging on bird-species abundance, diversity, and assemblage composition. We used a randomized block design with three plots of approximately 25 ha each, established along an elevational gradient in a recently burned area in Sierra Nevada Natural and National Park (southeastern Spain). Three replicates of three treatments differing in postfire burned wood management were established per plot: salvage logging, nonintervention, and an intermediate degree of intervention (felling and lopping most of the trees but leaving all the biomass). Starting 1 year after the fire, we used point sampling to monitor bird abundance in each treatment for 2 consecutive years during the breeding and winter seasons (720 censuses total). Postfire burned-wood management altered species assemblages. Salvage logged areas had species typical of open- and early-successional habitats. Bird species that inhabit forests were still present in the unsalvaged treatments even though trees were burned, but were almost absent in salvage-logged areas. Indeed, the main dispersers of mid- and late-successional shrubs and trees, such as thrushes (Turdus spp.) and the European Jay (Garrulus glandarius) were almost restricted to unsalvaged treatments. Salvage logging might thus hamper the natural regeneration of the forest through its impact on assemblages of bird species. Moreover, salvage logging reduced species abundance by 50% and richness by 40%, approximately. The highest diversity at the landscape level (gamma diversity) resulted from a combination of all treatments. Salvage logging may be positive for bird conservation if combined in a mosaic with other, less-aggressive postfire

  13. A quantitative test of Hamilton's rule for the evolution of altruism.

    Directory of Open Access Journals (Sweden)

    Markus Waibel

    2011-05-01

    Full Text Available The evolution of altruism is a fundamental and enduring puzzle in biology. In a seminal paper Hamilton showed that altruism can be selected for when rb - c > 0, where c is the fitness cost to the altruist, b is the fitness benefit to the beneficiary, and r is their genetic relatedness. While many studies have provided qualitative support for Hamilton's rule, quantitative tests have not yet been possible due to the difficulty of quantifying the costs and benefits of helping acts. Here we use a simulated system of foraging robots to experimentally manipulate the costs and benefits of helping and determine the conditions under which altruism evolves. By conducting experimental evolution over hundreds of generations of selection in populations with different c/b ratios, we show that Hamilton's rule always accurately predicts the minimum relatedness necessary for altruism to evolve. This high accuracy is remarkable given the presence of pleiotropic and epistatic effects as well as mutations with strong effects on behavior and fitness (effects not directly taken into account in Hamilton's original 1964 rule. In addition to providing the first quantitative test of Hamilton's rule in a system with a complex mapping between genotype and phenotype, these experiments demonstrate the wide applicability of kin selection theory.

  14. Dosage compensation in birds

    OpenAIRE

    McQueen, H A; McBride, D; Miele, G; Bird, A.P.; Clinton, M

    2001-01-01

    The Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess "dosage compensation" systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mamma...

  15. Tropical birds have a slow pace of life

    OpenAIRE

    Wiersma, Popko; Muñoz-Garcia, Agustí; Walker, Amy; Williams, Joseph B.

    2007-01-01

    Tropical birds are relatively long-lived and produce few offspring, which develop slowly and mature relatively late in life, the slow end of the life-history axis, whereas temperate birds lie at the opposite end of this continuum. We tested the hypothesis that tropical birds have evolved a reduced basal metabolic rate (BMR). We measured BMR of 69 species of tropical birds, the largest data set amassed on metabolic rates of tropical birds, and compared these measurements with 59 estimates of B...

  16. Coastal Resources Atlas: Long Island: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  17. Cross-species transmission and emergence of novel viruses from birds.

    Science.gov (United States)

    Chan, Jasper Fuk-Woo; To, Kelvin Kai-Wang; Chen, Honglin; Yuen, Kwok-Yung

    2015-02-01

    Birds, the only living member of the Dinosauria clade, are flying warm-blooded vertebrates displaying high species biodiversity, roosting and migratory behavior, and a unique adaptive immune system. Birds provide the natural reservoir for numerous viral species and therefore gene source for evolution, emergence and dissemination of novel viruses. The intrusions of human into natural habitats of wild birds, the domestication of wild birds as pets or racing birds, and the increasing poultry consumption by human have facilitated avian viruses to cross species barriers to cause zoonosis. Recently, a novel adenovirus was exclusively found in birds causing an outbreak of Chlamydophila psittaci infection among birds and humans. Instead of being the primary cause of an outbreak by jumping directly from bird to human, a novel avian virus can be an augmenter of another zoonotic agent causing the outbreak. A comprehensive avian virome will improve our understanding of birds' evolutionary dynamics.

  18. Insights into the evolution of mammalian telomerase: Platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes

    Directory of Open Access Journals (Sweden)

    Hrdličková Radmila

    2012-06-01

    Full Text Available Abstract Background The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT ortholog, and provide a comparison with genes of other vertebrates. Results The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. Conclusions OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes.

  19. Mesozoic birds of China-a synoptic review

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhonghe; ZHANG Fucheng

    2007-01-01

    A synoptic review of the discoveries and studies of Chinese Mesozoic birds is provided in this paper.40Ar/39Ar dating of several bird-bearing deposits in the Jehol Group has established a geochronological framework for the study of the early avian radiation.Chinese Mesozoic birds had lasted for at least 11 Ma during about 131 Ma and 120 Ma (Barremian to Aptian)of the middle and late Early Cretaceous,respectively.In order to further evaluate the change of the avian diversity in the Jehol Biota,six new orders and families are erected based on known genera and species,which brings the total number of orders of Chinese Mesozoic birds to 15 and highlights a remarkable radiation ever since the first appearante of birds in the Late Jurassic.Chinese Early Cretaceous birds had experienced a significant differentiation in morphology,flight,diet and habitat.Further examination of the foot of Jeholornis suggests this bird might not have possessed a fully reversed hallux.However,the attachment of metatarsal Ⅰ to the medial side of metatarsal Ⅱ does not preclude trunk climbing,a pre-adaptation for well developed perching life of early birds.Arboreality had proved to be a key adaptation in the origin and early evolution of bird flight,and the adaptation to lakeshore environment had played an equally important role in the origin of omithurine birds and their near-modern flight skill.Many Chinese Early Cretaceous birds had preserved the direct evidence of their diet,showing that the most primitive birds were probably mainly insectivorous and that specialized herbivorous or carnivorous (e.g.,piscivorous)dietary adaptation had appeared only in later advanced forms.The only known Early Cretaceous bird embryo fossil has shown that precocial birds had occurred prior to altricial birds in avian history,and the size of the embryo and other analysis indicate it probably had a short incubation period.Leg feathers probably have a wide range of distribution in early birds

  20. Genetics of colouration in birds.

    Science.gov (United States)

    Roulin, Alexandre; Ducrest, Anne-Lyse

    2013-01-01

    Establishing the links between phenotype and genotype is of great importance for resolving key questions about the evolution, maintenance and adaptive function of phenotypic variation. Bird colouration is one of the most studied systems to investigate the role of natural and sexual selection in the evolution of phenotypic diversity. Given the recent advances in molecular tools that allow discovering genetic polymorphisms and measuring gene and protein expression levels, it is timely to review the literature on the genetics of bird colouration. The present study shows that melanin-based colour phenotypes are often associated with mutations at melanogenic genes. Differences in melanin-based colouration are caused by switches of eumelanin to pheomelanin production or by changes in feather keratin structure, melanoblast migration and differentiation, as well as melanosome structure. Similar associations with other types of colourations are difficult to establish, because our knowledge about the molecular genetics of carotenoid-based and structural colouration is quasi inexistent. This discrepancy stems from the fact that only melanin-based colouration shows pronounced heritability estimates, i.e. the resemblance between related individuals is usually mainly explained by genetic factors. In contrast, the expression of carotenoid-based colouration is phenotypically plastic with a high sensitivity to variation in environmental conditions. It therefore appears that melanin-based colour traits are prime systems to understand the genetic basis of phenotypic variation. In this context, birds have a great potential to bring us to new frontiers where many exciting discoveries will be made on the genetics of phenotypic traits, such as colouration. In this context, a major goal of our review is to suggest a number of exciting future avenues.

  1. What Is Bird Flu?

    Institute of Scientific and Technical Information of China (English)

    邢连香

    2004-01-01

    What is bird flu? It's a form of influenza believed to strike all birds. Though poultry (家禽)are believed to be especially prone to (倾向于)humans, no human-to-human transmission(传播) has been reported.

  2. Nanoscale magnetoreceptors in birds

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2012-01-01

    The Earth's magnetic field provides an important source of directional information for many living organisms, especially birds, but the sensory receptor responsible for magnetic field detection still has to be identified. Recently, magnetic iron oxide particles were detected in dendritic endings...... field, by a bird....

  3. HST images of FeLoBAL quasars: Testing quasar-galaxy evolution models

    Science.gov (United States)

    Herbst, Hanna; Hamann, Fred; Villforth, Carolin; Caselli, Paola; Koekemoer, Anton M.; Veilleux, Sylvain

    2016-01-01

    We present preliminary results from an HST imaging study of FeLoBAL quasars, which have extremely low-ionization Broad Absorption Line (BAL) outflows and might be a young quasar population based on their red colors, large far-IR luminosities (suggesting high star formation rates), and powerful outflows. Some models of quasar - host galaxy evolution propose a triggering event, such as a merger, to fuel both a burst of star formation and the quasar/AGN activity. These models suggest young quasars are initially obscured inside the dusty starburst until a "blowout" phase, driven by the starburst or quasar outflows like FeLoBALs, ends the star formation and reveals the visibly luminous quasar. Despite the popularity of this evolution scheme, there is little observational evidence to support the role of mergers in triggering AGN or the youth of dust-reddened quasars (such as FeLoBALs) compared to normal blue quasars.Our Cycle 22 HST program is designed to test the youth of FeLoBAL quasars and the connection of FeLoBALs to mergers. We obtain WFC3/IR F160W images of 10 FeLoBAL quasars at redshift z~0.9 (covering ~8500A in the quasar rest frame). We will compare the host galaxy morphologies and merger signatures of FeLoBALs with normal blue quasars (which are older according to the evolution model) and non-AGN galaxies matched in redshift and stellar mass. If FeLoBAL quasars are indeed in a young evolutionary state, close in time to the initial merging event, they should have stronger merger features compared to blue quasars and non-AGN galaxies. Preliminary results suggest that this is not the case - FeLoBAL quasars appear to reside in faint, compact hosts with weak or absent merger signatures. We discuss the implications of these results for galaxy evolution models and other studies of dust-reddened quasar populations.

  4. Birds as biodiversity surrogates

    DEFF Research Database (Denmark)

    Larsen, Frank Wugt; Bladt, Jesper Stentoft; Balmford, Andrew

    2012-01-01

    1. Most biodiversity is still unknown, and therefore, priority areas for conservation typically are identified based on the presence of surrogates, or indicator groups. Birds are commonly used as surrogates of biodiversity owing to the wide availability of relevant data and their broad popular...... appeal. However, some studies have found birds to perform relatively poorly as indicators. We therefore ask how the effectiveness of this approach can be improved by supplementing data on birds with information on other taxa. 2. Here, we explore two strategies using (i) species data for other taxa...... areas identified on the basis of birds alone performed well in representing overall species diversity where birds were relatively speciose compared to the other taxa in the data sets. Adding species data for one taxon increased surrogate effectiveness better than adding genus- and family-level data...

  5. Anatomy of a Bird

    Science.gov (United States)

    2007-12-01

    further surprises. The 'head' and major parts of the 'Bird' are moving apart at more than 400 km/s (1.4 million km/h!). Observing such high velocities is very rare in merging galaxies. Also, the 'head' appears to be the major source of infrared luminosity in the system, though it is the smallest of the three galaxies. "It seems that NACO has caught the action right at the time of the first high-speed fly-by of the 'head' galaxy through the system consisting of the other two galaxies," says Seppo Mattila, member of the discovery team. "These two galaxies must have met earlier, probably a couple of hundred million years ago." The 'head' is forming stars violently, at a rate of nearly 200 solar masses per year, while the other two galaxies appear to be at a more quiescent epoch of their interaction-induced star formation history. The 'Bird' belongs to the prestigious family of luminous infrared galaxies, with an infrared luminosity nearly one thousand billion times that of the Sun. This family of galaxies has long been thought to signpost important events in galaxy evolution, such as mergers of galaxies, which in turn trigger bursts of star formation, and may eventually lead to the formation of a single elliptical galaxy. The findings presented here are reported in a paper to appear in a future issue of the journal Monthly Notices of the Royal Astronomical Society ("Adaptive optics imaging and optical spectroscopy of a multiple merger in a luminous infrared galaxy", by P. Väisänen" et al.). Note [1]: The team is composed of P. Väisänen, A. Kniazev, D. A. H. Buckley, L. Crause, Y. Hashimoto, N. Loaring, E. Romero-Colmenero, and M. Still (SAAO, South Africa), S. Mattila (Tuorla Observatory, Finland), A. Adamo and G. Östlin (Stockholm University, Sweden), A. Efstathiou (Cyprus College, Nicosia, Cyprus), D. Farrah (Cornell University, USA), P. H. Johansson (Universitäts-Sternwarte München, Germany), E. B. Burgh and K. Nordsieck (University of Wisconsin, USA), P. Lira

  6. Fracturing tests on reservoir rocks: Analysis of AE events and radial strain evolution

    CERN Document Server

    Pradhan, S; Fjær, E; Stenebråten, J; Lund, H K; Sønstebø, E F; Roy, S

    2015-01-01

    Fracturing in reservoir rocks is an important issue for the petroleum industry - as productivity can be enhanced by a controlled fracturing operation. Fracturing also has a big impact on CO2 storage, geothermal installation and gas production at and from the reservoir rocks. Therefore, understanding the fracturing behavior of different types of reservoir rocks is a basic need for planning field operations towards these activities. In our study, the fracturing of rock sample is monitored by Acoustic Emission (AE) and post-experiment Computer Tomography (CT) scans. The fracturing experiments have been performed on hollow cylinder cores of different rocks - sandstones and chalks. Our analysis show that the amplitudes and energies of acoustic events clearly indicate initiation and propagation of the main fractures. The amplitudes of AE events follow an exponential distribution while the energies follow a power law distribution. Time-evolution of the radial strain measured in the fracturing-test will later be comp...

  7. 14 CFR 35.36 - Bird impact.

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or analysis based on tests or experience on similar designs, that the propeller can withstand the impact of...

  8. Immunogenic proteins specific to different bird species in bird fancier's lung.

    Science.gov (United States)

    Rouzet, Adeline; Reboux, Gabriel; Rognon, Bénédicte; Barrera, Coralie; De Vuyst, Paul; Dalphin, Jean-Charles; Millon, Laurence; Roussel, Sandrine

    2014-01-01

    Bird fancier's lung (BFL) is a disease produced by exposure to avian proteins present in droppings, blooms, and serum of a variety of birds. Although serological test results are currently used to confirm clinical diagnosis of the disease, bird species specificity is poorly understood. This study aimed to contribute to a better understanding of the specificity of immunogenic proteins revealed from the droppings of three bird species. Sera from four patients with BFL and two controls without exposure were analyzed by Western blotting with antigens from droppings of two pigeon and budgerigar strains and two hen species. When the antigens from the droppings of the three bird species were compared, the profile of immunogenic proteins was different and there were similarities between strains of the same species. Only one 68-kD protein was common to pigeon and budgerigar droppings, while proteins of 200, 175, 140, 100, and 35 kD were detected as specific in one bird species. These results provide insight to further characterize these proteins, and to design new serological tests specific to different bird species. These tests may help to refine strategies of antigenic exclusion and also to allow a patient compensation in case of BFL of occupational origin.

  9. Freeze-frame fruit selection by birds

    Science.gov (United States)

    Foster, Mercedes S.

    2008-01-01

    The choice of fruits by an avian frugivore is affected by choices it makes at multiple hierarchical levels (e.g., species of fruit, individual tree, individual fruit). Factors that influence those choices vary among levels in the hierarchy and include characteristics of the environment, the tree, and the fruit itself. Feeding experiments with wild-caught birds were conducted at El Tirol, Departamento de Itapua, Paraguay to test whether birds were selecting among individual fruits based on fruit size. Feeding on larger fruits, which have proportionally more pulp, is generally more efficient than feeding on small fruits. In trials (n = 56) with seven species of birds in four families, birds selected larger fruits 86% of the time. However, in only six instances were size differences significant, which is likely a reflection of small sample sizes.

  10. The function of migratory bird calls

    DEFF Research Database (Denmark)

    Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye

    The function of migratory bird calls: do they influence orientation and navigation?   Thomas Reichl1, Bent Bach Andersen2, Ole Naesbye Larsen2, Henrik Mouritsen1   1Institute of Biology, University of Oldenburg, Oldenburg, D-26111 Oldenburg, Germany 2Institute of Biology, University of Southern...... migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...... the experimental bird could be activated successively to simulate a migrating Robin cruising E-W, W-E, S-N or N-S at a chosen height (mostly about 40 m), at 10 m/s and emitting Robin flight calls of 80 dB(A) at 1 m. The simulated flight of a "ding" sound served as a control. During an experiment the bird was first...

  11. [Birds' sense of direction].

    Science.gov (United States)

    Hohtola, Esa

    2016-01-01

    Birds utilize several distinct sensory systems in a flexible manner in their navigation. When navigating with the help of landmarks, location of the sun and stars, or polarization image of the dome of the sky, they resort to vision. The significance of olfaction in long-range navigation has been under debate, even though its significance in local orientation is well documented. The hearing in birds extends to the infrasound region. It has been assumed that they are able to hear the infrasounds generated in the mountains and seaside and navigate by using them. Of the senses of birds, the most exotic one is the ability to sense magnetic fields of the earth.

  12. Oxyspiruriasis in zoo birds.

    Science.gov (United States)

    Vellayan, S; Jeffery, J; Oothuman, P; Zahedi, M; Krishnasamy, M; Paramaswaran, S; Rohela, M; Abdul-Aziz, N M

    2012-06-01

    Oxyspiruriasis caused by the bird eyeworm, Oxyspirura mansoni, a thelaziid nematode, in three species of pheasants, 3 Chrysolophus pictus (golden pheasant), 7 Lophura nycthemera (silver pheasant) and 9 Phasianus colchicus (common pheasant) in Zoo Negara Malaysia are reported. Birds with the disease were treated with a solution of 0.5% iodine or 0.5% lysol. Antistress powder for 4 days in water and non-strep vitamin powder in water was also provided. Control measures included removal of the cockroach intermediate host, Pycnoscelus surinamensis (Surinam cockroach) from the vicinity of the birds. The golden pheasant is a new host for O. mansoni in peninsular Malaysia.

  13. Status of geochemical modeling of groundwater evolution at the Tono in-situ tests site, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Sasamoto, Hiroshi; Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai Works, Tokai, Ibaraki (Japan); Arthur, R.C. [Monitor Scientific, L.L.C., Denver, Colorado (United States)

    1999-12-01

    Hydrochemical investigation of Tertiary sedimentary rocks at JNC's Tono in-situ tests site indicate the groundwaters are: meteoric in origin, chemically reducing at depths greater than a few tens of meters in the sedimentary rock, relatively old [carbon-14 ages of groundwaters collected from the lower part of the sedimentary sequence range from 13,000 to 15,000 years BP (before present)]. Ca-Na-HCO{sub 3} type solutions near the surface, changing to Na-HCO{sub 3} type groundwaters with increasing depth. The chemical evolution of the groundwaters is modeled assuming local equilibrium for selected mineral-fluid reactions, taking into account the rainwater origin of these solutions. Results suggest it is possible to interpret approximately the 'real' groundwater chemistry (i.e., pH, Eh, total dissolved concentrations of Si, Na, Ca, K, Al, carbonate and sulfate) if the following assumptions are adopted: CO{sub 2} concentration in the gas phase contacting pore solutions in the overlying soil zone=10{sup -1} bar, minerals in the rock zone that control the solubility of respective elements in the groundwater include; chalcedony (Si), albite (Na), kaolinite (Al), calcite (Ca and carbonate), muscovite (K) and pyrite (Eh and sulfate). It is noted, however, that the available field data may not be sufficient to adequately constrain parameters in the groundwater evolution model. In particular, more detailed information characterizing certain site properties (e.g., the actual mineralogy of 'plagioclase', 'clay' and 'zeolite') are needed to improve the model. Alternative conceptual models of key reactions may also be necessary. For this reason, a model that accounts for ion-exchange reactions among clay minerals, and which is based on the results of laboratory experiments, has also been evaluated in the present study. Further improvements of model considering ion-exchange reactions are needed in future, however. (author)

  14. A long tailed bird from the Late Cretaceous of Zhejiang

    Institute of Scientific and Technical Information of China (English)

    蔡正全; 赵丽君

    1999-01-01

    A new fossil bird was discovered from the lower part of Upper Cretaceous of Linhai, Zhejiang. With a long tail comprising more than 20 caudal vertebrae, this new brid is morphologically similar to that of Archaeopteryx. Meanwhile, it is similar to Confuciusornis in lacking in teeth. The bird shows the following plesiomorphies besides a long tail: elements of the forelimbs are simple in structure; bones of the manus are separate from one another and two digits are free; abdominal ribs are present. And the new bird shows some apomorphies: The skull bones are lightly built with no teeth; the hindlimbs are better developed than the forelimbs, the articular condyle of the femur is pronouced; the sternum is broad and long; the phalanges and unguals are small, showing its ground-dwelling habit. The fossil bird, coming from the rock of the Late Cretaceous in shouthem China, is very significant to the study of the evolution and relationships of birds.

  15. Birds - Breeding [ds60

    Data.gov (United States)

    California Department of Resources — This data set provides access to information gathered on annual breeding bird surveys in California using a map layer developed by the Department. This data layer...

  16. Awesome Audubon Birds

    Science.gov (United States)

    Kahler, Laura

    2010-01-01

    In this article, the author describes a watercolor art lesson on Audubon birds. She also discusses how science, technology, writing skills, and the elements and principles of art can be incorporated into the lesson.

  17. Partial migration in tropical birds: the frontier of movement ecology.

    Science.gov (United States)

    Sekercioglu, Cagan H

    2010-09-01

    Partial migration, in which only some individuals of a species migrate, might be central to the evolution of migratory behaviour and is likely to represent an evolutionary transition between sedentariness and complete migration. In one of the few detailed, individual-based migration studies of tropical birds, Jahn et al. study the partial migration system of a South American bird species for the first time. Food limitation forces the large adult males and small, young females to migrate, contrary to the expectations of the body size and dominance hypotheses. This study confirms the importance of food variability as the primary driver of migratory behaviour. There is urgent need for similar studies on the movement ecology of understudied tropical bird species, whose diversity of migratory behaviour can shed light on the evolution of bird migration.

  18. A Clever Bird

    Institute of Scientific and Technical Information of China (English)

    徐芳; 孙菊

    2008-01-01

    @@ 一、故事内容 It is getting hotter and hotter day by day.So the birds don't often fly in the sky in daytime.They usually fly in the evening to look for food.But a bird named Polly is very naughty.He just knows how to fly,so he wants to fly every day.One day,when he is flying in the forest,he feels very thirsty.

  19. Complex evolutionary trajectories of sex chromosomes across bird taxa

    DEFF Research Database (Denmark)

    Zhou, Qi; Zhang, Jilin; Bachtrog, Doris

    2014-01-01

    Sex-specific chromosomes, like the W of most female birds and the Y of male mammals, usually have lost most genes owing to a lack of recombination.We analyze newly available genomes of 17 bird species representing the avian phylogenetic range, and find that more than half of them do not have...... strata. Overall, we unveil a complex history of avian sex chromosome evolution....

  20. Phylogeny mandalas of birds using the lithographs of John Gould's folio bird books.

    Science.gov (United States)

    Hasegawa, Masami; Kuroda, Sayako

    2016-12-09

    The phylogeny mandala, which is a circular phylogeny with photos or drawings of species, is a suitable way to show visually how the biodiversity has developed in the course of evolution as clarified by the molecular phylogenetics. In this article, in order to demonstrate the recent progress of avian molecular phylogenetics, six phylogeny mandalas of various taxonomic groups of birds are presented with the lithographs of John Gould's folio bird books; i.e., (1) whole Aves, (2) Passeriformes, (3) Paradisaeidae in Corvoidea (Passeriformes), (4) Meliphagoidea (Passeriformes), (5) Trochili in Apodiformes, and (6) Galliformes.

  1. Evaluation of the Bird Conservation Area Concept in the Northern Tallgrass Prairie : Annual Report: 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1998 we initiated a test of the concept that Bird Conservation Areas (BCA's) can maintain populations of breeding grassland birds. The underlying hypothesis is...

  2. Parasites and mutational load: an experimental test of a pluralistic theory for the evolution of sex

    Science.gov (United States)

    Cooper, Tim F.; Lenski, Richard E.; Elena, Santiago F.

    2005-01-01

    Ecological and mutational explanations for the evolution of sexual reproduction have usually been considered independently. Although many of these explanations have yielded promising theoretical results, experimental support for their ability to overcome a twofold cost of sex has been limited. For this reason, it has recently been argued that a pluralistic approach, combining effects from multiple models, may be necessary to explain the apparent advantage of sex. One such pluralistic model proposes that parasite load and synergistic epistasis between deleterious mutations might interact to create an advantage for recombination. Here, we test this proposal by comparing the fitness functions of parasitized and parasite-free genotypes of Escherichia coli bearing known numbers of transposon-insertion mutations. In both classes, we failed to detect any evidence for synergistic epistasis. However, the average effect of deleterious mutations was greater in parasitized than parasite-free genotypes. This effect might broaden the conditions under which another proposed model combining parasite–host coevolutionary dynamics and mutation accumulation can explain the maintenance of sex. These results suggest that, on average, deleterious mutations act multiplicatively with each other but in synergy with infection in determining fitness. PMID:15705557

  3. EMPIRICAL WEIGHTED MODELLING ON INTER-COUNTY INEQUALITIES EVOLUTION AND TO TEST ECONOMICAL CONVERGENCE IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Natalia\tMOROIANU‐DUMITRESCU

    2015-06-01

    Full Text Available During the last decades, the regional convergence process in Europe has attracted a considerable interest as a highly significant issue, especially after EU enlargement with the New Member States from Central and Eastern Europe. The most usual empirical approaches are using the β- and σ-convergence, originally developed by a series of neo-classical models. Up-to-date, the EU integration process was proven to be accompanied by an increase of the regional inequalities. In order to determine the existence of a similar increase of the inequalities between the administrative counties (NUTS3 included in the NUTS2 and NUTS1 regions of Romania, this paper provides an empirical modelling of economic convergence allowing to evaluate the level and evolution of the inter-regional inequalities over more than a decade period lasting from 1995 up to 2011. The paper presents the results of a large cross-sectional study of σ-convergence and weighted coefficient of variation, using GDP and population data obtained from the National Institute of Statistics of Romania. Both graphical representation including non-linear regression and the associated tables summarizing numerical values of the main statistical tests are demonstrating the impact of pre- accession policy on the economic development of all Romanian NUTS types. The clearly emphasised convergence in the middle time subinterval can be correlated with the pre-accession drastic changes on economic, political and social level, and with the opening of the Schengen borders for Romanian labor force in 2002.

  4. Evolution of viviparity in warm-climate lizards: an experimental test of the maternal manipulation hypothesis.

    Science.gov (United States)

    Ji, X; Lin, C-X; Lin, L-H; Qiu, Q-B; DU, Y

    2007-05-01

    The maternal manipulation hypothesis for the evolution of reptilian viviparity has been claimed to apply to any situation where gravid females are able to maintain body temperatures different from those available in external nests, but empirical data that support this hypothesis are very limited. Here, we tested this hypothesis using gravid females of a warm-climate lizard, Mabuya multifasciata, by subjecting them to five thermal regimes for the whole gestation period. We found gravid females selected lower body temperatures and thermoregulated more precisely than did nongravid females. Offspring produced in different treatments differed in head size, limb length and sprint speed, but not in overall body size or mass. Variation in morphological traits of offspring was induced primarily by extreme temperatures. Sprint speed of offspring was more likely affected by the mean but not by the variance of gestation temperatures. Gravid females maintained more stable body temperatures than did nongravid females not because these temperatures resulted in the optimization of offspring phenotypes but because the range of temperatures optimal for embryonic development was relatively narrow. Our data conform to the main predictions from the maternal manipulation hypothesis that females should adjust thermoregulation during pregnancy to provide optimal thermal conditions for developing embryos and that phenotypic traits forged by maternal thermoregulation should enhance offspring fitness.

  5. Malarial parasites decrease reproductive success: an experimental study in a passerine bird.

    Science.gov (United States)

    Marzal, Alfonso; de Lope, Florentino; Navarro, Carlos; Møller, Anders Pape

    2005-02-01

    Malarial parasites are supposed to have strong negative fitness consequences for their hosts, but relatively little evidence supports this claim due to the difficulty of experimentally testing this. We experimentally reduced levels of infection with the blood parasite Haemoproteus prognei in its host the house martin Delichon urbica, by randomly treating adults with primaquine or a control treatment. Treated birds had significantly fewer parasites than controls. The primaquine treatment increased clutch size by 18%; hatching was 39% higher and fledging 42% higher. There were no effects of treatment on quality of offspring, measured in terms of tarsus length, body mass, haematocrit or T-cell-mediated immune response. These findings demonstrate that malarial parasites can have dramatic effects on clutch size and other demographic variables, potentially influencing the evolution of clutch size, but also the population dynamics of heavily infected populations of birds.

  6. Sindbis Virus Infection in Resident Birds, Migratory Birds, and Humans, Finland

    OpenAIRE

    Kurkela, Satu; Rätti, Osmo; Huhtamo, Eili; Uzcátegui, Nathalie Y.; Nuorti, J. Pekka; Laakkonen, Juha; Manni, Tytti; Helle, Pekka; Vaheri, Antti; Vapalahti, Olli

    2008-01-01

    Sindbis virus (SINV), a mosquito-borne virus that causes rash and arthritis, has been causing outbreaks in humans every seventh year in northern Europe. To gain a better understanding of SINV epidemiology in Finland, we searched for SINV antibodies in 621 resident grouse, whose population declines have coincided with human SINV outbreaks, and in 836 migratory birds. We used hemagglutination-inhibition and neutralization tests for the bird samples and enzyme immunoassays and hemagglutination-i...

  7. Rapid sympatry explains greater color pattern divergence in high latitude birds.

    Science.gov (United States)

    Martin, Paul R; Montgomerie, Robert; Lougheed, Stephen C

    2010-02-01

    Latitudinal variation in patterns of evolution has fascinated biologists for over a century, but our understanding of latitudinal differences in evolutionary processes-such as selection and drift-remains limited. Here, we test for, and find, accelerated evolution of color patterns in bird taxa that breed at higher latitudes compared with those breeding in the tropics, analyzing data from seven diverse avian families. Most important, we show that the extent of overlap of species' breeding ranges (degree of sympatry) explains the elevated rate of color pattern evolution at higher latitudes. We suggest that the dynamic shifts in breeding ranges that accompanied climatic changes during the last 3 million years (Milankovitch Oscillations) resulted in more rapid and more frequent secondary contact at high latitudes. We argue that sympatry among diverging clades causes greater divergence of color traits in birds at higher latitudes through sexual, social, or ecological character displacement that accelerate rates of evolution, and through the selective elimination of weakly differentiated lineages that hybridize and fuse in sympatry (differential fusion).

  8. Epidemiological study of Chlamydophila psittaci in pet birds in Croatia

    Directory of Open Access Journals (Sweden)

    Križek I.

    2012-01-01

    Full Text Available A total of 411 samples from birds of different species originating from all counties of the Republic of Croatia have been tested for the presence of Chlamydophila psittaci. The sampling was conducted in pet stores, breeders' aviaries, in a specialized bird clinic and in zoos. The testing included 177 parrots, 169 pigeons, 58 canaries and 7 finches. For the detection of specific C. psittaci antigen a commercial ELISA kit was used- IDEIATM PCE Chlamydia (DAKO Cytomation Ltd., United Kingdom. The samples that were non-specifically positive or doubtful in the ELISA test (a total of 26 samples were analyzed also by means of polymerase chain reaction (PCR. Diagnostic ELISA method found a total of 17.03% birds positive for chlamydiosis, and after additional testing by PCR a total of 12.65% positive ones were found. According to bird species, the most frequently positive ones were canaries and pigeons (15.52% and 13.02%, and according to the sampling location most of the positive birds were found in pet stores (16.52%, but a high percentage of positive samples were also found in breeders’ aviaries (11.76%. The average positive result for chlamydiosis in 12.65% of tested birds is alarming and it confirms the importance of monitoring bird health and of prescribed legal regulations when it comes to chlamydial diseases, as well as education of persons involved in breeding, keeping or selling birds.

  9. MOXD2, a Gene Possibly Associated with Olfaction, Is Frequently Inactivated in Birds.

    Science.gov (United States)

    Goh, Chul Jun; Choi, Dongjin; Park, Dong-Bin; Kim, Hyein; Hahn, Yoonsoo

    2016-01-01

    Vertebrate MOXD2 encodes a monooxygenase DBH-like 2 protein that could be involved in neurotransmitter metabolism, potentially during olfactory transduction. Loss of MOXD2 in apes and whales has been proposed to be associated with evolution of olfaction in these clades. We analyzed 57 bird genomes to identify MOXD2 sequences and found frequent loss of MOXD2 in 38 birds. Among the 57 birds, 19 species appeared to have an intact MOXD2 that encoded a full-length protein; 32 birds had a gene with open reading frame-disrupting point mutations and/or exon deletions; and the remaining 6 species did not show any MOXD2 sequence, suggesting a whole-gene deletion. Notably, among 10 passerine birds examined, 9 species shared a common genomic deletion that spanned several exons, implying the gene loss occurred in a common ancestor of these birds. However, 2 closely related penguin species, each of which had an inactive MOXD2, did not share any mutation, suggesting an independent loss after their divergence. Distribution of the 38 birds without an intact MOXD2 in the bird phylogenetic tree clearly indicates that MOXD2 loss is widespread and independent in bird lineages. We propose that widespread MOXD2 loss in some bird lineages may be implicated in the evolution of olfactory perception in these birds.

  10. Historical Evolution of NASA Standard Materials Testing with Hypergolic Propellants and Ammonia (NASA Standard 6001 Test 15)

    Science.gov (United States)

    Greene, Benjamin; McClure, Mark B.

    2012-01-01

    The NASA Johnson Space Center White Sands Test Facility (WSTF) has performed testing of hazardous and reactive aerospace fluids, including hypergolic propellants, with materials since the 1960s with the Apollo program. Amongst other test activities, Test 15 is a NASA standard test for evaluating the reactivity of materials with selected aerospace fluids, in particular hydrazine, monomethylhydrazine, uns-dimethylhydrazine, Aerozine 50, dinitrogen tetroxide oxidizers, and ammonia. This manuscript provides an overview of the history of Test 15 over a timeline ranging from prior to its development and first implementation as a NASA standard test in 1974 to its current refinement. Precursor documents to NASA standard tests, as they are currently known, are reviewed. A related supplementary test, international standardization, and enhancements to Test 15 are also discussed. Because WSTF was instrumental in the development and implementation of Test 15, WSTF experience and practices are referred to in this manuscript.

  11. Simulated birdwatchers' playback affects the behavior of two tropical birds.

    Directory of Open Access Journals (Sweden)

    J Berton C Harris

    Full Text Available Although recreational birdwatchers may benefit conservation by generating interest in birds, they may also have negative effects. One such potentially negative impact is the widespread use of recorded vocalizations, or "playback," to attract birds of interest, including range-restricted and threatened species. Although playback has been widely used to test hypotheses about the evolution of behavior, no peer-reviewed study has examined the impacts of playback in a birdwatching context on avian behavior. We studied the effects of simulated birdwatchers' playback on the vocal behavior of Plain-tailed Wrens Thryothorus euophrys and Rufous Antpittas Grallaria rufula in Ecuador. Study species' vocal behavior was monitored for an hour after playing either a single bout of five minutes of song or a control treatment of background noise. We also studied the effects of daily five minute playback on five groups of wrens over 20 days. In single bout experiments, antpittas made more vocalizations of all types, except for trills, after playback compared to controls. Wrens sang more duets after playback, but did not produce more contact calls. In repeated playback experiments, wren responses were strong at first, but hardly detectable by day 12. During the study, one study group built a nest, apparently unperturbed, near a playback site. The playback-induced habituation and changes in vocal behavior we observed suggest that scientists should consider birdwatching activity when selecting research sites so that results are not biased by birdwatchers' playback. Increased vocalizations after playback could be interpreted as a negative effect of playback if birds expend energy, become stressed, or divert time from other activities. In contrast, the habituation we documented suggests that frequent, regular birdwatchers' playback may have minor effects on wren behavior.

  12. Simulated birdwatchers' playback affects the behavior of two tropical birds.

    Science.gov (United States)

    Harris, J Berton C; Haskell, David G

    2013-01-01

    Although recreational birdwatchers may benefit conservation by generating interest in birds, they may also have negative effects. One such potentially negative impact is the widespread use of recorded vocalizations, or "playback," to attract birds of interest, including range-restricted and threatened species. Although playback has been widely used to test hypotheses about the evolution of behavior, no peer-reviewed study has examined the impacts of playback in a birdwatching context on avian behavior. We studied the effects of simulated birdwatchers' playback on the vocal behavior of Plain-tailed Wrens Thryothorus euophrys and Rufous Antpittas Grallaria rufula in Ecuador. Study species' vocal behavior was monitored for an hour after playing either a single bout of five minutes of song or a control treatment of background noise. We also studied the effects of daily five minute playback on five groups of wrens over 20 days. In single bout experiments, antpittas made more vocalizations of all types, except for trills, after playback compared to controls. Wrens sang more duets after playback, but did not produce more contact calls. In repeated playback experiments, wren responses were strong at first, but hardly detectable by day 12. During the study, one study group built a nest, apparently unperturbed, near a playback site. The playback-induced habituation and changes in vocal behavior we observed suggest that scientists should consider birdwatching activity when selecting research sites so that results are not biased by birdwatchers' playback. Increased vocalizations after playback could be interpreted as a negative effect of playback if birds expend energy, become stressed, or divert time from other activities. In contrast, the habituation we documented suggests that frequent, regular birdwatchers' playback may have minor effects on wren behavior.

  13. Replaying Evolution to Test the Cause of Extinction of One Ecotype in an Experimentally Evolved Population.

    Directory of Open Access Journals (Sweden)

    Caroline B Turner

    Full Text Available In a long-term evolution experiment with Escherichia coli, bacteria in one of twelve populations evolved the ability to consume citrate, a previously unexploited resource in a glucose-limited medium. This innovation led to the frequency-dependent coexistence of citrate-consuming (Cit+ and non-consuming (Cit- ecotypes, with Cit-bacteria persisting on the exogenously supplied glucose as well as other carbon molecules released by the Cit+ bacteria. After more than 10,000 generations of coexistence, however, the Cit-lineage went extinct; cells with the Cit-phenotype dropped to levels below detection, and the Cit-clade could not be detected by molecular assays based on its unique genotype. We hypothesized that this extinction was a deterministic outcome of evolutionary change within the population, specifically the appearance of a more-fit Cit+ ecotype that competitively excluded the Cit-ecotype. We tested this hypothesis by re-evolving the population from a frozen population sample taken within 500 generations of the extinction and from another sample taken several thousand generations earlier, in each case for 500 generations and with 20-fold replication. To our surprise, the Cit-type did not go extinct in any of these replays, and Cit-cells also persisted in a single replicate that was propagated for 2,500 generations. Even more unexpectedly, we showed that the Cit-ecotype could reinvade the Cit+ population after its extinction. Taken together, these results indicate that the extinction of the Cit-ecotype was not a deterministic outcome driven by competitive exclusion by the Cit+ ecotype. The extinction also cannot be explained by demographic stochasticity alone, as the population size of the Cit-ecotype should have been many thousands of cells even during the daily transfer events. Instead, we infer that the extinction must have been caused by a rare chance event in which some aspect of the experimental conditions was inadvertently perturbed.

  14. Controls on stream network branching angles, tested using landscape evolution models

    Science.gov (United States)

    Theodoratos, Nikolaos; Seybold, Hansjörg; Kirchner, James W.

    2016-04-01

    Stream networks are striking landscape features. The topology of stream networks has been extensively studied, but their geometry has received limited attention. Analyses of nearly 1 million stream junctions across the contiguous United States [1] have revealed that stream branching angles vary systematically with climate and topographic gradients at continental scale. Stream networks in areas with wet climates and gentle slopes tend to have wider branching angles than in areas with dry climates or steep slopes, but the mechanistic linkages underlying these empirical correlations remain unclear. Under different climatic and topographic conditions different runoff generation mechanisms and, consequently, transport processes are dominant. Models [2] and experiments [3] have shown that the relative strength of channel incision versus diffusive hillslope transport controls the spacing between valleys, an important geometric property of stream networks. We used landscape evolution models (LEMs) to test whether similar factors control network branching angles as well. We simulated stream networks using a wide range of hillslope diffusion and channel incision parameters. The resulting branching angles vary systematically with the parameters, but by much less than the regional variability in real-world stream networks. Our results suggest that the competition between hillslope and channeling processes influences branching angles, but that other mechanisms may also be needed to account for the variability in branching angles observed in the field. References: [1] H. Seybold, D. H. Rothman, and J. W. Kirchner, 2015, Climate's watermark in the geometry of river networks, Submitted manuscript. [2] J. T. Perron, W. E. Dietrich, and J. W. Kirchner, 2008, Controls on the spacing of first-order valleys, Journal of Geophysical Research, 113, F04016. [3] K. E. Sweeney, J. J. Roering, and C. Ellis, 2015, Experimental evidence for hillslope control of landscape scale, Science, 349

  15. Orientation in birds. Olfactory navigation.

    Science.gov (United States)

    Papi, F

    1991-01-01

    Research work on the olfactory navigation of birds, which has only recently attracted attention, has shown that many wild species rely on an osmotactic mechanism to find food sources, even at a considerable distance. The homing pigeon, the only bird to have been thoroughly investigated with respect to olfactory navigation, has been found to rely on local odours for homeward orientation, and to integrate olfactory cues perceived during passive transportation with those picked up at the release site. It is possible to design experiments in which birds are given false olfactory information, and predictions about the effects of this can be made and tested. Pigeons are able to home from unfamiliar sites because they acquire an olfactory map extending beyond the area they have flown over. The olfactory map is built up by associating wind-borne odours with the direction from which they come; this was shown by experiments which aimed to prevent, limit or alter this association. One aim of the research work has been to test whether pigeons flying over unfamiliar areas also rely or can learn to rely on non-olfactory cues, depending on their local availability, and/or on the methods of rearing and training applied to them. Various evaluations have been made of the results; the most recent experiments, however, confirm that pigeons do derive directional information from atmospheric odours. A neurobiological approach is also in progress; its results show that some telencephalic areas are involved in orientation and olfactory navigation. The lack of any knowledge about the distribution and chemical nature of the odorants which allow pigeons to navigate hinders progress in this area of research.

  16. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    Migratory movements of birds has always fascinated man and led to many questions concerning the ecological drivers behind, the necessary adaptations and the navigational abilities required. However, especially for the long-distance migrants, basic descriptions of their movements are still lacking...... and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements...... in when and where the bird compensated for the displacement. The last paper investigates effects of habitat shading on the performance of light-level based geolocation and compares experimental data with data from real tracking studies. This illustrates some of the potential problems and limitations...

  17. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  18. Bird pollination of Canary Island endemic plants

    Science.gov (United States)

    Ollerton, Jeff; Cranmer, Louise; Stelzer, Ralph J.; Sullivan, Steve; Chittka, Lars

    2009-02-01

    The Canary Islands are home to a guild of endemic, threatened bird-pollinated plants. Previous work has suggested that these plants evolved floral traits as adaptations to pollination by flower specialist sunbirds, but subsequently, they appear to have co-opted generalist passerine birds as sub-optimal pollinators. To test this idea, we carried out a quantitative study of the pollination biology of three of the bird-pollinated plants, Canarina canariensis (Campanulaceae), Isoplexis canariensis (Veronicaceae) and Lotus berthelotii (Fabaceae), on the island of Tenerife. Using colour vision models, we predicted the detectability of flowers to bird and bee pollinators. We measured pollinator visitation rates, nectar standing crops as well as seed-set and pollen removal and deposition. These data showed that the plants are effectively pollinated by non-flower specialist passerine birds that only occasionally visit flowers. The large nectar standing crops and extended flower longevities (>10 days) of Canarina and Isoplexis suggests that they have evolved a bird pollination system that effectively exploits these low frequency non-specialist pollen vectors and is in no way sub-optimal. Seed set in two of the three species was high and was significantly reduced or zero in flowers where pollinator access was restricted. In L. berthelotii, however, no fruit set was observed, probably because the plants were self-incompatible horticultural clones of a single genet. We also show that, while all three species are easily detectable for birds, the orange Canarina and the red Lotus (but less so the yellow-orange Isoplexis) should be difficult to detect for insect pollinators without specialised red receptors, such as bumblebees. Contrary to expectations if we accept that the flowers are primarily adapted to sunbird pollination, the chiffchaff ( Phylloscopus canariensis) was an effective pollinator of these species.

  19. Chinese and Foreign Bird Lovers Watch Birds in Deyang

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>Invited by the Sichuan Provincial People’s Association for Friendship with Foreign Countries (SIFA) and the Chengdu Bird Watching Society, 60 Chinese and foreign bird lovers went to Deyang, a city in Sichuan Province that had suffered grave damages in the Wenchuan earthquake, to watch birds,

  20. Effect of endosulfan on immunological competence of layer birds

    Science.gov (United States)

    Singh, P. P.; Kumar, Ashok; Chauhan, R. S.; Pankaj, P. K.

    2016-01-01

    Aim: The present study was aimed to investigate the immunological competence of endosulfan insecticide after limited oral administration in White Leghorn layer chickens. Materials and Methods: A total of 20 White Leghorn birds were given endosulfan in drinking water at 30 ppm/bird/day (no observable effect level dose) for a period of 3-months. Immune competence status of layer birds and chicks hatched from endosulfan offered birds were estimated at 15-day interval in layer birds and at monthly interval in chicks using immunological, biochemical parameters, and teratological estimates. Results: There was a significant decrease in levels of total leukocytes count, absolute lymphocyte count, absolute heterophil count, total serum protein, serum albumin, serum globulin, and serum gamma globulin in the birds fed with endosulfan as compared to control. Similarly, immune competence tests such as lymphocyte stimulation test, oxidative burst assay, and enzyme-linked immunosorbent assay tests indicated lower immunity in birds treated with endosulfan as compared to control. Subsequently, chicks produced from endosulfan-treated birds were also examined for immune competence, but no significant difference was observed between chicks of both the groups. Conclusion: The exposure to endosulfan in limited oral dosage was able to exhibit hemo-biochemical and other changes that could be correlated with changes in the immunological profile of layer chickens suggesting cautious usage of endosulfan insecticide in poultry sheds. PMID:27536042

  1. Tropical birds have a slow pace of life.

    Science.gov (United States)

    Wiersma, Popko; Muñoz-Garcia, Agustí; Walker, Amy; Williams, Joseph B

    2007-05-29

    Tropical birds are relatively long-lived and produce few offspring, which develop slowly and mature relatively late in life, the slow end of the life-history axis, whereas temperate birds lie at the opposite end of this continuum. We tested the hypothesis that tropical birds have evolved a reduced basal metabolic rate (BMR). We measured BMR of 69 species of tropical birds, the largest data set amassed on metabolic rates of tropical birds, and compared these measurements with 59 estimates of BMR for temperate birds. Our analyses included conventional least squares regression, regressions based on phylogenetic independent contrasts, and a comparison of BMR of 13 phylogenetically matched pairs, one species from the tropics and one from northerly temperate areas. Our triptych showed that tropical birds had a reduced BMR, compelling evidence for a connection between the life history of tropical birds and a slow pace of life. Further, tropical migrants breeding in temperate habitats had a lower BMR than did temperate residents, suggesting that these migrants have physiological traits consistent with a slow pace of life. In addition, we determined that tropical birds had a lower cold-induced peak metabolic rate and thermogenic metabolic scope than temperate species, a finding that is consistent with the hypothesis that their environment has not selected for high levels of thermogenesis, or alternatively, that a slow pace of life may be incompatible with high thermogenic capacity. We conclude that physiological function correlates with the suite of life-history traits.

  2. Diversity in olfactory bulb size in birds reflects allometry, ecology and phylogeny

    Directory of Open Access Journals (Sweden)

    Jeremy Richard Corfield

    2015-07-01

    Full Text Available The relative size of olfactory bulbs is correlated with olfactory capabilities across vertebrates and is widely used to assess the relative importance of olfaction to a species’ ecology. In birds, variations in the relative size of olfactory bulbs are correlated with some behaviors, however, the factors that have led to the high level of diversity seen in olfactory bulb sizes across birds are still not well understood. In this study, we use the relative size of olfactory bulbs as a neuroanatomical proxy for olfactory capabilities in 135 species of birds, representing 21 orders. We examine the scaling of olfactory bulbs with brain size across avian orders, determined likely ancestral states and test for correlations between OB sizes and habitat, ecology and behavior. The size of avian OBs varied with the size of the brain and this allometric relationship was for the most part isometric, although species did deviate from this trend. Large olfactory bulbs were characteristic of more basal species and in more recently derived species the OBs were small. Living and foraging in a semi aquatic environment was the strongest variable driving the evolution of large olfactory bulbs in birds; olfaction may provide cues for navigation and foraging in this otherwise featureless environment. Some of the diversity in OB sizes was also undoubtedly due to differences in migratory behavior, foraging strategies and social structure. In summary, relative OB size in birds reflect allometry, phylogeny and behavior in ways that parallel that of other vertebrate classes. This provides comparative evidence that supports recent experimental studies into avian olfaction and suggests that olfaction is a critically important sensory modality for all avian species.

  3. Are Birds a Manace to Outdoor Monuments?

    Directory of Open Access Journals (Sweden)

    Adrian Vasiliu

    2010-06-01

    Full Text Available Preliminary results of laboratory tests on real samples have shown that the uric acid which is found in bird droppings has a negative influence on metals. Results of experiments have confirmed that the damage is significant when considering the cultural heritage, statues or monuments.

  4. Local predation pressure predicts the strength of mobbing responses in tropical birds

    Institute of Scientific and Technical Information of China (English)

    Luis SANDOVAL; David R.WILSON

    2012-01-01

    Many birds join cooperative mobbing aggregations and collectively harass predators.Individuals participating in these ephemeral associations benefit by deterring the predator,but also incur energetic costs and increased risk of predation.Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob.An important step in understanding the evolution of mobbing is to identify factors affecting its expression.The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions,such as when local predation pressure is high.We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator,the ferruginous pygmy-owl Glaucidium brasilianum.We used acoustic playback to elicit mobbing responses in environments where owls were common,uncommon,or rare.Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl's common prey species.During each playback,we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker,as well as the closest approach by any bird.Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common,intermediate where owls were uncommon,and weak where they were rare.This pattern persisted even after controlling for differences in species richness and composition among the three environments.Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds.

  5. Local predation pressure predicts the strength of mobbing responses in tropical birds

    Directory of Open Access Journals (Sweden)

    Luis SANDOVAL, David R. WILSON

    2012-10-01

    Full Text Available Many birds join cooperative mobbing aggregations and collectively harass predators. Individuals participating in these ephemeral associations benefit by deterring the predator, but also incur energetic costs and increased risk of predation. Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob. An important step in understanding the evolution of mobbing is to identify factors affecting its expression. The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions, such as when local predation pressure is high. We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator, the ferruginous pygmy-owl Glaucidium brasilianum. We used acoustic playback to elicit mobbing responses in environments where owls were common, uncommon, or rare. Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl’s common prey species. During each playback, we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker, as well as the closest approach by any bird. Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common, intermediate where owls were uncommon, and weak where they were rare. This pattern persisted even after controlling for differences in species richness and composition among the three environments. Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds [Current Zoology 58 (5: 781-790, 2012].

  6. Synanthropic birds and parasites.

    Science.gov (United States)

    Dipineto, Ludovico; Borrelli, Luca; Pepe, Paola; Fioretti, Alessandro; Caputo, Vincenzo; Cringoli, Giuseppe; Rinaldi, Laura

    2013-12-01

    This paper describes the parasitologic findings for 60 synanthropic bird carcasses recovered in the Campania region of southern Italy. Birds consisted of 20 yellow-legged gulls (Larus michahellis), 15 rock pigeons (Columba livia), 15 common kestrels (Falco tinnunculus), and 10 carrion crows (Corvus corone). Each carcass was examined to detect the presence of ectoparasites and then necropsied to detect helminths. Ectoparasites occurred in 100% of the birds examined. In particular, chewing lice were recovered with a prevalence of 100%, whereas Pseudolynchia canariensis (Hippoboscidae) were found only in pigeons with a prevalence of 80%. Regarding endoparasites, a total of seven helminth species were identified: three nematodes (Ascaridia columbae, Capillaria columbae, Physaloptera alata), one cestoda (Raillietina tetragona), one trematoda (Cardiocephalus longicollis), and two acanthocephalans (Centrorhynchus globocaudatus and Centrorhynchus buteonis). The findings of the present study add data to the parasitologic scenario of synanthropic birds. This is important because parasitic infection can lead to serious health problems when combined with other factors and may affect flying performance and predatory effectiveness.

  7. [Anesthesia in birds].

    Science.gov (United States)

    Grimm, F

    1987-01-01

    Anaesthesia in birds is ordered by law and is also necessary for various operations and manipulations. Anaesthesia by injection of Ketamin, which in special cases may be combined with Diazepam, has been found useful. Anaesthesia by inhalation with Halothan, Methoxyfluran or Isofluran is the most careful method. Local anaesthesia has few indications.

  8. Attracting Birds to Your Backyard.

    Science.gov (United States)

    Joyce, Brian

    1994-01-01

    Discusses methods for drawing birds to outdoor education areas, including the use of wild and native vegetation. Lists specific garden plants suitable for attracting birds in each season. Includes a guide to commercial bird seed and instructions for building homemade birdfeeders and nestboxes. (LZ)

  9. Birds of Prey of Wisconsin.

    Science.gov (United States)

    Hamerstrom, Frances

    This copiously illustrated document is designed to be a field quide to birds of prey that are common to Wisconsin, as well as to some that enter the state occasionally. An introduction discusses birds of prey with regard to migration patterns, the relationship between common names and the attitudes of people toward certain birds, and natural signs…

  10. Birds and wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Langston, Rowena

    2011-07-01

    Full text: Climate change, perhaps more accurately described as climate disruption, is considered to be a major long-term threat to biodiversity, with a high probability that the underlying cause is due to anthropogenic greenhouse gas emissions. Renewable energy is an important component of a programme of measures to combat further climate change, to include improved energy efficiency and demand management. Wind energy is the most advanced renewable energy source and is a global industry onshore and, increasingly, offshore. However, as with any form of energy generation, wind energy also has potential environmental costs which have to be balanced against benefits. The environmental impacts on birds derive from the following: collision risk, in particular from the moving rotor blades; displacement arising from disturbance during construction, operation or decommissioning; habitat loss or change leading to alteration of food availability; barrier effects leading to deviation of long distance migratory flights or disruption of local flights between feeding, nesting, and roosting/loafing locations. Not all species of birds, or individuals within a species, are equally susceptible to negative interactions with wind turbines, and neither are the population consequences of impacts equivalent. Of greatest concern are bird species of conservation concern that exhibit behaviours that place them at risk of an adverse impact, notably when that impact leads to a reduction in population size that is unlikely to be compensated for. In particular, cumulative impacts arising from multiple wind farms or wind farms in combination with other developments are of concern. There has been a welcome increase in research effort and peer-reviewed publications on the subject of birds and wind energy in recent years. Increasing our understanding of impacts is essential to delivering possible solutions and this paper reviews current knowledge for birds. (Author)

  11. Damage evolution in GLARE fibre-metal laminate under repeated low-velocity impact tests

    NARCIS (Netherlands)

    Morinière, F.D.; Alderliesten, R.C.; Tooski, M.Y.; Benedictus, R.

    2012-01-01

    An experimental study was performed on the repeated low-velocity impact behaviour of GLARE. Damage evolution in the material constituents was characterised with successive number of impacts. Records were correlated with visual inspection, ultrasound C-scan and chemical etching. The stiffness of the

  12. The erratic mitochondrial clock: variations of mutation rate, not population size, affect mtDNA diversity across birds and mammals

    Directory of Open Access Journals (Sweden)

    Galtier Nicolas

    2009-03-01

    Full Text Available Abstract Background During the last ten years, major advances have been made in characterizing and understanding the evolution of mitochondrial DNA, the most popular marker of molecular biodiversity. Several important results were recently reported using mammals as model organisms, including (i the absence of relationship between mitochondrial DNA diversity and life-history or ecological variables, (ii the absence of prominent adaptive selection, contrary to what was found in invertebrates, and (iii the unexpectedly large variation in neutral substitution rate among lineages, revealing a possible link with species maximal longevity. We propose to challenge these results thanks to the bird/mammal comparison. Direct estimates of population size are available in birds, and this group presents striking life-history trait differences with mammals (higher mass-specific metabolic rate and longevity. These properties make birds the ideal model to directly test for population size effects, and to discriminate between competing hypotheses about the causes of substitution rate variation. Results A phylogenetic analysis of cytochrome b third-codon position confirms that the mitochondrial DNA mutation rate is quite variable in birds, passerines being the fastest evolving order. On average, mitochondrial DNA evolves slower in birds than in mammals of similar body size. This result is in agreement with the longevity hypothesis, and contradicts the hypothesis of a metabolic rate-dependent mutation rate. Birds show no footprint of adaptive selection on cytochrome b evolutionary patterns, but no link between direct estimates of population size and cytochrome b diversity. The mutation rate is the best predictor we have of within-species mitochondrial diversity in birds. It partly explains the differences in mitochondrial DNA diversity patterns observed between mammals and birds, previously interpreted as reflecting Hill-Robertson interferences with the W

  13. Eclipsing binary systems as tests of low-mass stellar evolution theory

    CERN Document Server

    Feiden, Gregory A

    2015-01-01

    Stellar fundamental properties (masses, radii, effective temperatures) can be extracted from observations of eclipsing binary systems with remarkable precision, often better than 2%. Such precise measurements afford us the opportunity to confront the validity of basic predictions of stellar evolution theory, such as the mass-radius relationship. A brief historical overview of confrontations between stellar models and data from eclipsing binaries is given, highlighting key results and physical insight that have led directly to our present understanding. The current paradigm that standard stellar evolution theory is insufficient to describe the most basic relation, that of a star's mass to its radius, along the main sequence is then described. Departures of theoretical expectations from empirical data, however, provide a rich opportunity to explore various physical solutions, improving our understanding of important stellar astrophysical processes.

  14. Quantitative Test of the Evolution of Geant4 Electron Backscattering Simulation

    CERN Document Server

    Basaglia, Tullio; Hoff, Gabriela; Kim, Chan Hyeong; Kim, Sung Hun; Pia, Maria Grazia; Saracco, Paolo

    2016-01-01

    Evolutions of Geant4 code have affected the simulation of electron backscattering with respect to previously published results. Their effects are quantified by analyzing the compatibility of the simulated electron backscattering fraction with a large collection of experimental data for a wide set of physics configuration options available in Geant4. Special emphasis is placed on two electron scattering implementations first released in Geant4 version 10.2: the Goudsmit-Saunderson multiple scattering model and a single Coulomb scattering model based on Mott cross section calculation. The new Goudsmit-Saunderson multiple scattering model appears to perform equally or less accurately than the model implemented in previous Geant4 versions, depending on the electron energy. The new Coulomb scattering model was flawed from a physics point of view, but computationally fast in Geant4 version 10.2; the physics correction released in Geant4 version 10.2p01 severely degrades its computational performance. Evolutions in ...

  15. The evolution of hyperboloidal data with the dual foliation formalism: Mathematical analysis and wave equation tests

    CERN Document Server

    Hilditch, David; Bugner, Marcus; Rueter, Hannes; Bruegmann, Bernd

    2016-01-01

    A long-standing problem in numerical relativity is the satisfactory treatment of future null-infinity. We propose an approach for the evolution of hyperboloidal initial data in which the outer boundary of the computational domain is placed at infinity. The main idea is to apply the `dual foliation' formalism in combination with hyperboloidal coordinates and the generalized harmonic gauge formulation. The strength of the present approach is that, following the ideas of Zenginoglu, a hyperboloidal layer can be naturally attached to a central region using standard coordinates of numerical relativity applications. Employing a generalization of the standard hyperboloidal slices, developed by Calabrese et. al., we find that all formally singular terms take a trivial limit as we head to null-infinity. A byproduct is a numerical approach for hyperboloidal evolution of nonlinear wave equations violating the null-condition. The height-function method, used often for fixed background spacetimes, is generalized in such a...

  16. Bird Watching in China

    Institute of Scientific and Technical Information of China (English)

    CHRIS; DEVONSHIRE-ELLIS

    2006-01-01

    Being based in, and conducting business in, some of China's largest cities is an exciting, yet stressful occupation and 1 like to relax by taking a pair of binoculars, getting out into the open air of China's huge countryside, and spending time seeing what birds I can identify. I'm not really a twitcher (one who relentlessly pursues sightings of as many different species as possible)-just happy to get into nature. In my travels around the country, I listed

  17. 3. Bird conservation

    OpenAIRE

    2016-01-01

    Expert assessors Tatsuya Amano, Cambridge University, UK Andy Brown, Natural England, UK Fiona Burns, Royal Society for the Protection of Birds, UK Yohay Carmel, Israel Institute of Technology, Israel Mick Clout, University of Auckland, New Zealand Geoff Hilton, Wildfowl & Wetlands Trust, UK Nancy Ockendon, Cambridge University, UK James Pearce-Higgins, British Trust for Ornithology, UK Sugoto Roy, Food and Environment Research Agency, DEFRA, UK Rebecca Smith, Cambridge University, UK William...

  18. Testosterone in tropical birds: effects of environmental and social factors.

    Science.gov (United States)

    Goymann, Wolfgang; Moore, Ignacio T; Scheuerlein, Alexander; Hirschenhauser, Katharina; Grafen, Alan; Wingfield, John C

    2004-09-01

    Previous investigations suggest that male tropical birds have lower plasma testosterone concentrations than northern latitude species. To test whether this generalization is valid, we analyzed all currently available plasma testosterone data of tropical birds. We focused on peak breeding testosterone levels using phylogenetic and conventional statistics. Explanatory variables considered were social mating system, type of territoriality, breeding season length, and altitude. On average, tropical birds had lower mean peak testosterone levels than northern temperate birds. However, in several tropical species, testosterone levels were well within the range of northern latitude birds. Without controlling for phylogeny, breeding season length, type of territoriality, and altitude explained a significant proportion of the variance in testosterone levels. The shorter the breeding season, the higher the testosterone levels. Tropical birds that defend a breeding season territory had higher testosterone levels than birds that were year-round territorial or colonial, and testosterone levels were positively correlated with altitude. When controlling for phylogeny, only breeding season length predicted testosterone levels. In conclusion, we propose to refine previous notions of low plasma testosterone levels in tropical birds: short breeding seasons and perhaps environmental conditions at high altitudes precipitate conditions under which high testosterone levels are beneficial in the tropics.

  19. Threatened bird valuation in Australia.

    Science.gov (United States)

    Zander, Kerstin K; Ainsworth, Gillian B; Meyerhoff, Jürgen; Garnett, Stephen T

    2014-01-01

    Threatened species programs need a social license to justify public funding. A contingent valuation survey of a broadly representative sample of the Australian public found that almost two thirds (63%) supported funding of threatened bird conservation. These included 45% of a sample of 645 respondents willing to pay into a fund for threatened bird conservation, 3% who already supported bird conservation in another form, and 15% who could not afford to pay into a conservation fund but who nevertheless thought that humans have a moral obligation to protect threatened birds. Only 6% explicitly opposed such payments. Respondents were willing to pay about AUD 11 annually into a conservation fund (median value), including those who would pay nothing. Highest values were offered by young or middle aged men, and those with knowledge of birds and those with an emotional response to encountering an endangered bird. However, the prospect of a bird going extinct alarmed almost everybody, even most of those inclined to put the interests of people ahead of birds and those who resent the way threatened species sometimes hold up development. The results suggest that funding for threatened birds has widespread popular support among the Australian population. Conservatively they would be willing to pay about AUD 14 million per year, and realistically about AUD 70 million, which is substantially more than the AUD 10 million currently thought to be required to prevent Australian bird extinctions.

  20. Evolution of resistance and tolerance to herbivores: testing the trade-off hypothesis

    Directory of Open Access Journals (Sweden)

    Eunice Kariñho-Betancourt

    2015-03-01

    Full Text Available Background. To cope with their natural enemies, plants rely on resistance and tolerance as defensive strategies. Evolution of these strategies among natural population can be constrained by the absence of genetic variation or because of the antagonistic genetic correlation (trade-off between them. Also, since plant defenses are integrated by several traits, it has been suggested that trade-offs might occur between specific defense traits. Methodology/Principal Findings. We experimentally assessed (1 the presence of genetic variance in tolerance, total resistance, and leaf trichome density as specific defense trait, (2 the extent of natural selection acting on plant defenses, and (3 the relationship between total resistance and leaf trichome density with tolerance to herbivory in the annual herb Datura stramonium. Full-sib families of D. stramonium were either exposed to natural herbivores (control or protected from them by a systemic insecticide. We detected genetic variance for leaf trichome density, and directional selection acting on this character. However, we did not detect a negative significant correlation between tolerance and total resistance, or between tolerance and leaf trichome density. We argue that low levels of leaf damage by herbivores precluded the detection of a negative genetic correlation between plant defense strategies. Conclusions/Significance. This study provides empirical evidence of the independent evolution of plant defense strategies, and a defensive role of leaf trichomes. The pattern of selection should favor individuals with high trichomes density. Also, because leaf trichome density reduces damage by herbivores and possess genetic variance in the studied population, its evolution is not constrained.

  1. Testing intermediate-age stellar evolution models with VLT photometry of LMC clusters. I. The data

    CERN Document Server

    Gallart, C; Bertelli, G; Chiosi, C; Demarque, P; Girardi, L; Nasi, E; Woo, J H; Yi, S

    2003-01-01

    This is the first of a series of three papers devoted to the calibration of a few parameters of crucial importance in the modeling of the evolution of intermediate-mass stars, with special attention to the amount of convective core overshoot. To this end we acquired deep V and R photometry for three globular clusters of the Large Magellanic Cloud (LMC), namely NGC 2173, SL 556 and NGC 2155, in the age interval 1-3 Gyr. In this first paper, we describe the aim of the project, the VLT observations and data reduction, and we make preliminary comparisons of the color-magnitude diagrams with both Padova and Yonsei-Yale isochrones. Two following papers in this series present the results of a detailed analysis of these data, independently carried out by members of the Yale and Padova stellar evolution groups. This allows us to compare both sets of models and discuss their main differences, as well as the systematic effects that they would have to the determination of the ages and metallicities of intermediate-age si...

  2. Post-insemination sexual selection in birds.

    Science.gov (United States)

    Pizzari, Tommaso

    2007-01-01

    In many avian species females obtain sperm from multiple males during a single reproductive event, setting the scene for post-insemination sexual selection through the competition of the ejaculates of different males over fertilisation (sperm competition) and female biased utilisation of sperm (cryptic female choice). The use of poultry techniques in combination with molecular tools is catalysing an interest in birds as vertebrate model systems to study the mechanisms of post-insemination sexual selection. This chapter: (i) outlines the main mechanisms of avian sperm competition, (ii) introduces methodological approaches to study post-insemination sexual selection in birds, (iii) reviews recent evidence of multiple mechanisms of strategic sperm allocation by males, and (iv) discusses mechanisms of cryptic female choice. Post-insemination variance in paternity in birds, appears to be determined by the interactions between complex male and female strategies of differential sperm utilisation. It is argued that a better understanding of the operation of post-insemination sexual selection in birds may be achieved through a two-pronged approach which, on the one hand, investigates behavioural and physiological mechanisms applying poultry techniques and molecular tools to domestic model species, and on the other, verifies these mechanisms and tests their adaptive significance in more natural populations.

  3. Performance evolution of 60 kA HTS cable prototypes in the EDIPO test facility

    Science.gov (United States)

    Bykovsky, N.; Uglietti, D.; Sedlak, K.; Stepanov, B.; Wesche, R.; Bruzzone, P.

    2016-08-01

    During the first test campaign of the 60 kA HTS cable prototypes in the EDIPO test facility, the feasibility of a novel HTS fusion cable concept proposed at the EPFL Swiss Plasma Center (SPC) was successfully demonstrated. While the measured DC performance of the prototypes at magnetic fields from 8 T to 12 T and for currents from 30 kA to 70 kA was close to the expected one, an initial electromagnetic cycling test (1000 cycles) revealed progressive degradation of the performance in both the SuperPower and SuperOx conductors. Aiming to understand the reasons for the degradation, additional cycling (1000 cycles) and warm up-cool down tests were performed during the second test campaign. I c performance degradation of the SuperOx conductor reached ∼20% after about 2000 cycles, which was reason to continue with a visual inspection of the conductor and further tests at 77 K. AC tests were carried out at 0 and 2 T background fields without transport current and at 10 T/50 kA operating conditions. Results obtained in DC and AC tests of the second test campaign are presented and compared with appropriate data published recently. Concluding the first iteration of the HTS cable development program at SPC, a summary and recommendations for the next activity within the HTS fusion cable project are also reported.

  4. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

  5. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

  6. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds, and...

  7. Rhode Island, Connecticut, New York, and New Jersey ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, gulls and...

  8. Pretty Bird by Bob Sinclair

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Recently I was reminded of a story which my mother swears is trus (though she doesn t call me Bobby muchanymore):Back in 1958,when I was just past four years old,my parents gave me a young parakeet.My mother determinedthat our parakeet would learn to talk,and to this end sat at the microphone of a borrowed tape recorder for a full 1/2hour,saying over and over again:“Pretty bird!Pretty bird!Pretty bird!Pretty bird!...”and so on.The resultingtaped message was played for our parakeet at least once pe...

  9. Fish and Bird

    Institute of Scientific and Technical Information of China (English)

    毛秀波

    2010-01-01

    人物:B——Bird L——Little Fish M——Mother Fish N——Narracor(旁白)道具:角色头饰 N:一条生活在河里的Little Fish对天空充满了好奇,一心想飞到天空去看看。此时,Little Fish正依偎在Mother Fish身边,好奇地望着天空。

  10. Damage evolution in GLARE fibre-metal laminate under repeated low-velocity impact tests

    Science.gov (United States)

    Morinière, Freddy; Alderliesten, René; Tooski, Mehdi; Benedictus, Rinze

    2012-12-01

    An experimental study was performed on the repeated low-velocity impact behaviour of GLARE. Damage evolution in the material constituents was characterised with successive number of impacts. Records were correlated with visual inspection, ultrasound C-scan and chemical etching. The stiffness of the plate varied when cumulating the number of impacts. Damage accumulation was limited thanks to the synthesis of unidirectional composite and metal. The glass/epoxy plies with high elastic tensile strength could withstand several impacts before perforation despite delamination growth in the vicinity of the impacted area. The damage tolerant aluminium layers prevented the penetration of the projectile and avoided the expansion of delamination. This efficient mechanism preserved the structural integrity of GLARE until first aluminium cracking at the non-impacted side. Among the different failure modes, plate deformation absorbed most of the impact energy. The findings will support the development of a generic quasi-static analytical model and numerical methods.

  11. The Role of Genetic Drift in Shaping Modern Human Cranial Evolution: A Test Using Microevolutionary Modeling

    Directory of Open Access Journals (Sweden)

    Heather F. Smith

    2011-01-01

    Full Text Available The means by which various microevolutionary processes have acted in the past to produce patterns of cranial variation that characterize modern humans is not thoroughly understood. Applying a microevolutionary framework, within- and among-population variance/covariance (V/CV structure was compared for several functional and developmental modules of the skull across a worldwide sample of modern humans. V/CV patterns in the basicranium, temporal bone, and face are proportional within and among groups, which is consistent with a hypothesis of neutral evolution; however, mandibular morphology deviated from this pattern. Degree of intergroup similarity in facial, temporal bone, and mandibular morphology is significantly correlated with geographic distance; however, much of the variance remains unexplained. These findings provide insight into the evolutionary history of modern human cranial variation by identifying signatures of genetic drift, gene flow, and migration and set the stage for inferences regarding selective pressures that early humans encountered since their initial migrations around the world.

  12. Evolution of CMB spectral distortion anisotropies and tests of primordial non-Gaussianity

    CERN Document Server

    Chluba, Jens; Amin, Mustafa A; Kamionkowski, Marc

    2016-01-01

    Anisotropies in distortions to the frequency spectrum of the cosmic microwave background (CMB) can be created through spatially varying heating processes in the early Universe. For instance, the dissipation of small-scale acoustic modes does create distortion anisotropies, in particular for non-Gaussian primordial perturbations. In this work, we derive approximations that allow describing the associated distortion field. We provide a systematic formulation of the problem using Fourier-space window functions, clarifying and generalizing previous approximations. Our expressions highlight the fact that the amplitudes of the spectral-distortion fluctuations induced by non-Gaussianity depend also on the homogeneous value of those distortions. Absolute measurements are thus required to obtain model-independent distortion constraints on primordial non-Gaussianity. We also include a simple description for the evolution of distortions through photon diffusion, showing that these corrections can usually be neglected. O...

  13. Testing the Accuracy of Data-driven MHD Simulations of Active Region Evolution

    Science.gov (United States)

    Leake, James E.; Linton, Mark G.; Schuck, Peter W.

    2017-04-01

    Models for the evolution of the solar coronal magnetic field are vital for understanding solar activity, yet the best measurements of the magnetic field lie at the photosphere, necessitating the development of coronal models which are “data-driven” at the photosphere. We present an investigation to determine the feasibility and accuracy of such methods. Our validation framework uses a simulation of active region (AR) formation, modeling the emergence of magnetic flux from the convection zone to the corona, as a ground-truth data set, to supply both the photospheric information and to perform the validation of the data-driven method. We focus our investigation on how the accuracy of the data-driven model depends on the temporal frequency of the driving data. The Helioseismic and Magnetic Imager on NASA’s Solar Dynamics Observatory produces full-disk vector magnetic field measurements at a 12-minute cadence. Using our framework we show that ARs that emerge over 25 hr can be modeled by the data-driving method with only ∼1% error in the free magnetic energy, assuming the photospheric information is specified every 12 minutes. However, for rapidly evolving features, under-sampling of the dynamics at this cadence leads to a strobe effect, generating large electric currents and incorrect coronal morphology and energies. We derive a sampling condition for the driving cadence based on the evolution of these small-scale features, and show that higher-cadence driving can lead to acceptable errors. Future work will investigate the source of errors associated with deriving plasma variables from the photospheric magnetograms as well as other sources of errors, such as reduced resolution, instrument bias, and noise.

  14. Hybridizing grey wolf optimization with differential evolution for global optimization and test scheduling for 3D stacked SoC

    Institute of Scientific and Technical Information of China (English)

    Aijun Zhu; Chuanpei Xu; Zhi Li; Jun Wu; Zhenbing Liu

    2015-01-01

    A new meta-heuristic method is proposed to enhance current meta-heuristic methods for global optimization and test scheduling for three-dimensional (3D) stacked system-on-chip (SoC) by hybridizing grey wolf optimization with differential evo-lution (HGWO). Because basic grey wolf optimization (GWO) is easy to fal into stagnation when it carries out the operation of at-tacking prey, and differential evolution (DE) is integrated into GWO to update the previous best position of grey wolf Alpha, Beta and Delta, in order to force GWO to jump out of the stagnation with DE’s strong searching ability. The proposed algorithm can accele-rate the convergence speed of GWO and improve its performance. Twenty-three wel-known benchmark functions and an NP hard problem of test scheduling for 3D SoC are employed to verify the performance of the proposed algorithm. Experimental results show the superior performance of the proposed algorithm for exploiting the optimum and it has advantages in terms of exploration.

  15. Phylemon 2.0: a suite of web-tools for molecular evolution, phylogenetics, phylogenomics and hypotheses testing.

    Science.gov (United States)

    Sánchez, Rubén; Serra, François; Tárraga, Joaquín; Medina, Ignacio; Carbonell, José; Pulido, Luis; de María, Alejandro; Capella-Gutíerrez, Salvador; Huerta-Cepas, Jaime; Gabaldón, Toni; Dopazo, Joaquín; Dopazo, Hernán

    2011-07-01

    Phylemon 2.0 is a new release of the suite of web tools for molecular evolution, phylogenetics, phylogenomics and hypotheses testing. It has been designed as a response to the increasing demand of molecular sequence analyses for experts and non-expert users. Phylemon 2.0 has several unique features that differentiates it from other similar web resources: (i) it offers an integrated environment that enables evolutionary analyses, format conversion, file storage and edition of results; (ii) it suggests further analyses, thereby guiding the users through the web server; and (iii) it allows users to design and save phylogenetic pipelines to be used over multiple genes (phylogenomics). Altogether, Phylemon 2.0 integrates a suite of 30 tools covering sequence alignment reconstruction and trimming; tree reconstruction, visualization and manipulation; and evolutionary hypotheses testing.

  16. BIRD FLU MASKS

    Directory of Open Access Journals (Sweden)

    YASAR KESKIN

    2006-08-01

    Full Text Available Avian influenza (bird flu is a disease of birds caused by influenza viruses closely related to human influenza viruses. The potential for transformation of avian influenza into a form that both causes severe disease in humans and spreads easily from person to person is a great concern for world health. The main purpose of a mask is to help prevent particles (droplets being expelled into the environment by the wearer. Masks are also resistant to fluids, and help protect the wearer from splashes of blood or other potentially infectious substances. They are not necessarily designed for filtration efficiency, or to seal tightly to the face. Masks and respirators are components of a number of infection control measures intended to protect healthcare workers, and prevent the spread of diseases. All healthcare workers who come into contact with a possible or probable case of any respiratory track infections should wear a respirator conforming to at least EN149:2001 FFP3. [TAF Prev Med Bull 2006; 5(4.000: 296-306

  17. The evolution of juvenile animal testing for small and large molecules.

    Science.gov (United States)

    Baldrick, Paul

    2013-11-01

    Recent formalised regulatory requirements for ensuring safe use of new drugs in children has increased the requirement, when considered relevant, to perform juvenile animal testing before commencing paediatric clinical trials. A key goal of this work is to identify or examine for a developmental or toxicity finding not seen in other toxicology testing. With our current knowledge, this paper examines what types of testing are occurring, what novel findings are being seen and their relevance in the safety evaluation process. Furthermore, trends for now and the future in the type of juvenile animal testing will be described including a need for more focused study designs and more published data on modern cross-species postnatal development.

  18. Tuberculosis in wild birds: implications for captive birds

    Science.gov (United States)

    Converse, K. A.; Dein, F. J.

    1990-01-01

    The geographic distribution of avian tuberculosis is widespread but the lack of visible epizootics makes assessment of its impact on wild birds difficult. Generally a low prevalence, widely-scattered, individual animal disease, avian tuberculosis is caused by the same agent in wild and domestic birds. Thus there exists the potential for disease transfer between these two groups in situations that result in direct contact such as wild animals newly captured or transferred from rehabilitation centers, and wild and captive animals intermingling in exhibit areas. During the past 7 yr, tuberculosis caused by Mycobacterium avium, was diagnosed in 64 birds submitted to the National Wildlife Health Research Center from 16 states; avian tuberculosis was the primary diagnosis in 52 of the 64 birds, while the remaining 12 isolates were incidental findings. Twenty-eight of these birds were picked up during epizootics caused by other disease agents including avian cholera, botulism type C, and lead, organophosphorus compound, and cyanide poisoning. Twelve birds were found incidental to birds collected during disease monitoring programs and research projects, and 10 birds were collected by hunters or found sick and euthanatized. Tuberculosis lesions occurred (in order of decreasing frequency) in the liver, intestine, spleen, lung, and air sacs. Several unusual morphological presentations were observed in the gizzard, shoulder joint, jugular vein, face, nares and bill, ureter and bone marrow. Infected birds were collected during all 12 mo of the yr from a variety of species in the Anseriformes, Podicipediformes, Gruiformes, and Falconiformes. Nine of the 46 known age birds were immature indicating that lesions can develop during the first year.

  19. Cognitive skills and bacterial load: comparative evidence of costs of cognitive proficiency in birds

    Science.gov (United States)

    Soler, Juan José; Peralta-Sánchez, Juan Manuel; Martín-Vivaldi, Manuel; Martín-Platero, Antonio Manuel; Flensted-Jensen, Einar; Møller, Anders Pape

    2012-02-01

    Parasite-mediated selection may affect the evolution of cognitive abilities because parasites may influence development of the brain, but also learning capacity. Here, we tested some predictions of this hypothesis by analyzing the relationship between complex behaviours (feeding innovations (as a measure of behavioural flexibility) and ability to detect foreign eggs in their nests (i.e. a measure of discriminatory ability)) and abundance of microorganisms in different species of birds. A positive relationship would be predicted if these cognitive abilities implied a larger number of visited environments, while if these skills favoured detection and avoidance of risky environments, a negative relationship would be the prediction. Bacterial loads of eggshells, estimated for mesophilic and potentially pathogenic bacteria (i.e. Enterococcus, Staphylococcus and Enterobacteriaceae), were used as a surrogate of probability of contact with pathogenic bacteria. We found that bird species with higher feeding innovation rates and rejection rates of experimental brood parasitic eggs had higher density of bacteria on their eggshells than the average species. Since the analysed groups of microorganisms include pathogenic bacteria, these results suggest that both feeding innovation and ability to recognize foreign eggs are costly and highlight the importance of parasite-mediated selection in explaining the evolution of cognitive abilities in animals.

  20. FAQ: West Nile Virus and Dead Birds

    Science.gov (United States)

    ... Education Public Service Videos West Nile Virus & Dead Birds Recommend on Facebook Tweet Share Compartir On This ... dead bird sightings to local authorities. How do birds get infected with West Nile virus? West Nile ...

  1. Migration Helps Spread Bird Flu Worldwide

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161473.html Migration Helps Spread Bird Flu Worldwide Scientists recommend keeping ... birds can spread bird flu worldwide and monitoring migration routes could provide early warning of outbreaks, researchers ...

  2. Empirical Tests of Pre-Main-Sequence Stellar Evolution Models with Eclipsing Binaries

    CERN Document Server

    Stassun, Keivan G; Torres, Guillermo

    2014-01-01

    We examine the performance of standard PMS stellar evolution models against the accurately measured properties of a benchmark sample of 26 PMS stars in 13 EB systems. We provide a definitive compilation of all fundamental properties for the EBs. We also provide a definitive compilation of the various PMS model sets. In the H-R diagram, the masses inferred for the individual stars by the models are accurate to better than 10% above 1 Msun, but below 1 Msun they are discrepant by 50-100%. We find evidence that the failure of the models to match the data is linked to the triples in the EB sample; at least half of the EBs possess tertiary companions. Excluding the triples, the models reproduce the stellar masses to better than ~10% in the H-R diagram, down to 0.5 Msun, below which the current sample is fully contaminated by tertiaries. We consider several mechanisms by which a tertiary might cause changes in the EB properties and thus corrupt the agreement with stellar model predictions. We show that the energies...

  3. Serologic evidence of West Nile Virus infection in birds, Tamaulipas State, México.

    Science.gov (United States)

    Fernández-Salas, Ildefonso; Contreras-Cordero, Juan F; Blitvich, Bradley J; González-Rojas, José I; Cavazos-Alvarez, Amanda; Marlenee, Nicole L; Elizondo-Quiroga, Armando; Loroño-Pino, María A; Gubler, Duane J; Cropp, Bruce C; Calisher, Charles H; Beaty, Barry J

    2003-01-01

    Following the introduction of West Nile virus (WNV) into North America in 1999, surveillance for WNV in migratory and resident birds was established in Tamaulipas State, northern México in December 2001. Overall, 796 birds representing 70 species and 10 orders were captured and assayed for antibodies to WNV. Nine birds had flavivirus-specific antibodies by epitope-blocking enzyme-linked immunosorbent assay; four were confirmed to have antibody to WNV by plaque reduction neutralization test. The WNV-infected birds were a house wren, mourning dove, verdin and Bewick's wren. The house wren is a migratory species; the other WNV-infected birds are presumably residents. The WNV-infected birds were all captured in March 2003. These data provide the first indirect evidence of WNV transmission among birds in northern México.

  4. Testing the hypothesis on cognitive evolution of modern humans' learning ability: current status of past-climatic approaches.

    Science.gov (United States)

    Yoneda, Minoru; Abe-Ouchi, Ayako; Kawahata, Hodaka; Yokoyama, Yusuke; Oguchi, Takashi

    2014-05-01

    The impact of climate change on human evolution is important and debating topic for many years. Since 2010, we have involved in a general joint project entitled "Replacement of Neanderthal by Modern Humans: Testing Evolutional Models of Learning", which based on a theoretical prediction that the cognitive ability related to individual and social learning divide fates of ancient humans in very unstable Late Pleistocene climate. This model predicts that the human populations which experienced a series of environmental changes would have higher rate of individual learners, while detailed reconstructions of global climate change have reported fluent and drastic change based on ice cores and stalagmites. However, we want to understand the difference between anatomically modern human which survived and the other archaic extinct humans including European Neanderthals and Asian Denisovans. For this purpose the global synchronized change is not useful for understanding but the regional difference in the amplitude and impact of climate change is the information required. Hence, we invited a geophysicist busing Global Circulation Model to reconstruct the climatic distribution and temporal change in a continental scale. At the same time, some geochemists and geographers construct a database of local climate changes recorded in different proxies. At last, archaeologists and anthropologists tried to interpret the emergence and disappearance of human species in Europe and Asia on the reconstructed past climate maps using some tools, such as Eco-cultural niche model. Our project will show the regional difference in climate change and related archaeological events and its impact on the evolution of learning ability of modern humans.

  5. Epigenetics and sex-specific fitness: an experimental test using male-limited evolution in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Jessica K Abbott

    Full Text Available When males and females have different fitness optima for the same trait but share loci, intralocus sexual conflict is likely to occur. Epigenetic mechanisms such as genomic imprinting (in which expression is altered according to parent-of-origin and sex-specific maternal effects have been suggested as ways by which this conflict can be resolved. However these ideas have not yet been empirically tested. We designed an experimental evolution protocol in Drosophila melanogaster that enabled us to look for epigenetic effects on the X-chromosome-a hotspot for sexually antagonistic loci. We used special compound-X females to enforce father-to-son transmission of the X-chromosome for many generations, and compared fitness and gene expression levels between Control males, males with a Control X-chromosome that had undergone one generation of father-son transmission, and males with an X-chromosome that had undergone many generations of father-son transmission. Fitness differences were dramatic, with experimentally-evolved males approximately 20% greater than controls, and with males inheriting a non-evolved X from their father about 20% lower than controls. These data are consistent with both strong intralocus sexual conflict and misimprinting of the X-chromosome under paternal inheritance. However, expression differences suggested that reduced fitness under paternal X inheritance was largely due to deleterious maternal effects. Our data confirm the sexually-antagonistic nature of Drosophila's X-chromosome and suggest that the response to male-limited X-chromosome evolution entails compensatory evolution for maternal effects, and perhaps modification of other epigenetic effects via coevolution of the sex chromosomes.

  6. Testing cost-benefit models of parental care evolution using lizard populations differing in the expression of maternal care.

    Directory of Open Access Journals (Sweden)

    Wen-San Huang

    Full Text Available Parents are expected to evolve tactics to care for eggs or offspring when providing such care increases fitness above the costs incurred by this behavior. Costs to the parent include the energetic demands of protecting offspring, delaying future fecundity, and increased risk of predation. We used cost-benefit models to test the ecological conditions favoring the evolution of parental care, using lizard populations that differ in whether or not they express maternal care. We found that predators play an important role in the evolution of maternal care because: (1 evolving maternal care is unlikely when care increases predation pressure on the parents; (2 maternal care cannot evolve under low levels of predation pressure on both parents and offspring; and (3 maternal care evolves only when parents are able to successfully defend offspring from predators without increasing predation risk to themselves. Our studies of one of the only known vertebrate species to exhibit interpopulation differences in the expression of maternal care provide clear support for some of the hypothesized circumstances under which maternal care should evolve (e.g., when nests are in exposed locations, parents are able to defend the eggs from predators, and egg incubation periods are brief, but do not support others (e.g., when nest-sites are scarce, life history strategies are "risky", reproductive frequency is low, and environmental conditions are harsh. We conclude that multiple pathways can lead to the evolution of parental care from a non-caring state, even in a single population of a widespread species.

  7. Studying Co-evolution of Production and Test Code Using Association Rule Mining

    NARCIS (Netherlands)

    Lubsen, Z.; Zaidman, A.; Pinzger, M.

    2009-01-01

    Long version of the short paper accepted for publication in the proceedings of the 6th International Working Conference on Mining Software Repositories (MSR 2009). Unit tests are generally acknowledged as an important aid to produce high quality code, as they provide quick feedback to developers on

  8. Damage evolution in different types of concrete by means of splitting tests

    NARCIS (Netherlands)

    Vervuurt, A.; Van Mier, J.G.M.; Chiaia, B.

    1995-01-01

    A new splitting test has been used for evaluating damage in different types of concrete. The set up was developed at the Stevin Laboratory of Delft University of Technology and comprises a completely new loading device in which a perfectly horizontal splitting load can be applied to concrete specim

  9. Existence and uniqueness of dynamic evolutions for a peeling test in dimension one

    Science.gov (United States)

    Dal Maso, Gianni; Lazzaroni, Giuliano; Nardini, Lorenzo

    2016-11-01

    In this paper we present a one-dimensional model of a dynamic peeling test for a thin film, where the wave equation is coupled with a Griffith criterion for the propagation of the debonding front. Our main results provide existence and uniqueness for the solution to this coupled problem under different assumptions on the data.

  10. Assessing readiness for medical education: evolution of the medical college admission test.

    Science.gov (United States)

    McGaghie, William C

    2002-09-01

    The attrition rate of 5% to 50% from US medical schools in the 1920s propelled the development of a test that would measure aptitude for medical studies. Since its development in 1928, the Medical College Admission Test (MCAT) has undergone 5 revisions. The first version was divided into 6 to 8 subtests that focused on memory, knowledge of scientific terminology, reading and comprehension, and logic. The second, which appeared in 1946, was reduced to 4 categories: verbal and quantitative skills, science knowledge, and added a category called understanding modern society. The major difference in the third version, launched in 1962, expanded the test's understanding modern society section to a broader test of general information. In 1977, the MCAT underwent its fourth change: its science section, reading and quantitative skill assessment sections were expanded; its general liberal arts knowledge section was eliminated; its scoring report structure and scoring range were altered; and its cultural and social bias was minimized. The current version, beginning in 1991, has undergone another significant change. Although it does not contain independent measures of either liberal arts or numeracy as separate categories, quantitative skills are needed to solve some of the problems in biological and physical sciences. However, its principal innovation is the writing sample section. Through its 74-year history, the various renditions of the MCAT demonstrate that the definition of aptitude for medical education reflects the professional and social mores and values of the time.

  11. Distinct carbon sources indicate strong differentiation between tropical forest and farmland bird communities.

    Science.gov (United States)

    Ferger, Stefan W; Böhning-Gaese, Katrin; Wilcke, Wolfgang; Oelmann, Yvonne; Schleuning, Matthias

    2013-02-01

    The conversion of forest into farmland has resulted in mosaic landscapes in many parts of the tropics. From a conservation perspective, it is important to know whether tropical farmlands can buffer species loss caused by deforestation and how different functional groups of birds respond to land-use intensification. To test the degree of differentiation between farmland and forest bird communities across feeding guilds, we analyzed stable C and N isotopes in blood and claws of 101 bird species comprising four feeding guilds along a tropical forest-farmland gradient in Kenya. We additionally assessed the importance of farmland insectivores for pest control in C(4) crops by using allometric relationships, C stable isotope ratios and estimates of bird species abundance. Species composition differed strongly between forest and farmland bird communities. Across seasons, forest birds primarily relied on C(3) carbon sources, whereas many farmland birds also assimilated C(4) carbon. While C sources of frugivores and omnivores did not differ between forest and farmland communities, insectivores used more C(4) carbon in the farmland than in the forest. Granivores assimilated more C(4) carbon than all other guilds in the farmland. We estimated that insectivorous farmland birds consumed at least 1,000 kg pest invertebrates km(-2) year(-1). We conclude that tropical forest and farmland understory bird communities are strongly separated and that tropical farmlands cannot compensate forest loss for insectivorous forest understory birds. In tropical farmlands, insectivorous bird species provide a quantitatively important contribution to pest control.

  12. Environmental Determinants Influencing Seasonal Variations of Bird Diversity and Abundance in Wetlands, Northern Region (Ghana

    Directory of Open Access Journals (Sweden)

    Collins Ayine Nsor

    2014-01-01

    Full Text Available The study assessed major environmental determinants influencing bird community in six wetlands over a 2-year period. A combination of visual and bird sounding techniques was used to determine the seasonal variations in bird abundance, while ordination techniques were performed to determine the influence of environmental factors on bird assemblage. A total of 1,169 birds from 25 species and 885 individuals from 23 species were identified in the wet and dry season, respectively. The shallow close marshes supported the greatest number of birds (P<0.05 compared to the riparian wetlands. Bird diversity was significantly higher in the wet season than in the dry season (F=4.101,P<0.05. Cattle egret (Bubulcus ibis and marsh warbler (Acrocephalus palustris were the most abundant. Using the IUCN “Red List” database guide, we noted that 96.2% of birds identified were least concern (LC. The yellow weaver bird (Ploceous megarhrynchus was the only vulnerable species (VU and represented 3.8%. From the three variables tested, bushfire and farming practices were the major threats and cumulatively explained 15.93% (wet season and 14.06% (dry season variations in bird diversity and abundance. These findings will help wetland managers design conservation measures to check current threats on birds from becoming vulnerable in the future.

  13. Webcams for bird detection and monitoring: a demonstration study.

    Science.gov (United States)

    Verstraeten, Willem W; Vermeulen, Bart; Stuckens, Jan; Lhermitte, Stefaan; Van der Zande, Dimitry; Van Ranst, Marc; Coppin, Pol

    2010-01-01

    Better insights into bird migration can be a tool for assessing the spread of avian borne infections or ecological/climatologic issues reflected in deviating migration patterns. This paper evaluates whether low budget permanent cameras such as webcams can offer a valuable contribution to the reporting of migratory birds. An experimental design was set up to study the detection capability using objects of different size, color and velocity. The results of the experiment revealed the minimum size, maximum velocity and contrast of the objects required for detection by a standard webcam. Furthermore, a modular processing scheme was proposed to track and follow migratory birds in webcam recordings. Techniques such as motion detection by background subtraction, stereo vision and lens distortion were combined to form the foundation of the bird tracking algorithm. Additional research to integrate webcam networks, however, is needed and future research should enforce the potential of the processing scheme by exploring and testing alternatives of each individual module or processing step.

  14. Effects of landscape corridors on seed dispersal by birds.

    Energy Technology Data Exchange (ETDEWEB)

    Levey, Douglas, J.; Bolker, Benjamin M.; Tewksbury, Joshua J.; Sargent, Sarah; Haddad, Nick M.

    2005-07-01

    Levey, Douglas, J., Benjamin M. Bolker, Joshua J. Tewksbury, Sarah Sargent, and Nick M. Haddad. 2005. Effects of landscape corridors on seed dispersal by birds. Science 309:146-148. Abstract: Habitat fragmentation threatens biodiversity by disrupting dispersal. The mechanisms and consequences of this disruption are controversial, primarily because most organisms are difficult to track. We examined the effect of habitat corridors on long-distance dispersal of seeds by birds, and tested whether small-scale (G20 meters) movements of birds could be scaled up to predict dispersal of seeds across hundreds of meters in eight experimentally fragmented landscapes. A simulation model accurately predicted the observed pattern of seed rain and revealed that corridors functioned through edge following behavior of birds. Our study shows how models based on easily observed behaviors can be scaled up to predict landscape-level processes.

  15. Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling

    NARCIS (Netherlands)

    Wilts, Bodo D; Michielsen, Kristel; De Raedt, Hans; Stavenga, Doekele G

    2014-01-01

    Birds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced

  16. Was dinosaurian physiology inherited by birds? Reconciling slow growth in archaeopteryx.

    Directory of Open Access Journals (Sweden)

    Gregory M Erickson

    Full Text Available BACKGROUND: Archaeopteryx is the oldest and most primitive known bird (Avialae. It is believed that the growth and energetic physiology of basalmost birds such as Archaeopteryx were inherited in their entirety from non-avialan dinosaurs. This hypothesis predicts that the long bones in these birds formed using rapidly growing, well-vascularized woven tissue typical of non-avialan dinosaurs. METHODOLOGY/PRINCIPAL FINDINGS: We report that Archaeopteryx long bones are composed of nearly avascular parallel-fibered bone. This is among the slowest growing osseous tissues and is common in ectothermic reptiles. These findings dispute the hypothesis that non-avialan dinosaur growth and physiology were inherited in totality by the first birds. Examining these findings in a phylogenetic context required intensive sampling of outgroup dinosaurs and basalmost birds. Our results demonstrate the presence of a scale-dependent maniraptoran histological continuum that Archaeopteryx and other basalmost birds follow. Growth analysis for Archaeopteryx suggests that these animals showed exponential growth rates like non-avialan dinosaurs, three times slower than living precocial birds, but still within the lowermost range for all endothermic vertebrates. CONCLUSIONS/SIGNIFICANCE: The unexpected histology of Archaeopteryx and other basalmost birds is actually consistent with retention of the phylogenetically earlier paravian dinosaur condition when size is considered. The first birds were simply feathered dinosaurs with respect to growth and energetic physiology. The evolution of the novel pattern in modern forms occurred later in the group's history.

  17. Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary.

    Science.gov (United States)

    Longrich, Nicholas R; Tokaryk, Tim; Field, Daniel J

    2011-09-13

    The effect of the Cretaceous-Paleogene (K-Pg) (formerly Cretaceous-Tertiary, K-T) mass extinction on avian evolution is debated, primarily because of the poor fossil record of Late Cretaceous birds. In particular, it remains unclear whether archaic birds became extinct gradually over the course of the Cretaceous or whether they remained diverse up to the end of the Cretaceous and perished in the K-Pg mass extinction. Here, we describe a diverse avifauna from the latest Maastrichtian of western North America, which provides definitive evidence for the persistence of a range of archaic birds to within 300,000 y of the K-Pg boundary. A total of 17 species are identified, including 7 species of archaic bird, representing Enantiornithes, Ichthyornithes, Hesperornithes, and an Apsaravis-like bird. None of these groups are known to survive into the Paleogene, and their persistence into the latest Maastrichtian therefore provides strong evidence for a mass extinction of archaic birds coinciding with the Chicxulub asteroid impact. Most of the birds described here represent advanced ornithurines, showing that a major radiation of Ornithurae preceded the end of the Cretaceous, but none can be definitively referred to the Neornithes. This avifauna is the most diverse known from the Late Cretaceous, and although size disparity is lower than in modern birds, the assemblage includes both smaller forms and some of the largest volant birds known from the Mesozoic, emphasizing the degree to which avian diversification had proceeded by the end of the age of dinosaurs.

  18. Bird on a (live) wire

    Energy Technology Data Exchange (ETDEWEB)

    Farr, M.

    2003-09-30

    Bird mortality as a result of contact with power lines is discussed. U. S. statistics are cited, according to which 174 million birds annually die as a result of contact with power lines, specifically when birds touch two phases of current at the same time. Raptors are particularly vulnerable to power-line electrocution due to their habit of perching on the highest vantage point available as they survey the ground for prey. Hydro lines located in agricultural areas, with bodies of water on one side and fields on the other, also obstruct flight of waterfowl as dusk and dawn when visibility is low. Various solutions designed to minimize the danger to birds are discussed. Among these are: changing the configuration of wires and cross arms to make them more visible to birds in flight and less tempting as perches, and adding simple wire markers such as flags, balloons, and coloured luminescent clips that flap and twirl in the wind. There is no evidence of any coordinated effort to deal with this problem in Ontario. However, a report is being prepared for submission to Environment Canada outlining risks to birds associated with the growing number of wind turbine power generators (negligible compared with power lines and communications towers), and offering suggestions on remedial measures. The Fatal Light Awareness Program (FLAP) also plans to lobby the Canadian Wildlife Service to discuss the possibility of coordinating efforts to monitor, educate about and ultimately reduce this form of bird mortality.

  19. Surveillance for Avian Influenza Viruses in Wild Birds in Denmark and Greenland, 2007–10

    DEFF Research Database (Denmark)

    Hjulsager, Charlotte Kristiane; Breum, Solvej Østergaard; Trebbien, Ramona;

    2012-01-01

    In Denmark and Greenland, extensive surveillance of avian influenza (AI) viruses in wild bird populations has been conducted from 2007 through 2010. In Denmark, the surveillance consisted of passive surveillance of wild birds found dead or sick across Denmark and active surveillance of apparently...... were birds that were found dead. In Greenland, samples were collected mainly from fecal droppings in breeding areas. Samples from 3555 live and apparently healthy wild birds were tested. All swab samples were tested by pan-influenza reverse transcriptase–PCR (RT-PCR), and the positive samples were...

  20. Risk of Agricultural Practices and Habitat Change to Farmland Birds

    Directory of Open Access Journals (Sweden)

    David Anthony. Kirk

    2011-06-01

    Full Text Available Many common bird species have declined as a result of agricultural intensification and this could be mitigated by organic farming. We paired sites for habitat and geographical location on organic and nonorganic farms in Ontario, Canada to test a priori predictions of effects on birds overall, 9 guilds and 22 species in relation to candidate models for farming practices (13 variables, local habitat features (12 variables, or habitat features that influence susceptibility to predation. We found that: (1 Overall bird abundance, but not richness, was significantly (p < 0.05 higher on organic sites (mean 43.1 individuals per site than nonorganic sites (35.8 individuals per site. Significantly more species of birds were observed for five guilds, including primary grassland birds, on organic vs. nonorganic sites. No guild had higher richness or abundance on nonorganic farms; (2 Farming practice models were the best (Î"AIC < 4 for abundance of birds overall, primary grassland bird richness, sallier aerial insectivore richness and abundance, and abundance of ground nesters; (3 Habitat models were the best for overall richness, Neotropical migrant abundance, richness and abundance of Ontario-USA-Mexico (short-distance migrants and resident richness; (4 Predation models were the best for richness of secondary grassland birds and ground feeders; (5 A combination of variables from the model types were best for richness or abundance overall, 13 of 18 guilds (richness and abundance and 16 of 22 species analyzed. Five of 10 farming practice variables (including herbicide use, organic farm type and 9 of 13 habitat variables (including hedgerow length, proportion of hay were significant in best models. Risk modeling indicated that herbicide use could decrease primary grassland birds by one species (35% decline from 3.4 to 2.3 species per site. Organic farming could benefit species of conservation concern by 49% (an increase from 7.6 to 11.4 grassland birds. An

  1. Bristol Bay, Alaska Subarea ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for shorebirds, waterfowl, raptors, diving birds, and seabirds in the Bristol Bay Subarea. The Subarea...

  2. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Nyegaard, Timme; Heldbjerg, Henning; Fox, Anthony David

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to bird species in Denmark. A new European Union Regulation on Invasive...... the importance of mechanisms such as DOFs (Danish Ornithological Society, BirdLife Denmark) Atlas project, Common Bird Monitoring (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already present...

  3. Birds of the Mongol Empire

    Directory of Open Access Journals (Sweden)

    Eugene N. Anderson

    2016-09-01

    Full Text Available The Mongol Empire, the largest contiguous empire the world has ever known, had, among other things, a goodly number of falconers, poultry raisers, birdcatchers, cooks, and other experts on various aspects of birding. We have records of this, largely in the Yinshan Zhengyao, the court nutrition manual of the Mongol empire in China (the Yuan Dynasty. It discusses in some detail 22 bird taxa, from swans to chickens. The Huihui Yaofang, a medical encyclopedia, lists ten taxa used medicinally. Marco Polo also made notes on Mongol bird use. There are a few other records. This allows us to draw conclusions about Mongol ornithology, which apparently was sophisticated and detailed.

  4. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

    2015-01-01

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

  5. Solar wind stream evolution at large heliocentric distances - Experimental demonstration and the test of a model

    Science.gov (United States)

    Gosling, J. T.; Hundhausen, A. J.; Bame, S. J.

    1976-01-01

    A stream propagation model which neglects all dissipation effects except those occurring at shock interfaces, was used to compare Pioneer-10 solar wind speed observations, during the time when Pioneer 10, the earth, and the sun were coaligned, with near-earth Imp-7 observations of the solar wind structure, and with the theoretical predictions of the solar wind structure at Pioneer 10 derived from the Imp-7 measurements, using the model. The comparison provides a graphic illustration of the phenomenon of stream steepening in the solar wind with the attendant formation of forward-reverse shock pairs and the gradual decay of stream amplitudes with increasing heliocentric distance. The comparison also provides a qualitative test of the stream propagation model.

  6. Differential effects of magnetic pulses on the orientation of naturally migrating birds.

    Science.gov (United States)

    Holland, Richard A

    2010-11-01

    In migratory passerine birds, strong magnetic pulses are thought to be diagnostic of the remagnetization of iron minerals in a putative sensory system contained in the beak. Previous evidence suggests that while such a magnetic pulse affects the orientation of migratory birds in orientation cages, no effect was present when pulse-treated birds were tested in natural migration. Here we show that two migrating passerine birds treated with a strong magnetic pulse, designed to alter the magnetic sense, migrated in a direction that differed significantly from that of controls when tested in natural conditions. The orientation of treated birds was different depending on the alignment of the pulse with respect to the magnetic field. These results can aid in advancing understanding of how the putative iron-mineral-based receptors found in birds' beaks may be used to detect and signal the intensity and/or direction of the Earth's magnetic field.

  7. Selecting the right bird model in experimental studies on endocrine disrupting chemicals

    Directory of Open Access Journals (Sweden)

    Veerle L.B. Jaspers

    2015-05-01

    Full Text Available Birds have been used as model species in ecotoxicological research for decades but have only recently been included in toxicity testing schemes. However, the avian fauna is very diverse. Given this diversity the ecology, behavior and reproduction should be considered when selecting the appropriate bird model in ecotoxicological studies. This article focusses on choosing the right bird model species for experimental studies with endocrine disrupting chemicals (EDCs. EDCs have been associated with adverse effects on the reproduction and development in birds and other wildlife. In addition, new EDCs continue to emerge and the concern for potential effects in humans and wildlife is calling for increased toxicity testing and hence appropriate model species. Common bird model species used in ecotoxicological studies investigating EDCs will be reviewed. In addition, considerations for selecting the right bird model, along with potential drawbacks and restrictions on the use of certain species will be discussed.

  8. 21 CFR 1240.65 - Psittacine birds.

    Science.gov (United States)

    2010-04-01

    ... DISEASES Specific Administrative Decisions Regarding Interstate Shipments § 1240.65 Psittacine birds. (a) The term psittacine birds shall include all birds commonly known as parrots, Amazons, Mexican double... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Psittacine birds. 1240.65 Section 1240.65 Food...

  9. Does morphological convergence imply functional similarity? A test using the evolution of quadrupedalism in ornithischian dinosaurs.

    Science.gov (United States)

    Maidment, Susannah C R; Barrett, Paul M

    2012-09-22

    Convergent morphologies are thought to indicate functional similarity, arising because of a limited number of evolutionary or developmental pathways. Extant taxa displaying convergent morphologies are used as analogues to assess function in extinct taxa with similar characteristics. However, functional studies of extant taxa have shown that functional similarity can arise from differing morphologies, calling into question the paradigm that form and function are closely related. We test the hypothesis that convergent skeletal morphology indicates functional similarity in the fossil record using ornithischian dinosaurs. The rare transition from bipedality to quadrupedality occurred at least three times independently in this clade, resulting in a suite of convergent osteological characteristics. We use homology rather than analogy to provide an independent line of evidence about function, reconstructing soft tissues using the extant phylogenetic bracket and applying biomechanical concepts to produce qualitative assessments of muscle leverage. We also optimize character changes to investigate the sequence of character acquisition. Different lineages of quadrupedal ornithischian dinosaur stood and walked differently from each other, falsifying the hypothesis that osteological convergence indicates functional similarity. The acquisition of features correlated with quadrupedalism generally occurs in the same order in each clade, suggesting underlying developmental mechanisms that act as evolutionary constraints.

  10. North American Breeding Bird Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This protocol framework provides guidance for conducting surveys of North American bird populations at multiple stations within two or more regions. The BBS is a...

  11. Poisonous birds: A timely review.

    Science.gov (United States)

    Ligabue-Braun, Rodrigo; Carlini, Célia Regina

    2015-06-01

    Until very recently, toxicity was not considered a trait observed in birds, but works published in the last two decades started to shed light on this subject. Poisonous birds are rare (or little studied), and comprise Pitohui and Ifrita birds from Papua New Guinea, the European quail, the Spoor-winged goose, the Hoopees, the North American Ruffed grouse, the Bronzewings, and the Red warbler. A hundred more species are considered unpalatable or malodorous to humans and other animals. The present review intends to present the current understanding of bird toxicity, possibly pointing to an ignored research field. Whenever possible, biochemical characteristics of these poisons and their effects on humans and other animals are discussed, along with historical aspects of poison discovery and evolutionary hypothesis regarding their function.

  12. Barrier Infrared Detector (BIRD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — JPL will design, fabricate, and fully characterize a 640x512 format HOT-BIRD FPA with increased quantum efficiency and extended spectral coverage. Unlike the small...

  13. Application of fractional algorithms in the control of a robotic bird

    Science.gov (United States)

    Couceiro, Micael S.; Fonseca Ferreira, N. M.; Tenreiro Machado, J. A.

    2010-04-01

    In this paper, it is studied the dynamics of the robotic bird in terms of time response and robustness. It is analyzed the wing angle of attack and the velocity of the bird, the tail influence, the gliding flight and the flapping flight. The results are positive for the construction of flying robots. The development of computational simulation based on the dynamic of the robotic bird should allow testing strategies and different algorithms of control such as integer and fractional controllers.

  14. Process compensated resonance testing modeling for damage evolution and uncertainty quantification

    Science.gov (United States)

    Biedermann, Eric; Heffernan, Julieanne; Mayes, Alexander; Gatewood, Garrett; Jauriqui, Leanne; Goodlet, Brent; Pollock, Tresa; Torbet, Chris; Aldrin, John C.; Mazdiyasni, Siamack

    2017-02-01

    Process Compensated Resonance Testing (PCRT) is a nondestructive evaluation (NDE) method based on the fundamentals of Resonant Ultrasound Spectroscopy (RUS). PCRT is used for material characterization, defect detection, process control and life monitoring of critical gas turbine engine and aircraft components. Forward modeling and model inversion for PCRT have the potential to greatly increase the method's material characterization capability while reducing its dependence on compiling a large population of physical resonance measurements. This paper presents progress on forward modeling studies for damage mechanisms and defects in common to structural materials for gas turbine engines. Finite element method (FEM) models of single crystal (SX) Ni-based superalloy Mar-M247 dog bones and Ti-6Al-4V cylindrical bars were created, and FEM modal analyses calculated the resonance frequencies for the samples in their baseline condition. Then the frequency effects of superalloy creep (high-temperature plastic deformation) and macroscopic texture (preferred crystallographic orientation of grains detrimental to fatigue properties) were evaluated. A PCRT sorting module for creep damage in Mar-M247 was trained with a virtual database made entirely of modeled design points. The sorting module demonstrated successful discrimination of design points with as little as 1% creep strain in the gauge section from a population of acceptable design points with a range of material and geometric variation. The resonance frequency effects of macro-scale texture in Ti-6Al-4V were quantified with forward models of cylinder samples. FEM-based model inversion was demonstrated for Mar-M247 bulk material properties and variations in crystallographic orientation. PCRT uncertainty quantification (UQ) was performed using Monte Carlo studies for Mar-M247 that quantified the overall uncertainty in resonance frequencies resulting from coupled variation in geometry, material properties, crystallographic

  15. Pediatric Exposure to Drugs of Abuse by Hair Testing: Monitoring 15 Years of Evolution in Spain

    Directory of Open Access Journals (Sweden)

    Simona Pichini

    2014-08-01

    Full Text Available Hair testing is a useful tool to investigate the prevalence of unsuspected chronic exposure to drugs of abuse in pediatric populations and it has been applied to three different cohorts of children from Barcelona, Spain along fifteen years to evaluate eventual changes in this exposure. Children were recruited from three independent studies performed at Hospital del Mar (Barcelona, Spain and approved by the local Ethics Committee. Hair samples were collected from the first 187 children cohort (around 4 years of age in 1998, from the second 90 children cohort (1.5–5 years of age in 2008 and from the third 114 children cohort (5–14 years of age in 2013. Hair samples were analysed for the presence of opiates, cocaine, amphetamines, and cannabis by validated methodologies using gas or liquid chromatography-mass spectrometry. Familiar sociodemographics and eventual consumption of drugs of abuse by parents, and caregivers were recorded. Hair samples from 24.6% children in 1998 were positive for any drug of abuse (23.0% cocaine, 25.5% in 2008 (23.3% cocaine, and 28.1% in 2013 (20.1% cocaine and 11.4% cannabis. In none of the cohorts, parental sociodemographics were associated with children exposure to drugs of abuse. The results of the three study cohorts demonstrated a significant prevalence of unsuspected pediatric exposure to drugs of abuse which mainly involved cocaine maintained along fifteen years in Barcelona, Spain. We recommend to be aware about unsuspected passive exposure to drugs of abuse in general population and to use general or selected hair screening to disclose exposure to drugs of abuse in children from risky environments to provide the basis for specific social and health interventions.

  16. The Effects of Molecular Properties on Ready Biodegradation of Aromatic Compounds in the OECD 301B CO2 Evolution Test.

    Science.gov (United States)

    He, Mei; Mei, Cheng-Fang; Sun, Guo-Ping; Li, Hai-Bei; Liu, Lei; Xu, Mei-Ying

    2016-07-01

    Ready biodegradation is the primary biodegradability of a compound, which is used for discriminating whether a compound could be rapidly and readily biodegraded in the natural ecosystems in a short period and has been applied extensively in the environmental risk assessment of many chemicals. In this study, the effects of 24 molecular properties (including 2 physicochemical parameters, 10 geometrical parameters, 6 topological parameters, and 6 electronic parameters) on the ready biodegradation of 24 kinds of synthetic aromatic compounds were investigated using the OECD 301B CO2 Evolution test. The relationship between molecular properties and ready biodegradation of these aromatic compounds varied with molecular properties. A significant inverse correlation was found for the topological parameter TD, five geometrical parameters (Rad, CAA, CMA, CSEV, and N c), and the physicochemical parameter K ow, and a positive correlation for two topological parameters TC and TVC, whereas no significant correlation was observed for any of the electronic parameters. Based on the correlations between molecular properties and ready biodegradation of these aromatic compounds, the importance of molecular properties was demonstrated as follows: geometrical properties > topological properties > physicochemical properties > electronic properties. Our study first demonstrated the effects of molecular properties on ready biodegradation by a number of experiment data under the same experimental conditions, which should be taken into account to better guide the ready biodegradation tests and understand the mechanisms of the ready biodegradation of aromatic compounds.

  17. 75 FR 53774 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Science.gov (United States)

    2010-09-01

    ... Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain...-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain..., Interior. ACTION: Final rule. SUMMARY: This rule prescribes special early-season migratory bird...

  18. 77 FR 29515 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2012-05-17

    ... Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2012-13... RIN 1018-AX97 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting... in an earlier document to establish annual hunting regulations for certain migratory game birds...

  19. 77 FR 23093 - Migratory Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary...

    Science.gov (United States)

    2012-04-17

    ... Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian Tribal Proposals and Requests for 2014 Spring and Summer Migratory Bird Subsistence Harvest... Migratory Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary) With...

  20. 76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

    Science.gov (United States)

    2011-06-03

    ... Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by the Armed Forces AGENCY: Fish and... birds during approved military readiness activities without violating the Migratory Bird Treaty Act... the Armed Forces to incidentally take migratory birds. The Authorization Act also stated that...

  1. Unzipping bird feathers

    Science.gov (United States)

    Kovalev, Alexander; Filippov, Alexander E.; Gorb, Stanislav N.

    2014-01-01

    The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments. PMID:24352674

  2. Energetics, lifestyle, and reproduction in birds.

    Science.gov (United States)

    Sibly, Richard M; Witt, Christopher C; Wright, Natalie A; Venditti, Chris; Jetz, Walter; Brown, James H

    2012-07-03

    Theoretical and empirical studies of life history aim to account for resource allocation to the different components of fitness: survival, growth, and reproduction. The pioneering evolutionary ecologist David Lack [(1968) Ecological Adaptations for Breeding in Birds (Methuen and Co., London)] suggested that reproductive output in birds reflects adaptation to environmental factors such as availability of food and risk of predation, but subsequent studies have not always supported Lack's interpretation. Here using a dataset for 980 bird species (Dataset S1), a phylogeny, and an explicit measure of reproductive productivity, we test predictions for how mass-specific productivity varies with body size, phylogeny, and lifestyle traits. We find that productivity varies negatively with body size and energetic demands of parental care and positively with extrinsic mortality. Specifically: (i) altricial species are 50% less productive than precocial species; (ii) species with female-only care of offspring are about 20% less productive than species with other methods of parental care; (iii) nonmigrants are 14% less productive than migrants; (iv) frugivores and nectarivores are about 20% less productive than those eating other foods; and (v) pelagic foragers are 40% less productive than those feeding in other habitats. A strong signal of phylogeny suggests that syndromes of similar life-history traits tend to be conservative within clades but also to have evolved independently in different clades. Our results generally support both Lack's pioneering studies and subsequent research on avian life history.

  3. Trypanosomes of some Fennoscandian birds

    Directory of Open Access Journals (Sweden)

    Gordon F. Bennett

    1994-12-01

    Full Text Available Linear measurements and derived indices of trypanosomes from species of Fennoscandian birds were compared to those reported form Trypanosoma avium, T. everetti, T. ontarioensis and T. paddae. The trypanosomes encountered in the Fennoscandian birds were identified as T. avium from Tengmalm's owl Aegolius funereus and the pied flycatcher Ficedula hypoleuca, T. everetti from the great tit Parus major and collared flycatcher F. albicollis and T. ontarioensis from the collared flycatcher; T. paddae was not seen.

  4. Orientation and navigation in birds

    Directory of Open Access Journals (Sweden)

    H. Bouwman

    1998-07-01

    Full Text Available How birds orientate and navigate over long distances, remains one of the subjects of ornithology eliciting much interest. Birds use combinations of different sources of information to find direction and position. Some of these are the geomagnetic field, celestial bodies, mosaic and gradient maps, sound, smell, idiotetic information and others. Different species use different combinations of sources. This ability is partially inherent and partially learned.

  5. Sleeping birds do not respond to predator odour.

    Directory of Open Access Journals (Sweden)

    Luisa Amo

    Full Text Available BACKGROUND: During sleep animals are relatively unresponsive and unaware of their environment, and therefore, more exposed to predation risk than alert and awake animals. This vulnerability might influence when, where and how animals sleep depending on the risk of predation perceived before going to sleep. Less clear is whether animals remain sensitive to predation cues when already asleep. METHODOLOGY/PRINCIPAL FINDINGS: We experimentally tested whether great tits are able to detect the chemical cues of a common nocturnal predator while sleeping. We predicted that birds exposed to the scent of a mammalian predator (mustelid twice during the night would not go into torpor (which reduces their vigilance and hence would not reduce their body temperature as much as control birds, exposed to the scent of another mammal that does not represent a danger for the birds (rabbit. As a consequence of the higher body temperature birds exposed to the scent of a predator are predicted to have a higher resting metabolic rate (RMR and to lose more body mass. In the experiment, all birds decreased their body temperature during the night, but we did not find any influence of the treatment on body temperature, RMR, or body mass. CONCLUSIONS/SIGNIFICANCE: Our results suggest that birds are not able to detect predator chemical cues while sleeping. As a consequence, antipredatory strategies taken before sleep, such as roosting sites inspection, may be crucial to cope with the vulnerability to predation risk while sleeping.

  6. Effects of food supplementation on a tropical bird.

    Science.gov (United States)

    Class, Alexandra M; Moore, Ignacio T

    2013-10-01

    Tropical birds typically exhibit a 'slow pace of life' relative to higher latitude species. This is often manifested as slow development, low fecundity, and high survival. Following from this, it is predicted that tropical birds may be more likely to trade current reproductive effort to favor self-maintenance, thus supporting survival and future reproduction. To test this idea, we conducted two food supplementation experiments on tropical rufous-collared sparrows (Zonotrichia capensis) in the eastern Andes of Ecuador. In the first experiment, we food-supplemented pairs during the non-breeding life-history stage, and in the second experiment, we food-supplemented pairs that were provisioning fledglings. In both experiments, a larger proportion of food-supplemented birds exhibited pre-basic molt (replacement of feathers) than in a control group. To our knowledge, this is the first study to experimentally demonstrate that a food-supplemented bird invests extra resources into molt, a form of self-maintenance, and contrasts with the majority of food supplementation studies in high latitude birds that show they typically advance the initiation of, or extend the period of, reproduction. Our results are consistent with the syndrome of the slow pace of life in the tropics and support the concept of fundamental differences between temperate-zone and tropical birds.

  7. Linking foraging decisions to residential yard bird composition.

    Directory of Open Access Journals (Sweden)

    Susannah B Lerman

    Full Text Available Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity.

  8. Linking foraging decisions to residential yard bird composition.

    Science.gov (United States)

    Lerman, Susannah B; Warren, Paige S; Gan, Hilary; Shochat, Eyal

    2012-01-01

    Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays) in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs) compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards) contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity.

  9. Bird predation affects diurnal and nocturnal web-building spiders in a Mediterranean citrus grove

    Science.gov (United States)

    Mestre, L.; Garcia, N.; Barrientos, J. A.; Espadaler, X.; Piñol, J.

    2013-02-01

    Spiders and birds can greatly decrease insect populations, but birds also limit spider densities in some habitats. Bird predation is thought to be one of the causes behind nocturnal activity in spiders, so night-active spiders that hide in retreats during the day should be less affected by bird foraging than day-active spiders. However, this hypothesis has not yet been tested. We investigated the importance of bird predation on the spider community of a Mediterranean organic citrus grove. We excluded birds by placing net cages over the trees and we conducted visual searches in the canopies to sample web-building spiders. As there are many nocturnal species in the family Araneidae, we conducted searches both by day and by night to compare the abundance of active araneids in these two time periods. We sampled the tree trunks with cardboard bands to collect hunting spiders. In bird-excluded canopies there were more spiders of the families Araneidae and Theridiidae. There were higher numbers of active Araneidae at night, but these were just as negatively affected by bird predation as day-active Araneidae, so there was no evidence of nocturnal activity serving as an anti-predator strategy. We did not find any negative impact of birds on hunting spiders. Our results contrast with other studies reporting a negative effect of birds on hunting but not on web-building spiders.

  10. Pathologic findings in racing pigeons (Columba livia domestica) with "young bird sickness".

    Science.gov (United States)

    Scullion, Francis T; Scullion, Mary Geraldine

    2007-03-01

    "Young bird sickness" is a term used by racing pigeon fanciers to describe a condition that has occurred regularly in recent years and affects pigeons (Columba livia domestica) in their first year of life. It is characterized by slow crop emptying, regurgitation, diarrhea, weight loss, poor performance, and occasionally death. Little scientific information is known about this syndrome to differentiate it from other diseases that occur in young pigeons. In this study, 1 bird from each of 9 lofts where "young bird sickness" was reported was euthanatized for cytologic and postmortem examination. Lesions of the lymphoreticular system, alimentary tract, and respiratory system were the most common findings. Lesions of the lymphoreticular system were present in all birds examined, and 3 birds had histopathologic findings consistent with circovirus infection. Combinations of protozoal, fungal, and mixed bacterial infections were associated with ingluvitis in 7 birds and enteritis in 6 birds. Pneumonitis was found in 5 birds that tested positive for Chlamydophila by polymerase chain reaction. Although "young bird sickness" appears to be a multifactorial condition, a pattern of lesions that involved the lymphoreticular, gastrointestinal, and respiratory systems was evident, whereas diseases of other organ systems were uncommon. These findings suggest that "young bird sickness" may have a common etiology, and circovirus infection is proposed as a possible initiating cause of this syndrome in young racing pigeons in Northern Ireland.

  11. Composition and structure of bird communities in vegetational gradients of Bodoquena Mountains, western Brazil.

    Science.gov (United States)

    Godoi, Mauricio N; Souza, Franco L; Laps, Rudi R; Ribeiro, Danilo B

    2016-03-01

    The informations of bird species distribution in different habitats and the structure of their communities are crucial for bird conservation. We tested the differences in composition, richness and abundance of birds in different phytophysiognomies at Bodoquena Mountains, western Brazil, and we demonstrated the variations in richness and abundance of birds between different trophic groups. Sampling was conducted between July 2011 and June 2012 in 200 point counts arranged in the study area. A total of 3350 contacts were obtained belonging to 156 bird species. Woodland savannas, seasonal forests and arboreal savannas had higher bird abundance and richness, while riparian forests, clean pastures and dirty pastures had smaller values of these parameters. The bird community was organized according to local vegetational gradient, with communities of forests, open areas and savannas, although many species occurred in more than one vegetation type. The insectivorous, omnivorous, frugivorous and gramnivorous birds composed most of the community. These data showed how important environmental heterogeneity is to bird communities. Furthermore, the presence of extensive patches of natural habitats, the small distance between these patches and the permeability of pastures, with high arboreal and shrubby cover, are indicated as important factors to maintain the bird diversity.

  12. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, passerine birds, and gulls and terns in the...

  13. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northern California: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, passerines, pelagic birds, raptors, shorebirds, wading birds, and...

  14. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northwest Arctic, Alaska: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, and gulls/terns in Northwest...

  15. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Florida Panhandle: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  16. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Mississippi: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  17. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: North Carolina: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  18. Lab-on-a-bird: biophysical monitoring of flying birds.

    Science.gov (United States)

    Gumus, Abdurrahman; Lee, Seoho; Ahsan, Syed S; Karlsson, Kolbeinn; Gabrielson, Richard; Guglielmo, Christopher G; Winkler, David W; Erickson, David

    2015-01-01

    The metabolism of birds is finely tuned to their activities and environments, and thus research on avian systems can play an important role in understanding organismal responses to environmental changes. At present, however, the physiological monitoring of bird metabolism is limited by the inability to take real-time measurements of key metabolites during flight. In this study, we present an implantable biosensor system that can be used for continuous monitoring of uric acid levels of birds during various activities including flight. The system consists of a needle-type enzymatic biosensor for the amperometric detection of uric acid in interstitial fluids. A lightweight two-electrode potentiostat system drives the biosensor, reads the corresponding output current and wirelessly transfers the data or records to flash memory. We show how the device can be used to monitor, in real time, the effects of short-term flight and rest cycles on the uric acid levels of pigeons. In addition, we demonstrate that our device has the ability to measure uric acid level increase in homing pigeons while they fly freely. Successful application of the sensor in migratory birds could open up a new way of studying birds in flight which would lead to a better understanding of the ecology and biology of avian movements.

  19. Blood protozoa of imported birds.

    Science.gov (United States)

    Manwell, R D; Rossi, G S

    1975-02-01

    Large numbers of birds, until recently, were brought into the United States each year. Countries of origin were varied, and included those of Australasia, Africa, South America, and the Caribbean islands, as well as other places. With them of course come their parasites, some of which may be potential pathogens to domestic avifauna. In part for this reason, a survey was undertaken of blood parasites of birds from pet shops and importers. So far a total of 1234 birds belonging to 186 species has been examined. Several new species and subspecies of avian Plasmodium have been found in the course of this study, including P. octamerium Manwell, 1968 in a Pintail Whydah, Vidua macoura, from Africa; P paranucleophilum Manwell & Sessler, 1971 in a South American tanager, Tachyphonus sp; and P. nucleophilum toucani Manwell & Sessler 1971 in a Swainson's Toucan, Ramphastos s. swainsonii. Plasmodium huffi Muniz, Soares & Battista is undoubtedly a synonym pro parte for the last. Plasmodium tenue Laveran & Maruliaz, long thought to be a synonym of Plasmodium vaughani Novy & MacNeal, was rediscovered and found to be a valid species. Plasmodium nucleophilum, infrequently seen in the New World, occurred in many Asian and African birds, and especially in starlings. Infections with other species of Plasmodium were common. Haemoproteus was the commonest blood parasite; Leucocytozoon was very rare as was Atoxoplasma (Lankesterella). The 2 families of birds best represented were the Fringillidae and the Psittacidae, but no blood parasites were seen in the latter. It is clear that imported birds are often infected with blood protozoa, some of which are unknown from native birds.

  20. The ornithologist Alfred Russel Wallace and the controversy surrounding the dinosaurian origin of birds.

    Science.gov (United States)

    Ibrahim, Nizar; Kutschera, Ulrich

    2013-12-01

    Over many years of his life, the British naturalist Alfred Russel Wallace (1823-1913) explored the tropical forests of Malaysia, collecting numerous specimens, including hundreds of birds, many of them new to science. Subsequently, Wallace published a series of papers on systematic ornithology, and discovered a new species on top of a volcano on Ternate, where he wrote, in 1858, his famous essay on natural selection. Based on this hands-on experience, and an analysis of an Archaeopteryx fossil, Wallace suggested that birds may have descended from dinosaurian ancestors. Here, we describe the "dinosaur-bird hypothesis" that originated with the work of Thomas H. Huxley (1825-1895). We present the strong evidence linking theropod dinosaurs to birds, and briefly outline the long and ongoing controversy around this concept. Dinosaurs preserving plumage, nesting sites and trace fossils provide overwhelming evidence for the dinosaurian origin of birds. Based on these recent findings of paleontological research, we conclude that extant birds indeed descended, with some modifications, from small, Mesozoic theropod dinosaurs. In the light of Wallace's view of bird origins, we critically evaluate recent opposing views to this idea, including Ernst Mayr's (1904-2005) arguments against the "dinosaur-bird hypothesis", and document that this famous ornithologist was not correct in his assessment of this important aspect of vertebrate evolution.

  1. Bird fruit preferences match the frequency of fruit colours in tropical Asia.

    Science.gov (United States)

    Duan, Qiong; Goodale, Eben; Quan, Rui-chang

    2014-07-17

    While many factors explain the colour of fleshy fruits, it is thought that black and red fruits are common in part because frugivorous birds prefer these colours. We examined this still controversial hypothesis at a tropical Asian field site, using artificial fruits, fresh fruits, four wild-caught resident frugivorous bird species, and hand-raised naïve birds from three of the same species. We demonstrate that all birds favored red artificial fruits more than yellow, blue, black and green, although the artificial black colour was found subsequently to be similar to the artificial blue colour in its spectral reflectance. Wild-caught birds preferred both black and red fleshy natural fruits, whereas hand-raised naïve birds preferred black to red natural fleshy fruits and to those of other colours. All birds avoided artificial and naturally ripe green fruits. The inter-individual variation in colour choice was low and the preferences were constant over time, supporting the hypothesis that bird colour preferences are a contributing factor driving fruit colour evolution in tropical Asia.

  2. [Stable morphologies and mosaicism in the macroevolution of birds (Neornithes)].

    Science.gov (United States)

    Zelenkov, N V

    2015-01-01

    Modern orders of Neornithine birds are separated by distinct morphological gaps, hampering the development of particular models. of macroevolutionary transformations. However, recent decades have witnessed the discovery and extensive study of many fossil groups of birds, which shed light on the origin of modern higher taxa. These fossils further allow analyzing the whole process of the macroevolutionary change in this group of vertebrates during the Cenozoic. Here, a brief review is presented of the "transitional" taxa with special attention to representative of the clade Galloanseres. Almost all transitional groups of fossil birds do display mosaic morphology. It is noted that many stable morphologies (characters and character complexes) persist in different groups, occurring either as primitive states, or as advanced ones. The stable recurrence of these characters is caused by the persistence of stable ontogenetic pathways. On the other hand, independent evolution of various morphologies can be explained by the modular organization of the development. The modularity in the structure of the foot is used here as an example to show a possible way of the origin of the foot in extant perching birds (Passeriformes). The mosaic morphology of the transitional taxa is seen as the only possible way to overcome the evolutionary constraint of the parallel optimization of numerous organismal systems. It is noted that in course of macroevolutionary change, no complete filling of morphological gaps occur. Transitional forms are separated by additional gaps from their ancestors and descendants. Hence, stem groups are seen as the most probable ancestors of crown taxa. It is further noted that the evolutionary formation of some higher taxa of the living birds was initiated by the evolution of advanced morphology of the feeding apparatus and skull, while change in their. postcranial morphology was delayed.

  3. Elevational distribution and extinction risk in birds.

    Directory of Open Access Journals (Sweden)

    Rachel L White

    Full Text Available Mountainous regions are hotspots of terrestrial biodiversity. Unlike islands, which have been the focus of extensive research on extinction dynamics, fewer studies have examined mountain ranges even though they face increasing threats from human pressures - notably habitat conversion and climate change. Limits to the taxonomic and geographical extent and resolution of previously available information have precluded an explicit assessment of the relative role of elevational distribution in determining extinction risk. We use a new global species-level avian database to quantify the influence of elevational distribution (range, maximum and midpoint on extinction risk in birds at the global scale. We also tested this relationship within biogeographic realms, higher taxonomic levels, and across phylogenetic contrasts. Potential confounding variables (i.e. phylogenetic, distributional, morphological, life history and niche breadth were also tested and controlled for. We show that the three measures of elevational distribution are strong negative predictors of avian extinction risk, with elevational range comparable and complementary to that of geographical range size. Extinction risk was also found to be positively associated with body weight, development and adult survival, but negatively associated with reproduction and niche breadth. The robust and consistent findings from this study demonstrate the importance of elevational distribution as a key driver of variation in extinction dynamics in birds. Our results also highlight elevational distribution as a missing criterion in current schemes for quantifying extinction risk and setting species conservation priorities in birds. Further research is recommended to test for generality across non-avian taxa, which will require an advance in our knowledge of species' current elevational ranges and increased efforts to digitise and centralise such data.

  4. Experimental and Ecological Implications of Evening Bird Surveys in Stream-Riparian Ecosystems

    Science.gov (United States)

    Sullivan, S. Mažeika P.; Vierling, Kerri T.

    2009-10-01

    Stream-riparian ecosystems are dynamic and complex entities that can support high levels of bird assemblage abundance and diversity. The myriad patches (e.g., aquatic, floodplain, riparian) found in the riverscape habitat mosaic attract a unique mixture of aquatic, semiaquatic, riparian, and upland birds, each uniquely utilizing the river corridor. Whereas standard morning bird surveys are widely used across ecosystems, the variety of bird guilds and the temporal habitat partitioning that likely occur in stream-riparian ecosystems argue for the inclusion of evening surveys. At 41 stream reaches in Vermont and Idaho, USA, we surveyed bird assemblages using a combination of morning and evening fixed-width transect counts. Student’s paired t-tests showed that while bird abundance was not significantly different between morning and evening surveys, bird assemblage diversity (as measured by species richness, Shannon-Weiner’s index, and Simpson’s index) was significantly higher in the morning than in the evening. NMS ordinations of bird species and time (i.e., morning, evening) indicated that the structure of morning bird assemblages was different from that of evening assemblages. NMS further showed that a set of species was only found in evening surveys. The inclusion of evening counts in surveying bird assemblages in stream-riparian ecosystems has important experimental and ecological implications. Experimentally, the sole use of morning bird surveys may significantly underestimate the diversity and misrepresent the community composition of bird assemblages in these ecosystems. Ecologically, many of the birds detected in evening surveys were water-associated species that occupy high trophic levels and aerial insectivores that represent unique aquatic-terrestrial energy transfers.

  5. An interferometric-spectroscopic orbit for the binary HD 195987 Testing models of stellar evolution for metal-poor stars

    CERN Document Server

    Torres, G; Latham, D W; Pan, M; Stefanik, R P; Torres, Guillermo; Boden, Andrew F.; Latham, David W.; Pan, Margaret; Stefanik, Robert P.

    2002-01-01

    We report spectroscopic and interferometric observations of the moderately metal-poor double-lined binary system HD 195987, with an orbital period of 57.3 days. By combining our radial-velocity and visibility measurements we determine the orbital elements and derive absolute masses for the components of M(A) = 0.844 +/- 0.018 Msun and M(B) = 0.6650 +/- 0.0079 Msun, with relative errors of 2% and 1%, respectively. We also determine the orbital parallax, pi(orb) = 46.08 +/- 0.27 mas, corresponding to a distance of 21.70 +/- 0.13 pc. The parallax and the measured brightness difference between the stars in V, H, and K yield the component absolute magnitudes in those bands. We also estimate the effective temperatures of the stars as Teff(A) = 5200 +/- 100 K and Teff(B) = 4200 +/- 200 K. Together with detailed chemical abundance analyses from the literature giving [Fe/H] approximately -0.5 (corrected for binarity) and [alpha/Fe] = +0.36, we use these physical properties to test current models of stellar evolution f...

  6. Testing biological hypotheses with embodied robots: adaptations, accidents, and by-products in the evolution of vertebrates

    Directory of Open Access Journals (Sweden)

    Sonia F Roberts

    2014-11-01

    Full Text Available Evolutionary robotics allows biologists to test hypotheses about extinct animals. We modeled some of the first vertebrates, jawless fishes, in order to study the evolution of the trait after which vertebrates are named: vertebrae. We tested the hypothesis that vertebrae are an adaptation for enhanced feeding and fleeing performance. We created a population of autonomous embodied robots, Preyro, in which the number of vertebrae, N, were free to evolve. In addition, two other traits, the span of the caudal fin, b, and the predator detection threshold, ζ, a proxy for the lateral line sensory system, were also allowed to evolve. These three traits were chosen because they evolved early in vertebrates, are all potentially important in feeding and fleeing, and vary in form among species. Preyro took on individual identities in a given generation as defined by the population’s six diploid genotypes, Gi. Each Gi was a 3-tuple, with each element an integer specifying N, b, and, ζ. The small size of the population allowed for genetic drift to operate in concert with random mutation and mating; the presence of these mechanisms of chance provided an opportunity for N to evolve by accident. The presence of three evolvable traits provided an opportunity for direct selection on b and/or ζ to evolve N as a by-product linked trait correlation. In selection trials, different Gi embodied in Preyro attempted to feed at a light source and then flee to avoid a predator robot in pursuit. The fitness of each Gi was calculated from five different types of performance: speed, acceleration, distance to the light, distance to the predator, and the number of predator escapes initiated. In each generation, we measured the selection differential, the selection gradient, the strength of chance, and the indirect correlation selection gradient. These metrics allowed us to understand the relative contributions of the three mechanisms: direct selection, chance, and indirect

  7. Reservoir competence of native North American birds for the lyme disease spirochete, Borrelia burgdorfieri.

    Science.gov (United States)

    Ginsberg, Howard S; Buckley, P A; Balmforth, Maxon G; Zhioua, Elyes; Mitra, Shaibal; Buckley, Francine G

    2005-05-01

    Reservoir competence for the Lyme disease spirochete, Borrelia burgdorferi, was tested for six species of native North American birds: American robin, gray catbird, brown thrasher, eastern towhee, song sparrow, and northern cardinal. Wild birds collected by mist netting on Fire Island, NY, were held in a field laboratory in cages over water and locally collected larval ticks were placed on the birds, harvested from the water after engorgement, and tested for infection by direct fluorescentantibody staining after molting to the nymphal stage. American robins were competent reservoirs, infecting 16.1% of larvae applied to wild-caught birds, compared with 0% of control ticks placed on uninfected laboratory mice. Robins that were previously infected in the laboratory by nymphal feeding infected 81.8% of applied larvae. Wild-caught song sparrows infected 4.8% of applied larvae and 21.1% when infected by nymphal feeding. Results suggest moderate levels of reservoir competence for northern cardinals, lower levels for gray catbirds, and little evidence of reservoir competence for eastern towhees or brown thrashers. Lower infection rates in larvae applied to wild-caught birds compared with birds infected in the laboratory suggest that infected birds display temporal variability in infectiousness to larval ticks. Engorged larvae drop from birds abundantly during daylight, so the abundance of these bird species in the peridomestic environment suggests that they might contribute infected ticks to lawns and gardens.

  8. Automatic identification of bird targets with radar via patterns produced by wing flapping.

    Science.gov (United States)

    Zaugg, Serge; Saporta, Gilbert; van Loon, Emiel; Schmaljohann, Heiko; Liechti, Felix

    2008-09-01

    Bird identification with radar is important for bird migration research, environmental impact assessments (e.g. wind farms), aircraft security and radar meteorology. In a study on bird migration, radar signals from birds, insects and ground clutter were recorded. Signals from birds show a typical pattern due to wing flapping. The data were labelled by experts into the four classes BIRD, INSECT, CLUTTER and UFO (unidentifiable signals). We present a classification algorithm aimed at automatic recognition of bird targets. Variables related to signal intensity and wing flapping pattern were extracted (via continuous wavelet transform). We used support vector classifiers to build predictive models. We estimated classification performance via cross validation on four datasets. When data from the same dataset were used for training and testing the classifier, the classification performance was extremely to moderately high. When data from one dataset were used for training and the three remaining datasets were used as test sets, the performance was lower but still extremely to moderately high. This shows that the method generalizes well across different locations or times. Our method provides a substantial gain of time when birds must be identified in large collections of radar signals and it represents the first substantial step in developing a real time bird identification radar system. We provide some guidelines and ideas for future research.

  9. Reservoir competence of native North American birds for the Lyme disease spirochete, Borrelia burgdorferi

    Science.gov (United States)

    Ginsberg, Howard S.; Buckley, P.A.; Balmforth, Maxon G.; Zhioua, Elyes; Mitra, Shaibal; Buckley, Francine G.

    2005-01-01

    Reservoir competence for the Lyme disease spirochete, Borrelia burgdorferi, was tested for six species of native North American birds: American robin, gray catbird, brown thrasher, eastern towhee, song sparrow, and northern cardinal. Wild birds collected by mist netting on Fire Island, NY, were held in a field laboratory in cages over water and locally collected larval ticks were placed on the birds, harvested from the water after engorgement, and tested for infection by direct fluorescent-antibody staining after molting to the nymphal stage. American robins were competent reservoirs, infecting 16.1% of larvae applied to wild-caught birds, compared with 0% of control ticks placed on uninfected laboratory mice. Robins that were previously infected in the laboratory by nymphal feeding infected 81.8% of applied larvae. Wild-caught song sparrows infected 4.8% of applied larvae and 21.1% when infected by nymphal feeding. Results suggest moderate levels of reservoir competence for northern cardinals, lower levels for gray catbirds, and little evidence of reservoir competence for eastern towhees or brown thrashers. Lower infection rates in larvae applied to wild-caught birds compared with birds infected in the laboratory suggest that infected birds display temporal variability in infectiousness to larval ticks. Engorged larvae drop from birds abundantly during daylight, so the abundance of these bird species in the peridomestic environment suggests that they might contribute infected ticks to lawns and gardens.

  10. Birds and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, P.H.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

  11. Chernobyl birds have smaller brains.

    Directory of Open Access Journals (Sweden)

    Anders Pape Møller

    Full Text Available BACKGROUND: Animals living in areas contaminated by radioactive material from Chernobyl suffer from increased oxidative stress and low levels of antioxidants. Therefore, normal development of the nervous system is jeopardized as reflected by high frequencies of developmental errors, reduced brain size and impaired cognitive abilities in humans. Alternatively, associations between psychological effects and radiation have been attributed to post-traumatic stress in humans. METHODOLOGY/PRINCIPAL FINDING: Here we used an extensive sample of 550 birds belonging to 48 species to test the prediction that even in the absence of post-traumatic stress, there is a negative association between relative brain size and level of background radiation. We found a negative association between brain size as reflected by external head volume and level of background radiation, independent of structural body size and body mass. The observed reduction in brain size in relation to background radiation amounted to 5% across the range of almost a factor 5,000 in radiation level. Species differed significantly in reduction in brain size with increasing background radiation, and brain size was the only morphological character that showed a negative relationship with radiation. Brain size was significantly smaller in yearlings than in older individuals. CONCLUSIONS/SIGNIFICANCE: Low dose radiation can have significant effects on normal brain development as reflected by brain size and therefore potentially cognitive ability. The fact that brain size was smaller in yearlings than in older individuals implies that there was significant directional selection on brain size with individuals with larger brains experiencing a viability advantage.

  12. Comparative embryonic development of the skeleton of the domestic turkey (Meleagris gallopavo) and other galliform birds.

    Science.gov (United States)

    Maxwell, Erin E

    2008-01-01

    Ossification sequences are poorly known for birds in general, even for common domestic and experimental species. Such sequences constitute a rich source of data on character evolution, and may even provide phylogenetic information. It is not clear, however, what factors influence ossification sequences and what the relative importance of phylogeny is to the sequences. Galliformes constitute a good group to examine these variables. These birds are osteologically conservative, have precocial young, but have a broad spectrum of body sizes and incubation periods. Here, I describe the embryonic ossification of the skeleton in the domestic turkey (Meleagris gallopavo), and compare it to the domestic chicken (Gallus gallus) and the Japanese quail (Coturnix coturnix). Ossification sequences in this group are not affected by egg size or incubation period. They also appear to be independent of both the spatial location and the embryonic tissue from which the osteogenic cells originated. Accumulation of a wider sample of ossification sequences from more morphologically variable avian taxa will be necessary in order to test functional and phylogenetic effects.

  13. The shapes of bird beaks are highly controlled by nondietary factors.

    Science.gov (United States)

    Bright, Jen A; Marugán-Lobón, Jesús; Cobb, Samuel N; Rayfield, Emily J

    2016-05-10

    Bird beaks are textbook examples of ecological adaptation to diet, but their shapes are also controlled by genetic and developmental histories. To test the effects of these factors on the avian craniofacial skeleton, we conducted morphometric analyses on raptors, a polyphyletic group at the base of the landbird radiation. Despite common perception, we find that the beak is not an independently targeted module for selection. Instead, the beak and skull are highly integrated structures strongly regulated by size, with axes of shape change linked to the actions of recently identified regulatory genes. Together, size and integration account for almost 80% of the shape variation seen between different species to the exclusion of morphological dietary adaptation. Instead, birds of prey use size as a mechanism to modify their feeding ecology. The extent to which shape variation is confined to a few major axes may provide an advantage in that it facilitates rapid morphological evolution via changes in body size, but may also make raptors especially vulnerable when selection pressures act against these axes. The phylogenetic position of raptors suggests that this constraint is prevalent in all landbirds and that breaking the developmental correspondence between beak and braincase may be the key novelty in classic passerine adaptive radiations.

  14. Ecological Causes and Consequences of Intratropical Migration in Temperate-Breeding Migratory Birds.

    Science.gov (United States)

    Stutchbury, Bridget J M; Siddiqui, Raafia; Applegate, Kelly; Hvenegaard, Glen T; Mammenga, Paul; Mickle, Nanette; Pearman, Myrna; Ray, James D; Savage, Anne; Shaheen, Tim; Fraser, Kevin C

    2016-09-01

    New discoveries from direct tracking of temperate-breeding passerines show that intratropical migration (ITM) occurs in a growing number of species, which has important implications for understanding their evolution of migration, population dynamics, and conservation needs. Our large sample size ([Formula: see text]) for purple martins (Progne subis subis) tracked with geolocators to winter sites in Brazil, combined with geolocator deployments at breeding colonies across North America, allowed us to test hypotheses for ITM, something which has not yet been possible to do for other species. ITM in purple martins was not obligate; only 44% of individuals exhibited ITM, and movements were not coordinated in time or space. We found no evidence to support the resource hypothesis; rainfall and temperature experienced by individual birds during their last 2 weeks at their first roost site were similar to conditions at their second roost site after ITM. Birds generally migrated away from the heavily forested northwestern Amazon to less forested regions to the south and east. ITM in this aerial insectivore appears to support the competition-avoidance hypothesis and may be triggered by increasing local density in the core wintering region. Full life cycle models and migratory networks will need to incorporate ITM to properly address seasonal carryover effects and identify which wintering regions are most important for conservation.

  15. THE BIRD PATICA IN BULGARIAN

    Directory of Open Access Journals (Sweden)

    M. N. Belova

    2015-01-01

    Full Text Available The paper observes some words for waterfowls (aquatic birds occurring exclusively in South Slavic languages: пат, патка, пате, патица 'duck, goose' and some of their derivatives. The root in these words is generally attributed to common Slavic pъt'bird', but the origin of the vowel timbre (a instead of ъ is unclear. Furthermore, this root could also be found in Eastern and rarely Western Slavic names for another bird 'куропатка' ('Perdix'.  Here all of the attempts for explaining the root vowel are summarized; also I propose a new convergence with the turkish root pat-/pač-, which could have had strong influence on the root vowel in a number of derivatives in Bulgarian, Macedonian, Serbian and Croatian.

  16. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

    2015-01-01

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... on Invasive Alien Species implemented in January 2015 establishes a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

  17. Testing the Effect of Internal Genes Derived from a Wild-Bird-Origin H9N2 Influenza A Virus on the Pathogenicity of an A/H7N9 Virus.

    Science.gov (United States)

    Su, Wen; Wang, Chengmin; Luo, Jing; Zhao, Yuliang; Wu, Yan; Chen, Lin; Zhao, Na; Li, Meng; Xing, Chao; Liu, Huimin; Zhang, Hong; Chang, Yung-fu; Li, Tianxian; Ding, Hua; Wan, Xiufeng; He, Hongxuan

    2015-09-22

    Since 2013, avian influenza A(H7N9) viruses have diversified into multiple lineages by dynamically reassorting with other viruses, especially H9N2, in Chinese poultry. Despite concerns about the pandemic threat posed by H7N9 viruses, little is known about the biological properties of H7N9 viruses that may recruit internal genes from genetically distinct H9N2 viruses circulating among wild birds. Here, we generated 63 H7N9 reassortants derived from an avian H7N9 and a wild-bird-origin H9N2 virus. Compared with the wild-type parent, 25/63 reassortants had increased pathogenicity in mice. A reassortant containing PB1 of the H9N2 virus was highly lethal to mice and chickens but was not transmissible to guinea pigs by airborne routes; however, three substitutions associated with adaptation to mammals conferred airborne transmission to the virus. The emergence of the H7N9-pandemic reassortant virus highlights that continuous monitoring of H7N9 viruses is needed, especially at the domestic poultry/wild bird interface.

  18. Testing the Effect of Internal Genes Derived from a Wild-Bird-Origin H9N2 Influenza A Virus on the Pathogenicity of an A/H7N9 Virus

    Directory of Open Access Journals (Sweden)

    Wen Su

    2015-09-01

    Full Text Available Since 2013, avian influenza A(H7N9 viruses have diversified into multiple lineages by dynamically reassorting with other viruses, especially H9N2, in Chinese poultry. Despite concerns about the pandemic threat posed by H7N9 viruses, little is known about the biological properties of H7N9 viruses that may recruit internal genes from genetically distinct H9N2 viruses circulating among wild birds. Here, we generated 63 H7N9 reassortants derived from an avian H7N9 and a wild-bird-origin H9N2 virus. Compared with the wild-type parent, 25/63 reassortants had increased pathogenicity in mice. A reassortant containing PB1 of the H9N2 virus was highly lethal to mice and chickens but was not transmissible to guinea pigs by airborne routes; however, three substitutions associated with adaptation to mammals conferred airborne transmission to the virus. The emergence of the H7N9-pandemic reassortant virus highlights that continuous monitoring of H7N9 viruses is needed, especially at the domestic poultry/wild bird interface.

  19. Breeding bird density does not drive vocal individuality

    Institute of Scientific and Technical Information of China (English)

    Daniel T.BLUMSTEIN; Douglas R.MCCLAIN; Carrie DE JESUS; Gustavo ALARC(O)N-NIETO

    2012-01-01

    Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality.Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species,and how social group size influenced individuality in sciurid rodents.Since sociality is an important driver of individuality,we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods.We used Beecher's information statistic to quantify individuality,and we examined the relationship between bird density (calculated with point-counts) and vocal individuality on seven species of passerines.We found non-significant relationships between breeding bird density and vocal individuality whether regressions were fitted on species values,or on phylogenetically-independent contrast values.From these results,we infer that while individuality may be explained by social factors,breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations.

  20. Fuglene. Audubon: Birds of America

    DEFF Research Database (Denmark)

    Schlichtkrull, Torsten

    2010-01-01

    The Royal Library owns one of the most exceptional works in book history, an original edition of John James Audubon Birds of America. This edition, in a format called “double elephant folio” was published from 1827 to 1838. On basis of existing literature, this article briefly describes the work...... the Royal Library and the University Library, joined the library cooperation of the 1800’s on an equal standing with the other two libraries. The Classen’s Library and the library’s founder, industrialist JF Classen are described briefly in this article. Due to two library mergers the Birds of America...

  1. Chemical compass for bird navigation

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Hore, Peter J.; Ritz, Thorsten

    2014-01-01

    Migratory birds travel spectacular distances each year, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the detection...... increased interest following the proposal in 2000 that free radical chemistry could occur in the bird's retina initiated by photoexcitation of cryptochrome, a specialized photoreceptor protein. In the present paper we review the important physical and chemical constraints on a possible radical...

  2. How safe is the use of chlorpyrifos: Revelations through its effect on layer birds

    Directory of Open Access Journals (Sweden)

    P. P. Singh

    2016-07-01

    Full Text Available Aim: The present study was aimed to investigate the immunological competence of chlorpyrifos (CPF insecticide after oral administration in layer chickens. Materials and Methods: A total of 20 White Leghorn birds were given CPF in drinking water at 0.3 ppm/bird/day (no observable effect level dose for a period of 3-month. Immune competence status of layer birds and chicks hatched from CPF-treated birds were estimated at 15 days interval in layer birds and monthly interval in chicks using immunological and biochemical parameters. Results: There was a significant decrease in values of total leukocytes count, absolute lymphocyte count, absolute heterophil count, total serum protein, serum albumin, serum globulin, and serum gamma globulin in the birds treated with CPF as compared to control. Similarly, immune competence tests such as lymphocyte stimulation test, oxidative burst assay, and enzyme-linked immunosorbent assay tests indicated lower immunity in birds treated with CPF as compared to control. Subsequently, chicks produced from CPF-treated birds were also examined for immune competence, but no significant difference was observed between chicks of both the groups. Conclusion: The exposure to CPF produced hemo-biochemical and other changes that could be correlated with changes in the immunological profile of layer chickens suggesting total stoppage of using CPF in poultry sheds.

  3. How safe is the use of chlorpyrifos: Revelations through its effect on layer birds

    Science.gov (United States)

    Singh, P. P.; Kumar, Ashok; Chauhan, R. S.; Pankaj, P. K.

    2016-01-01

    Aim: The present study was aimed to investigate the immunological competence of chlorpyrifos (CPF) insecticide after oral administration in layer chickens. Materials and Methods: A total of 20 White Leghorn birds were given CPF in drinking water at 0.3 ppm/bird/day (no observable effect level dose) for a period of 3-month. Immune competence status of layer birds and chicks hatched from CPF-treated birds were estimated at 15 days interval in layer birds and monthly interval in chicks using immunological and biochemical parameters. Results: There was a significant decrease in values of total leukocytes count, absolute lymphocyte count, absolute heterophil count, total serum protein, serum albumin, serum globulin, and serum gamma globulin in the birds treated with CPF as compared to control. Similarly, immune competence tests such as lymphocyte stimulation test, oxidative burst assay, and enzyme-linked immunosorbent assay tests indicated lower immunity in birds treated with CPF as compared to control. Subsequently, chicks produced from CPF-treated birds were also examined for immune competence, but no significant difference was observed between chicks of both the groups. Conclusion: The exposure to CPF produced hemo-biochemical and other changes that could be correlated with changes in the immunological profile of layer chickens suggesting total stoppage of using CPF in poultry sheds. PMID:27536038

  4. Effect of Habitat Complexity on Richness, Abundance and Distributional Pattern of Forest Birds

    Science.gov (United States)

    Ghadiri Khanaposhtani, Maryam; Kaboli, Mohammad; Karami, Mahmoud; Etemad, Vahid

    2012-08-01

    Structurally complex forests provide more diverse conditions in comparison to homogenous forests because of greater variety of microhabitats and trees. This study assesses the association of bird species richness, abundance, and distributional pattern with habitat complexity (HC) in Kheyrud Forest in the north of Iran. Birds were surveyed during spring 2009 by 100 point counts. In each point count six habitat features related to the index of HC were computed and scored from 0 to 3. Then the scores were summed and divided into two groups of low and high complexity, HC ≤ 6 and HC > 6, respectively. To compare bird richness and abundance in different HCs, a two sample t-test was used. Presence and absence of bird species at each plot as a dependent variable were compared with the vegetation characteristics as an independent variable by means of the Canonical Correspondence Analysis. The results revealed bird species richness and abundance were significantly higher in more complex habitats. Bird species can be divided into two groups, the first group including species which associated with late successional stages and the second group, species belonging to early successional stages. Numbers of birds belonging to the first group declined in less complex forests, whereas the numbers of birds belonging to the second group increased. At the stand scale, our results reveal that bird abundance and richness are strongly associated with the complexity of vegetation structure in the study area.

  5. Do 'Early Birds' Get the Healthier Worm?

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_163902.html Do 'Early Birds' Get the Healthier Worm? Late-to-bed types ... 2017 FRIDAY, March 3, 2017 (HealthDay News) -- Early birds may have a leg up over night owls ...

  6. Birds observed at Shemya Island, Aleutian Islands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers Shemya Island bird surveys. The reports outline migrant bird activity during August 31 to October 3, 1977. The purpose of the study was to survey...

  7. Cape Romain National Wildlife Refuge Bird List

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This bird list includes 293 species of birds which have been recorded on the refuge, principally on Bulls Island, and is based on observations by refuge personnel...

  8. Wavelets in Recognition of Bird Sounds

    Directory of Open Access Journals (Sweden)

    Selin Arja

    2007-01-01

    Full Text Available This paper presents a novel method to recognize inharmonic and transient bird sounds efficiently. The recognition algorithm consists of feature extraction using wavelet decomposition and recognition using either supervised or unsupervised classifier. The proposed method was tested on sounds of eight bird species of which five species have inharmonic sounds and three reference species have harmonic sounds. Inharmonic sounds are not well matched to the conventional spectral analysis methods, because the spectral domain does not include any visible trajectories that computer can track and identify. Thus, the wavelet analysis was selected due to its ability to preserve both frequency and temporal information, and its ability to analyze signals which contain discontinuities and sharp spikes. The shift invariant feature vectors calculated from the wavelet coefficients were used as inputs of two neural networks: the unsupervised self-organizing map (SOM and the supervised multilayer perceptron (MLP. The results were encouraging: the SOM network recognized 78% and the MLP network 96% of the test sounds correctly.

  9. Optimal Foraging by Birds: Experiments for Secondary & Postsecondary Students

    Science.gov (United States)

    Pecor, Keith W.; Lake, Ellen C.; Wund, Matthew A.

    2015-01-01

    Optimal foraging theory attempts to explain the foraging patterns observed in animals, including their choice of particular food items and foraging locations. We describe three experiments designed to test hypotheses about food choice and foraging habitat preference using bird feeders. These experiments can be used alone or in combination and can…

  10. Bat predation on nocturnally migrating birds

    OpenAIRE

    Ibáñez, Carlos; Juste, Javier; García-Mudarra, Juan L.; Agirre-Mendi, Pablo T.

    2001-01-01

    Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concen- trate and cross over the world’s temperate regions during migra- tion, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures a...

  11. 76 FR 48693 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Science.gov (United States)

    2011-08-08

    ... August 8, 2011 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded... RIN 1018-AX34 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain...

  12. 76 FR 54051 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2011-08-30

    ... Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations; Final Rule #0;#0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service,...

  13. 77 FR 53117 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2012-08-30

    ... Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations; Final Rule #0;#0...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife...

  14. 75 FR 47681 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Science.gov (United States)

    2010-08-06

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting... INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded Lands for the 2010-11...

  15. 78 FR 52657 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2013-08-23

    ... Bird Hunting; Final Frameworks for Early Season Migratory Bird Hunting Regulations; Final Rule #0;#0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service,...

  16. Birds and Bird Habitat: What Are the Risks from Industrial Wind Turbine Exposure?

    Science.gov (United States)

    Sprague, Terry; Harrington, M. Elizabeth; Krogh, Carmen M. E.

    2011-01-01

    Bird kill rate and disruption of habitat has been reported when industrial wind turbines are introduced into migratory bird paths or other environments. While the literature could be more complete regarding the documentation of negative effects on birds and bird habitats during the planning, construction, and operation of wind power projects,…

  17. The Bird Box Survey Project

    Science.gov (United States)

    Willis, Patrick

    2014-01-01

    When high school students are asked what's the best part of science class, many will say it's the field trips. Students enjoy engaging in authentic, community-based science outside the classroom. To capitalize on this, Patrick Willis created the Bird Box Survey Project for his introductory field biology class. The project takes students…

  18. The Breeding Bird Survey, 1966

    Science.gov (United States)

    Robbins, C.S.; Van Velzen, W.T.

    1967-01-01

    A Breeding Bird Survey of a large section on North America was conducted during June 1966. Cooperators ran a total of 585 Survey routes in 26 eastern States and 4 Canadian Provinces. Future coverage of established routes will enable changes in the abundance of North American breeding birds to be measured. Routes are selected at random on the basis of one-degree blocks of latitude and longitude. Each 241/2-mile route, with 3-minute stops spaced one-half mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms and the data are then transferred to machine punch cards. The average number of birds per route is tabulated by State, along with the total number of each species and the percent of routes and stops upon which they were recorded. Maps are presented showing the range and abundance of selected species. Also, a year-to-year comparison is made of populations of selected species on Maryland routes in 1965 and 1966.

  19. Physiological adaptation in desert birds

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  20. Notes on some Sumatran birds

    NARCIS (Netherlands)

    Junge, G.C.A.

    1948-01-01

    During the war I was able to identify some collections of birds from Sumatra, present in the Leiden Museum. These collections were brought together by E. Jacobson and W. C. van Heurn in the Padang Highlands in 1013; by W. Groeneveldt in the same area in 1914 and 1915; bij L. P. Cosquino de Bussy and

  1. Managing a Bird Flu Pandemic

    Science.gov (United States)

    Stover, Del

    2006-01-01

    Concern about a possible bird flu pandemic has grown in the medical community with the spread of the avian flu virus around the globe. Health officials say there is no immediate threat but add that an influenza pandemic occurs every 30 to 40 years, and prudence demands planning now. That planning will increasingly involve local school officials,…

  2. Incorporation of Deepwater Horizon oil in a terrestrial bird

    Science.gov (United States)

    Bonisoli-Alquati, A.; Stouffer, P. C.; Turner, R. E.; Woltmann, S.; Taylor, S. S.

    2016-11-01

    Carbon isotopic evidence revealed Deepwater Horizon (DWH) oil entering coastal planktonic and lower terrestrial food webs. The integration of spilled oil into higher terrestrial trophic levels, however, remains uncertain. We measured radiocarbon (14C) and stable carbon (13C) in seaside sparrow (Ammodramus maritimus) feathers and crop contents. Lower 14C and 13C values in feathers and crop contents of birds from contaminated areas indicated incorporation of carbon from oil. Our results, although based on a small sample of birds, thus reveal a food-web link between oil exposure and a terrestrial ecosystem. They also suggest that the reduction in reproductive success previously documented in the same population might be due to the (direct) toxic effect of oil exposure, rather than to (indirect) ecological effects. We recommend future studies test our results by using larger samples of birds from a wider area in order to assess the extent and implications of DWH oil incorporation into the terrestrial food web.

  3. Molecular Characterization of Toxoplasma gondii from Bird Hosts

    Directory of Open Access Journals (Sweden)

    N Zia-Ali

    2005-08-01

    Full Text Available The determination of Toxoplasma gondii prevalence in a variety of domestic birds is thought as a good indicator of distribution of T.gondii ooccyts in the environment. To verify the potential role of domestic birds in circulating toxoplasmosis in Iran, the present study was conducted in Mazandaran Provinces, northern Iran. Latex agglutination test (LA antibodies were found in 25 of 58 free-ranging chickens (Gallus domesticus and ducks (Anas sp.. Also, viable T. gondii was isolated from 7 of 25 seropositive chickens and ducks by bioassay of their brains and hearts into mice. Most of the isolated strains were avirulant to mice. Genotyping of T.gondii isolates using Multiplex PCR for 5 microsatellite markers indicated that 7 isolates were type III. In this study type II and III isolates and mixed genotypes were not found. This study showed that domestic birds could have a potential role in transmitting toxoplasmosis to humans in Iran.

  4. 14 CFR 29.631 - Bird strike.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  5. Epidemiologic characterization of Colorado backyard bird flocks.

    Science.gov (United States)

    Smith, Emily I; Reif, John S; Hill, Ashley E; Slota, Katharine E; Miller, Ryan S; Bjork, Kathe E; Pabilonia, Kristy L

    2012-06-01

    Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds.

  6. Velogenic Newcastle disease in imported caged birds.

    Science.gov (United States)

    Clavijo, A; Robinson, Y; Booth, T; Munroe, F

    2000-05-01

    Velogenic Newcastle disease was diagnosed in pet birds intended for importation into Canada. Virological and histopathological examination confirmed the presence of the disease. The group of birds was denied entry into Canada. Similar birds illegally imported are a potential source of velogenic Newcastle disease virus and are a threat to domestic poultry.

  7. Velogenic Newcastle disease in imported caged birds.

    OpenAIRE

    Clavijo, A.; Robinson, Y; Booth, T.; Munroe, F

    2000-01-01

    Velogenic Newcastle disease was diagnosed in pet birds intended for importation into Canada. Virological and histopathological examination confirmed the presence of the disease. The group of birds was denied entry into Canada. Similar birds illegally imported are a potential source of velogenic Newcastle disease virus and are a threat to domestic poultry.

  8. I LIKE LISTENING TO BIRDS SINGING

    Institute of Scientific and Technical Information of China (English)

    刘向勤; 廖明娟

    2002-01-01

    Every early morning, birds' happy singing wakes me up. I get dressed quickly and have a wash and brush up, then watch birds and listen to them singing happily in the trees. The singing of different kinds of birds sounds like a piece of beautiful symphonic music. Birds’singing makes me relaxed and happy and it also recalls me something of the Past.

  9. The Physics of Bird Flight: An Experiment

    Science.gov (United States)

    Mihail, Michael D.; George, Thomas F.; Feldman, Bernard J.

    2008-01-01

    This article describes an experiment that measures the forces acting on a flying bird during takeoff. The experiment uses a minimum of equipment and only an elementary knowledge of kinematics and Newton's second law. The experiment involves first digitally videotaping a bird during takeoff, analyzing the video to determine the bird's position as a…

  10. DNA barcoding of Dutch birds

    Directory of Open Access Journals (Sweden)

    Mansour Aliabadian

    2013-12-01

    Full Text Available The mitochondrial cytochrome c-oxidase subunit I (COI can serve as a fast and accurate marker for the identification of animal species, and has been applied in a number of studies on birds. We here sequenced the COI gene for 387 individuals of 147 species of birds from the Netherlands, with 83 species being represented by >2 sequences. The Netherlands occupies a small geographic area and 95% of all samples were collected within a 50 km radius from one another. The intraspecific divergences averaged 0.29% among this assemblage, but most values were lower; the interspecific divergences averaged 9.54%. In all, 95% of species were represented by a unique barcode, with 6 species of gulls and skua (Larus and Stercorariusat least one shared barcode. This is best explained by these species representing recent radiations with ongoing hybridization. In contrast, one species, the Lesser Whitethroat Sylvia curruca showed deep divergences, averaging 5.76% and up to 8.68% between individuals. These possibly represent two distinct taxa, S. curruca and S. blythi, both clearly separated in a haplotype network analysis. Our study adds to a growing body of DNA barcodes that have become available for birds, and shows that a DNA barcoding approach enables to identify known Dutch bird species with a very high resolution. In addition some species were flagged up for further detailed taxonomic investigation, illustrating that even in ornithologically well-known areas such as the Netherlands, more is to be learned about the birds that are present.

  11. Ontogeny of aerial righting and wing flapping in juvenile birds

    CERN Document Server

    Evangelista, Dennis; Huynh, Tony; Krivitskiy, Igor; Dudley, Robert

    2014-01-01

    Mechanisms of aerial righting in juvenile Chukar Partridge (Alectoris chukar) were studied from hatching through 14 days post hatching (dph). Asymmetric movements of the wings were used from 1 to 8 dph to effect progressively more successful righting behaviour via body roll. Following 8 dph, wing motions transitioned to bilaterally symmetric flapping that yielded aerial righting via nose down pitch, along with substantial increases in vertical force production during descent. Ontogenetically, the use of such wing motions to effect aerial righting precedes both symmetric flapping and a previously documented behaviour in chukar (i.e., wing assisted incline running) hypothesized to be relevant to incipient flight evolution in birds. These findings highlight the importance of asymmetric wing activation and controlled aerial manoeuvres during bird development, and are potentially relevant to understanding the origins of avian flight.

  12. Mitogenomic analyses propose positive selection in mitochondrial genes for high-altitude adaptation in galliform birds.

    Science.gov (United States)

    Zhou, Taicheng; Shen, Xuejuan; Irwin, David M; Shen, Yongyi; Zhang, Yaping

    2014-09-01

    Galliform birds inhabit very diverse habitats, including plateaus that are above 3000 m in altitude. At high altitude, lower temperature and hypoxia are two important factors influencing survival. Mitochondria, as the ultimate oxygen transductor, play an important role in aerobic respiration through oxidative phosphorylation (OXPHOS). We analyzed the mitochondrial genomes of six high-altitude phasianidae birds and sixteen low-altitude relatives in an attempt to determine the role of mitochondrial genes in high-altitude adaptation. We reconstructed the phylogenetic relationships of these phasianidae birds and relatives and found at least four lineages that independently occupied this high-altitude habitat. Selective analyses revealed significant evidence for positive selection in the genes ND2, ND4, and ATP6 in three of the high-altitude lineages. This result strongly suggests that adaptive evolution of mitochondrial genes played a critical role during the independent acclimatization to high altitude by galliform birds.

  13. SUBMONTANE FOREST AT BANTIMURUNG BULUSARAUNG NATIONAL PARK: HOTSPOT OF BIRD DIVERSITY AND ITS MANAGEMENT CONSERVATION

    Directory of Open Access Journals (Sweden)

    Indra A.S.L.P. Putri

    2015-09-01

    Full Text Available Submontane forest is considered as one of the biodiversity hotspot.  Scientific information on bird diversity in this forest, however are lacking.  The aim of this research was to find out submontane forest bird diversity and its conservation management.  The research was carried out in three forests areas at Bantimurung Bulusaraung National Park submontane forest.  Point Count method was used to observe bird population. Data were analyzed using Shannon-Weiner diversity index, Pielou Evenness index, Simpson dominance index, Margalef species richness index, and Sorensen Similarity index. The significance different between the number of individual bird was tested using Kolmogorov-Smirnov test.  The result showed that submontane forest at Bantimurung Bulusaraung National Park is rich in bird diversity, bird endemic species and protected bird species.  There was a significant different on the number of individual bird at several human disturbance levels.  Based on these conditions, it is important to enhance understanding of the local people regarding zonation and develop cooperation with many stakeholders to increase the local community awareness concerning forest conservation. It is also necessary to ensure the sustainability of the National Park’s conservation program to maintain the submontane forest conservation.

  14. An unexpectedly long history of sexual selection in birds-of-paradise

    Directory of Open Access Journals (Sweden)

    Christidis Les

    2009-09-01

    Full Text Available Abstract Background The birds-of-paradise (Paradisaeidae form one of the most prominent avian examples of sexual selection and show a complex biogeographical distribution. The family has accordingly been used as a case-study in several significant evolutionary and biogeographical syntheses. As a robust phylogeny of the birds-of-paradise has been lacking, these hypotheses have been tentative and difficult to assess. Here we present a well supported species phylogeny with divergence time estimates of the birds-of-paradise. We use this to assess if the rates of the evolution of sexually selected traits and speciation have been excessively high within the birds-of-paradise, as well as to re-interpret biogeographical patterns in the group. Results The phylogenetic results confirm some traditionally recognized relationships but also suggest novel ones. Furthermore, we find that species pairs are geographically more closely linked than previously assumed. The divergence time estimates suggest that speciation within the birds-of-paradise mainly took place during the Miocene and the Pliocene, and that several polygynous and morphologically homogeneous genera are several million years old. Diversification rates further suggest that the speciation rate within birds-of-paradise is comparable to that of the enitre core Corvoidea. Conclusion The estimated ages of morphologically homogeneous and polygynous genera within the birds-of-paradise suggest that there is no need to postulate a particularly rapid evolution of sexually selected morphological traits. The calculated divergence rates further suggest that the speciation rate in birds-of-paradise has not been excessively high. Thus the idea that sexual selection could generate high speciation rates and rapid changes in sexual ornamentations is not supported by our birds-of-paradise data. Potentially, hybridization and long generation times in polygynous male birds-of-paradise have constrained morphological

  15. A comparison of auditory brainstem responses across diving bird species

    Science.gov (United States)

    Crowell, Sara E.; Berlin, Alicia; Carr, Catherine E; Olsen, Glenn H.; Therrien, Ronald E; Yannuzzi, Sally E; Ketten, Darlene R

    2015-01-01

    There is little biological data available for diving birds because many live in hard-to-study, remote habitats. Only one species of diving bird, the black-footed penguin (Spheniscus demersus), has been studied in respect to auditory capabilities (Wever et al., Proc Natl Acad Sci USA 63:676–680, 1969). We, therefore, measured in-air auditory threshold in ten species of diving birds, using the auditory brainstem response (ABR). The average audiogram obtained for each species followed the U-shape typical of birds and many other animals. All species tested shared a common region of the greatest sensitivity, from 1000 to 3000 Hz, although audiograms differed significantly across species. Thresholds of all duck species tested were more similar to each other than to the two non-duck species tested. The red-throated loon (Gavia stellata) and northern gannet (Morus bassanus) exhibited the highest thresholds while the lowest thresholds belonged to the duck species, specifically the lesser scaup (Aythya affinis) and ruddy duck (Oxyura jamaicensis). Vocalization parameters were also measured for each species, and showed that with the exception of the common eider (Somateria mollisima), the peak frequency, i.e., frequency at the greatest intensity, of all species' vocalizations measured here fell between 1000 and 3000 Hz, matching the bandwidth of the most sensitive hearing range.

  16. A numerical model for bird strike on sidewall structure of an aircraft nose

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Li Yulong; Gao Xiaosheng; Yu Xiancheng

    2014-01-01

    In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH) and finite element (FE) method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH-FE method is developed to simulate the bird-strike tests and a numerical model is established using a commercial software PAM-CRASH. The bird model shows no signs of instability and correctly modeled the break-up of the bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH-FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of bird strike.

  17. A numerical model for bird strike on sidewall structure of an aircraft nose

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2014-06-01

    Full Text Available In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH and finite element (FE method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the bird-strike tests and a numerical model is established using a commercial software PAM-CRASH. The bird model shows no signs of instability and correctly modeled the break-up of the bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH–FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of bird strike.

  18. Mapping global diversity patterns for migratory birds.

    Science.gov (United States)

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H M; Rodrigues, Ana S L

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  19. Urban Bird Feeding: Connecting People with Nature.

    Directory of Open Access Journals (Sweden)

    Daniel T C Cox

    Full Text Available At a time of unprecedented biodiversity loss, researchers are increasingly recognizing the broad range of benefits provided to humankind by nature. However, as people live more urbanized lifestyles there is a progressive disengagement with the natural world that diminishes these benefits and discourages positive environmental behaviour. The provision of food for garden birds is an increasing global phenomenon, and provides a readily accessible way for people to counter this trend. Yet despite its popularity, quite why people feed birds remains poorly understood. We explore three loosely defined motivations behind bird feeding: that it provides psychological benefits, is due to a concern about bird welfare, and/or is due to a more general orientation towards nature. We quantitatively surveyed households from urban towns in southern England to explore attitudes and actions towards garden bird feeding. Each household scored three Likert statements relating to each of the three motivations. We found that people who fed birds regularly felt more relaxed and connected to nature when they watched garden birds, and perceived that bird feeding is beneficial for bird welfare while investing time in minimising associated risks. Finally, feeding birds may be an expression of a wider orientation towards nature. Overall, we found that the feelings of being relaxed and connected to nature were the strongest drivers. As urban expansion continues both to threaten species conservation and to change peoples' relationship with the natural world, feeding birds may provide an important tool for engaging people with nature to the benefit of both people and conservation.

  20. Mapping global diversity patterns for migratory birds.

    Directory of Open Access Journals (Sweden)

    Marius Somveille

    Full Text Available Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  1. Do unpaved, low-traffic roads affect bird communities?

    Science.gov (United States)

    Mammides, Christos; Kounnamas, Constantinos; Goodale, Eben; Kadis, Costas

    2016-02-01

    Unpaved, low traffic roads are often assumed to have minimal effects on biodiversity. To explore this assertion, we sampled the bird communities in fifteen randomly selected sites in Pafos Forest, Cyprus and used multiple regression to quantify the effects of such roads on the total species richness. Moreover, we classified birds according to their migratory status and their global population trends, and tested each category separately. Besides the total length of unpaved roads, we also tested: a. the site's habitat diversity, b. the coefficient of variation in habitat (patch) size, c. the distance to the nearest agricultural field, and d. the human population size of the nearest village. We measured our variables at six different distances from the bird point-count locations. We found a strong negative relationship between the total bird richness and the total length of unpaved roads. The human population size of the nearest village also had a negative effect. Habitat diversity was positively related to species richness. When the categories were tested, we found that the passage migrants were influenced more by the road network while resident breeders were influenced by habitat diversity. Species with increasing and stable populations were only marginally affected by the variables tested, but the effect of road networks on species with decreasing populations was large. We conclude that unpaved and sporadically used roads can have detrimental effects on the bird communities, especially on vulnerable species. We propose that actions are taken to limit the extent of road networks within protected areas, especially in sites designated for their rich avifauna, such as Pafos Forest, where several of the affected species are species of European and global importance.

  2. Long lifespans have evolved with long and monounsaturated fatty acids in birds.

    Science.gov (United States)

    Galván, Ismael; Naudí, Alba; Erritzøe, Johannes; Møller, Anders P; Barja, Gustavo; Pamplona, Reinald

    2015-10-01

    The evolution of lifespan is a central question in evolutionary biology, begging the question why there is so large variation among taxa. Specifically, a central quest is to unravel proximate causes of ageing. Here, we show that the degree of unsaturation of liver fatty acids predicts maximum lifespan in 107 bird species. In these birds, the degree of fatty acid unsaturation is positively related to maximum lifespan across species. This is due to a positive effect of monounsaturated fatty acid content, while polyunsaturated fatty acid content negatively correlates with maximum lifespan. Furthermore, fatty acid chain length unsuspectedly increases with maximum lifespan independently of degree of unsaturation. These findings tune theories on the proximate causes of ageing while providing evidence that the evolution of lifespan in birds occurs in association with fatty acid profiles. This suggests that studies of proximate and ultimate questions may facilitate our understanding of these central evolutionary questions.

  3. Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage.

    Science.gov (United States)

    Benson, Roger B J; Campione, Nicolás E; Carrano, Matthew T; Mannion, Philip D; Sullivan, Corwin; Upchurch, Paul; Evans, David C

    2014-05-01

    Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of

  4. Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage.

    Directory of Open Access Journals (Sweden)

    Roger B J Benson

    2014-05-01

    Full Text Available Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large

  5. BIRD COMMUNITIES AND HABITAT AS ECOLOGICAL INDICATORS OF FOREST CONDITION IN REGIONAL MONITORING

    Science.gov (United States)

    Ecological indicators for long-term monitoring programs are needed to detect and assess changing environmental conditions, We developed and tested community-level environmental indicators for monitoring forest bird populations and associated habitat. We surveyed 197 sampling plo...

  6. Is sociality required for the evolution of communicative complexity? Evidence weighed against alternative hypotheses in diverse taxonomic groups.

    Science.gov (United States)

    Ord, Terry J; Garcia-Porta, Joan

    2012-07-05

    Complex social communication is expected to evolve whenever animals engage in many and varied social interactions; that is, sociality should promote communicative complexity. Yet, informal comparisons among phylogenetically independent taxonomic groups seem to cast doubt on the putative role of social factors in the evolution of complex communication. Here, we provide a formal test of the sociality hypothesis alongside alternative explanations for the evolution of communicative complexity. We compiled data documenting variations in signal complexity among closely related species for several case study groups--ants, frogs, lizards and birds--and used new phylogenetic methods to investigate the factors underlying communication evolution. Social factors were only implicated in the evolution of complex visual signals in lizards. Ecology, and to some degree allometry, were most likely explanations for complexity in the vocal signals of frogs (ecology) and birds (ecology and allometry). There was some evidence for adaptive evolution in the pheromone complexity of ants, although no compelling selection pressure was identified. For most taxa, phylogenetic null models were consistently ranked above adaptive models and, for some taxa, signal complexity seems to have accumulated in species via incremental or random changes over long periods of evolutionary time. Becoming social presumably leads to the origin of social communication in animals, but its subsequent influence on the trajectory of signal evolution has been neither clear-cut nor general among taxonomic groups.

  7. The Strategy to Survive Primary Malaria Infection: An Experimental Study on Behavioural Changes in Parasitized Birds.

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    Andrey Mukhin

    Full Text Available Avian malaria parasites (Haemosporida, Plasmodium are of cosmopolitan distribution, and they have a significant impact on vertebrate host fitness. Experimental studies show that high parasitemia often develops during primary malaria infections. However, field studies only occasionally reveal high parasitemia in free-living birds sampled using the traditional methods of mist-netting or trapping, and light chronic infections predominate. The reason for this discrepancy between field observation and experimental data remains insufficiently understood. Since mist-netting is a passive capture method, two main parameters determine its success in sampling infected birds in wildlife, i. e. the presence of parasitized birds at a study site and their mobility. In other words, the trapping probability depends on the survival rate of birds and their locomotor activity during infection. Here we test (1 the mortality rate of wild birds infected with Plasmodium relictum (the lineage pSGS1, (2 the changes in their behaviour during presence of an aerial predator, and (3 the changes in their locomotor activity at the stage of high primary parasitemia.We show that some behavioural features which might affect a bird's survival during a predator attack (time of reaction, speed of flush flight and take off angle did not change significantly during primary infection. However, the locomotor activity of infected birds was almost halved compared to control (non-infected birds during the peak of parasitemia. We report (1 the markedly reduced mobility and (2 the 20% mortality rate caused by P. relictum and conclude that these factors are responsible for the underrepresentation of birds in mist nets and traps during the stage of high primary parasitemia in wildlife. This study indicates that the widespread parasite, P. relictum (pSGS1 influences the behaviour of birds during primary parasitemia. Experimental studies combined with field observations are needed to better

  8. Exploiting Scanning Behavior for Predators Can Reduce Rice Damage Caused by Birds

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    Takeshi Honda

    2015-01-01

    Full Text Available Rice is often damaged by birds, especially sparrows, in Asia. Bird nets are sometimes used as countermeasures; however this approach is expensive and labor intensive. For this reason, farmers generally eschew bird nets, even though no alternative countermeasures are available. This study focused on exploiting the bird behavior of scanning for predators to reduce crop damage. When birds forage for seeds on the ground they often stop pecking and briefly raise their heads, apparently to scan for predators. Low visibility habitats increase scanning behavior and increased scanning behavior reduces habitat quality from the bird’s perspective; therefore, this study tested the relationship between rice damage rate and visibility at the periphery of rice fields, where tree sparrows rest after feeding. Overall, low visibility reduced damage to rice. Because visibility was mainly affected by weeds, weed management techniques contribute to crop damage management. To reduce damage, weeding can be decreased; therefore, this technique is cost- and labor-efficient.

  9. Effect of salt on the response of birds to sucrose

    Science.gov (United States)

    Rogers, J.G.; Maller, O.

    1973-01-01

    The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

  10. Magnetoreception and baroreception in birds.

    Science.gov (United States)

    O'Neill, Paul

    2013-01-01

    The world as we know it is defined by our senses, although as humans we are equipped to receive and interpret only a fraction of the potential sensory information available. Birds have evolved with different sensory priorities to our own; they can use the Earth's magnetic field as a navigational aid, and are sensitive to slight changes in barometric pressure. These abilities help explain the impressive ability of many bird species to orientate, navigate, and maintain steady altitude during flight over long distances, even in the absence of clear visual cues. This review will explore the history of research into these "avian" senses, highlighting their likely mechanisms of action, underlying neuronal circuitry and evolutionary origins.

  11. Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B

    2014-01-01

    In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

  12. Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

    Directory of Open Access Journals (Sweden)

    Ana Gabriela Jimenez

    Full Text Available In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR, proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR], using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

  13. Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary

    Science.gov (United States)

    Longrich, Nicholas R.; Tokaryk, Tim; Field, Daniel J.

    2011-01-01

    The effect of the Cretaceous-Paleogene (K-Pg) (formerly Cretaceous–Tertiary, K–T) mass extinction on avian evolution is debated, primarily because of the poor fossil record of Late Cretaceous birds. In particular, it remains unclear whether archaic birds became extinct gradually over the course of the Cretaceous or whether they remained diverse up to the end of the Cretaceous and perished in the K–Pg mass extinction. Here, we describe a diverse avifauna from the latest Maastrichtian of western North America, which provides definitive evidence for the persistence of a range of archaic birds to within 300,000 y of the K–Pg boundary. A total of 17 species are identified, including 7 species of archaic bird, representing Enantiornithes, Ichthyornithes, Hesperornithes, and an Apsaravis-like bird. None of these groups are known to survive into the Paleogene, and their persistence into the latest Maastrichtian therefore provides strong evidence for a mass extinction of archaic birds coinciding with the Chicxulub asteroid impact. Most of the birds described here represent advanced ornithurines, showing that a major radiation of Ornithurae preceded the end of the Cretaceous, but none can be definitively referred to the Neornithes. This avifauna is the most diverse known from the Late Cretaceous, and although size disparity is lower than in modern birds, the assemblage includes both smaller forms and some of the largest volant birds known from the Mesozoic, emphasizing the degree to which avian diversification had proceeded by the end of the age of dinosaurs. PMID:21914849

  14. Cranial kinesis in palaeognathous birds.

    Science.gov (United States)

    Gussekloo, Sander W S; Bout, Ron G

    2005-09-01

    Cranial kinesis in birds is induced by muscles located caudal on the cranium. These forces are transferred onto the moveable parts of the skull via the Pterygoid-Palatinum Complex (PPC). This bony structure therefore plays an essential role in cranial kinesis. In palaeognathous birds the morphology of the PPC is remarkably different from that of neognathous birds and is thought to be related to the specific type of cranial kinesis in palaeognaths known as central rhynchokinesis. We determined whether clear bending zones as found in neognaths are present in the upper bill of paleognaths, and measured bending forces opposing elevation of the upper bill. A static force model was used to calculate the opening forces that can be produced by some of the palaeognathous species. We found that no clear bending zones are present in the upper bill, and bending is expected to occur over the whole length of the upper bill. Muscle forces are more than sufficient to overcome bending forces and to elevate the upper bill. The resistance against bending by the bony elements alone is very low, which might indicate that bending of bony elements can occur during food handling when muscles are not used to stabilise the upper bill. Model calculations suggest that the large processi basipterygoidei play a role in stabilizing the skull elements, when birds have to resist external opening forces on the upper bill as might occur during tearing leafs from plants. We conclude that the specific morphology of the palaeognathous upper bill and PPC are not designed for active cranial kinesis, but are adapted to resist external forces that might cause unwanted elevation of the upper bill during feeding.

  15. Critical Care of Pet Birds.

    Science.gov (United States)

    Jenkins, Jeffrey Rowe

    2016-05-01

    Successful care of the critical pet bird patient is dependent on preparation and planning and begins with the veterinarian and hospital staff. An understanding of avian physiology and pathophysiology is key. Physical preparation of the hospital or clinic includes proper equipment and understanding of the procedures necessary to provide therapeutic and supportive care to the avian patient. An overview of patient intake and assessment, intensive care environment, and fluid therapy is included.

  16. Evolution of oxidation in soybean oil and its biodiesel under the conditions of the oxidation stability test

    Directory of Open Access Journals (Sweden)

    Pereira, G. G.

    2013-12-01

    Full Text Available The objective of this study was to know the evolution of the oxidation of soybean oil and biodiesel under the conditions of the oxidation stability test (110 °C using the Rancimat apparatus. Samples were analyzed at different periods of time until the end of the induction period. The analytical determinations related to the changes in oxidation include peroxide value, anisidine value, natural tocopherols and polar compounds. Acid value, kinematic viscosity, polymers and ester content were also analyzed because of their relevance in the evaluation of biodiesel quality. Results showed that only peroxide value and the group of polar compounds including hydroperoxides, i.e. oxidized monomeric TAG in the oil and oxidized monomeric FAME in the biodiesel increased significantly during the early oxidation stage. The end of the induction period was marked by a rapid increase in polymerization compounds and the exhaustion of tocopherols. Significant changes in acid value, viscosity and ester content were only observed after the end of the induction period.El objetivo de este estudio fue conocer la evolución de la oxidación del aceite de soja y de su biodiesel a 110 °C en las condiciones del método estándar para la determinación de la estabilidad oxidativa, usando el aparato Rancimat. Las muestras se analizaron en diferentes períodos de tiempo hasta que el período de inducción fue sobrepasado. Se determinaron los índices de peróxidos y anisidina, los tocoferoles y los compuestos polares cuyos cambios están relacionados con el desarrollo de la alteración oxidativa. Además, fueron determinados el índice de acidez, la viscosidad y el contenido en ésteres, de interés en el análisis de la calidad del biodiesel. Los resultados indicaron que sólo el índice de peróxidos y el grupo de compuestos polares que incluye los hidroperóxidos (triglicéridos oxidados monómeros en el aceite y ésteres metílicos oxidados monómeros en el biodiesel

  17. Factors influencing phototaxis in nocturnal migrating birds.

    Science.gov (United States)

    Zhao, Xuebing; Chen, Mingyan; Wu, Zhaolu; Wang, Zijiang

    2014-12-01

    Many migratory bird species fly during the night (nocturnal migrants) and have been shown to display some phototaxis to artificial light. During 2006 to 2009, we investigated phototaxis in nocturnal migrants at Jinshan Yakou in Xinping County (N23°56', E101°30'; 2400 m above sea-level), and at the Niaowang Mountain in Funing County (N23°30', E105°35'; 1400 m above sea-level), both in the Yunnan Province of Southwest China. A total of 5069 birds, representing 129 species, were captured by mist-netting and artificial light. The extent of phototaxis effect on bird migration was examined during all four seasons, three phases of the moon, and under two weather conditions (mist and wind). Data were statistically analyzed to determine the extent to which these factors may impact phototaxis of nocturnal migrants. The results point to phototaxis in birds migrating in the spring and autumn, especially in the autumn. Furthermore, migrating birds were more readily attracted to artificial lights during nights with little moonlight, mist, and a headwind. Regardless of the initial orientation in which birds flew, either following the wind or against the wind, birds would always fly against the wind when flying towards the light. This study broadens our understanding of the nocturnal bird migration, potentially resulting in improved bird ringing practices, increased awareness, and better policies regarding bird protection.

  18. Birds and Aircraft on Midway Islands, 1959-63 Investigations

    Science.gov (United States)

    Robbins, C.S.

    1966-01-01

    At Midway Naval Station, 1.100 miles west-northwest of Honolulu, military aircraft collide with flying albatrosses at the rate of about 300 to 400 per year. One aircraft out of every five that hits an albatross on takeoff either aborts (stops before it is airborne), or dumps fuel and returns for appraisal of damage. About 70,000 pairs of Laysan albatrosses and 7,000 pairs of blackfooted albatrosses nest at Midway in any given year. The population is declining. Two-thirds or more of the birds of breeding age nest each year. The minimum breeding age recorded is 5 years (each species), but many individuals do not nest until at least 7 years of age. Young birds begin to return to Midway at 3 years of age and are found more frequently as breeding age approaches. They come ashore more frequently in March and April (the high bird strike months) than in midwinter. Even in midwinter the number of 'walkers' (birds not on nests) may comprise more than 40 percent of the albatrosses present on Sand Island, Midway. Maximum longevity of the Laysan albatross is believed to exceed 40 years; 6 out of 99 birds banded as breeding adults (7+ years old) were still alive 24 years after banding. Control methods tested experimentally include disturbance, gunfire, other sounds, radar beams, smoke, odors, destruction of nests, eggs, chicks, and adults, moving of birds, eggs, and chicks, erection of obstacles to flight, and habitat management. Habitat management (leveling and hardsurfacing of shoulders of runways) has been the most effective. Albatrosses were counted over the runways at 10 locations in 1957, 1958, and 1960 to determine the effects of wind direction, wind speed, and topography on the numbers of flying birds. Birds were most concentrated in areas where rising air currents were created as winds blew against dunes or tall trees. Soaring and strike rate both increased with greater wind speeds. There was a highly significant correlation between strike frequency and wind direction

  19. Serological evidence of continuing high Usutu virus (Flaviviridae) activity and establishment of herd immunity in wild birds in Austria.

    Science.gov (United States)

    Meister, Tanja; Lussy, Helga; Bakonyi, Tamás; Sikutová, Silvie; Rudolf, Ivo; Vogl, Wolfgang; Winkler, Hans; Frey, Hans; Hubálek, Zdenek; Nowotny, Norbert; Weissenböck, Herbert

    2008-03-18

    Usutu virus (USUV), family Flaviviridae, has been responsible for avian mortality in Austria from 2001 to 2006. The proportion of USUV-positive individuals among the investigated dead birds decreased dramatically after 2004. To test the hypothesis that establishment of herd immunity might be responsible, serological examinations of susceptible wild birds were performed. Blood samples of 442 wild birds of 55 species were collected in 4 consecutive years (2003--2006). In addition, 86 individuals from a birds of prey rehabilitation centre were bled before, at the peak, and after the 2005 USUV transmission season in order to identify titre dynamics and seroconversions. The haemagglutination inhibition test was used for screening and the plaque reduction neutralization test for confirmation. While in the years 2003 and 2004 the proportion of seropositive wild birds was 50% in 2005 and 2006. At the birds of prey centre, almost three quarters of the owls and raptors exhibited antibodies before the 2005 transmission season; this percentage dropped to less than half at the peak of USUV transmission and raised again to almost two thirds after the transmission season. These data show a from year to year continuously increasing proportion of seropositive wild birds. The owl and raptor data indicate significant viral exposure in the previous season(s), but also a number of new infections during the current season, despite the presence of antibodies in some of these birds. Herd immunity is a possible explanation for the significant decrease in USUV-associated bird mortalities in Austria during the recent years.

  20. A New "Missing Link" in Dinosaur's Evolution Found

    Institute of Scientific and Technical Information of China (English)

    Song J.; Zhao B.

    2002-01-01

    @@ A group of paleontologists from China, the United States and Canada have made new progress in tracking down the process of the evolution of smallsized dinosaurs and the origin of birds through intensive analysis of the fossils of a newly found dinosaur,Sinovenator, a close relative of birds. In a letter published in the Feb.14 issue of Nature, dinosaur expert Dr. Xu Xing at CAS Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) and his coworkers reveal some interesting phenomena in the process of the evolution of dinosaurs towards birds.

  1. Costs of reproduction can explain the correlated evolution of semelparity and egg size: theory and a test with salmon.

    Science.gov (United States)

    Kindsvater, Holly K; Braun, Douglas C; Otto, Sarah P; Reynolds, John D

    2016-06-01

    Species' life history traits, including maturation age, number of reproductive bouts, offspring size and number, reflect adaptations to diverse biotic and abiotic selection pressures. A striking example of divergent life histories is the evolution of either iteroparity (breeding multiple times) or semelparity (breed once and die). We analysed published data on salmonid fishes and found that semelparous species produce larger eggs, that egg size and number increase with salmonid body size among populations and species and that migratory behaviour and parity interact. We developed three hypotheses that might explain the patterns in our data and evaluated them in a stage-structured modelling framework accounting for different growth and survival scenarios. Our models predict the observation of small eggs in iteroparous species when egg size is costly to maternal survival or egg number is constrained. By exploring trait co-variation in salmonids, we generate new hypotheses for the evolution of trade-offs among life history traits.

  2. Testing Evolution Equation for Entanglement of Two-Qubit Systems in Noisy Channels on Ensemble Quantum Computers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Han; LUO Jun; REN Ting-Ting; SUN Xian-Ping

    2010-01-01

    @@ We report the experimental demonstration of decoherence dynamics of entanglement for the four Bell states in two-qubit nuclear-spin systems on ensemble quantum computers.Using artificial error operators to simulate noisy channels,we experimentally investigate the effect of noises on the four Bell states,and furthermore observe the time evolution of entanglement for the four Bell states in different noisy channels by calculating concurrences.Our experimental results show that the concurrences of the different Bell states under the same artificial error operations have the same values within the experimental error,and are independent of the different Bell states.These experimental results verify the theoretical evolution equation developed by Konrad et al.[Nature Phys.4 (2008) 99]for two-qubit entanglement.

  3. Selective pressures for accurate altruism targeting: evidence from digital evolution for difficult-to-test aspects of inclusive fitness theory.

    Science.gov (United States)

    Clune, Jeff; Goldsby, Heather J; Ofria, Charles; Pennock, Robert T

    2011-03-01

    Inclusive fitness theory predicts that natural selection will favour altruist genes that are more accurate in targeting altruism only to copies of themselves. In this paper, we provide evidence from digital evolution in support of this prediction by competing multiple altruist-targeting mechanisms that vary in their accuracy in determining whether a potential target for altruism carries a copy of the altruist gene. We compete altruism-targeting mechanisms based on (i) kinship (kin targeting), (ii) genetic similarity at a level greater than that expected of kin (similarity targeting), and (iii) perfect knowledge of the presence of an altruist gene (green beard targeting). Natural selection always favoured the most accurate targeting mechanism available. Our investigations also revealed that evolution did not increase the altruism level when all green beard altruists used the same phenotypic marker. The green beard altruism levels stably increased only when mutations that changed the altruism level also changed the marker (e.g. beard colour), such that beard colour reliably indicated the altruism level. For kin- and similarity-targeting mechanisms, we found that evolution was able to stably adjust altruism levels. Our results confirm that natural selection favours altruist genes that are increasingly accurate in targeting altruism to only their copies. Our work also emphasizes that the concept of targeting accuracy must include both the presence of an altruist gene and the level of altruism it produces.

  4. Deep global evolutionary radiation in birds: diversification and trait evolution in the cosmopolitan bird family Rallidae.

    Science.gov (United States)

    Garcia-R, Juan C; Gibb, Gillian C; Trewick, Steve A

    2014-12-01

    Sufficient breadth of taxon sampling in major organisms groups is important to identify more realistic biological diversification processes that reveal the degree of historical biogeographic signal and net diversification retained in the current lineage distribution. We examine the mechanisms driving diversity in one of the major avian clades with an exceptional large-scale radiation, the family Rallidae, using the most complete species-level (∼70%) time calibrated hypothesis of evolutionary relationships produced to date. We find that Rallidae exhibit a pattern of diversification involving episodes of range expansion and regional speciation that results in most clades represented in all habitable continents. Our results suggest that several features may have played an important role on the diversification rates in Rallidae. Lineage accumulation is nearly constant and morphology (frontal shield and body size), innovate (flightlessness), habitat (forest) and distribution (insular) traits are possibly associated with increasing diversification rates along with spatial and ecological processes during the Miocene and Pliocene. Diversification and the global retention of lineage diversity have occurred in multiple lineages in Rallidae due to their dispersal ability and exploitation of ecological opportunities.

  5. Magnetoreception in birds: II. Behavioural experiments concerning the cryptochrome cycle.

    Science.gov (United States)

    Wiltschko, Roswitha; Gehring, Dennis; Denzau, Susanne; Nießner, Christine; Wiltschko, Wolfgang

    2014-12-01

    Behavioural tests of the magnetic compass of birds and corresponding immunohistological studies on the activation of retinal cryptochrome 1a, the putative receptor molecule, showed oriented behaviour and activated Cry1a under 373 nm UV, 424 nm blue, 502 nm turquoise and 565 nm green light, although the last wavelength does not allow the first step of photoreduction of cryptochrome to the semiquinone form. The tested birds had been kept under 'white' light before, hence we suggested that there was a supply of semiquinone present at the beginning of the exposure to green light that could be further reduced and then re-oxidized. To test the hypothesis in behavioural experiments, we tested robins, Erithacus rubecula, under various wavelengths (1) after 1 h pre-exposure to total darkness and (2) after 1 h pre-exposure to the same light as used in the test. The birds were oriented under blue and turquoise light, where the full cryptochrome cycle can run, but not under green light. This finding is in agreement with the hypothesis. Orientation under green light appears to be a transient phenomenon until the supply of semiquinone is depleted.

  6. Bat predation on nocturnally migrating birds.

    Science.gov (United States)

    Ibáñez, C; Juste, J; García-Mudarra, J L; Agirre-Mendi, P T

    2001-08-14

    Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the world's temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures and eats large numbers of migrating passerines, making it the only bat species so far known that regularly preys on birds. The echolocation characteristics and wing morphology of this species strongly suggest that it captures birds in flight.

  7. Differences in predatory pressure on terrestrial snails by birds and mammals

    Indian Academy of Sciences (India)

    Zuzanna M Rosin; Paulina Olborska; Adrian Surmacki; Piotr Tryjanowski

    2011-09-01

    The evolution of shell polymorphism in terrestrial snails is a classic textbook example of the effect of natural selection in which avian and mammalian predation represents an important selective force on gene frequency. However, many questions about predation remain unclear, especially in the case of mammals. We collected 2000 specimens from eight terrestrial gastropod species to investigate the predation pressure exerted by birds and mice on snails. We found evidence of avian and mammalian predation in 26.5% and 36.8% of the shells. Both birds and mammals were selective with respect to snail species, size and morphs. Birds preferred the brown-lipped banded snail Cepaea nemoralis (L.) and mice preferred the burgundy snail Helix pomatia L. Mice avoided pink mid-banded C. nemoralis and preferred brown mid-banded morphs, which were neglected by birds. In contrast to mice, birds chose larger individuals. Significant differences in their predatory pressure can influence the evolution and maintenance of shell size and polymorphism of shell colouration in snails.

  8. Wild birds as sentinels for multiple zoonotic pathogens along an urban to rural gradient in greater Chicago, Illinois.

    Science.gov (United States)

    Hamer, S A; Lehrer, E; Magle, S B

    2012-08-01

    Wild birds are important in the maintenance and transmission of many zoonotic pathogens. With increasing urbanization and the resulting emergence of zoonotic diseases, it is critical to understand the relationships among birds, vectors, zoonotic pathogens, and the urban landscape. Here, we use wild birds as sentinels across a gradient of urbanization to understand the relative risk of diseases caused by three types of zoonotic pathogens: Salmonella pathogens, mosquito-borne West Nile virus (WNV) and tick-borne pathogens, including the agents of Lyme disease and human anaplasmosis. Wild birds were captured using mist nets at five sites throughout greater Chicago, Illinois, and blood, faecal and ectoparasite samples were collected for diagnostic testing. A total of 289 birds were captured across all sites. A total of 2.8% of birds harboured Ixodes scapularis--the blacklegged tick--of which 54.5% were infected with the agent of Lyme disease, and none were infected with the agent of human anaplasmosis. All infested birds were from a single site that was relatively less urban. A single bird, captured at the only field site in which supplemental bird feeding was practised within the mist netting zone, was infected with Salmonella enterica subspecies enterica. While no birds harboured WNV in their blood, 3.5% of birds were seropositive, and birds from more urban sites had higher exposure to the virus than those from less urban sites. Our results demonstrate the presence of multiple bird-borne zoonotic pathogens across a gradient of urbanization and provide an assessment of potential public health risks to the high-density human populations within the area.

  9. Survey of birds and lizards for ixodid ticks (Acari) and spirochetal infection in northern California.

    Science.gov (United States)

    Manweiler, S A; Lane, R S; Block, W M; Morrison, M L

    1990-11-01

    A total of 138 birds (24 species) was captured in an oak woodland between December 1988 and June 1989 at the University of California, Sierra Foothill Range Field Station, Yuba County, Calif. Ticks were not found on 71 birds captured between December 1988 and March 1989. Five subadult Ixodes pacificus Cooley & Kohls were removed from 3 of 67 birds caught between April and June 1989. These three birds, an orange-crowned warbler (Vermivora celata (Say], a lazuli bunting (Passerina amoena (Say], and a chipping sparrow (Spizella passerina (Bechstein], represent new host records for I. pacificus in California. Tissues from two ticks and thick blood films prepared from 126 birds tested negative for spirochetes by direct immunofluorescence (DI). A total of 172 larval and 197 nymphal I. pacificus was removed from 15 of 16 western fence lizards (Sceloporus occidentalis Baird & Girard) caught between April and June 1989 in the same location as were birds. Thick blood films prepared from all 16 lizards and tissue smears from 334 of the ticks (143 larvae and 191 nymphs) were DI test-negative for spirochetes. One (1.1%) of 93 adult I. pacificus collected at the bird-lizard capture site in February 1989 was infected with spirochetes that resembled B. burgdorferi.

  10. The winter bird survey of central Maryland, U.S.A

    Science.gov (United States)

    Robbins, C.S.; Bystrak, D.

    1974-01-01

    A method for monitoring changes in winter bird populations was tested in central Maryland in the winters of 1970, 1971 and 1972. A systematic sample of 41 transects was established to sample an area of 6150 sq. km. Each transect, located at the center of a standard 7 1/2-minute topographic map, was 8 km in length and approximately square in shape. Coverage began at local sunrise on any one day from 15 January to 15 February, and was completed in exactly 4 hours. Birds seen or heard within one-fourth mile (0.40) km were recorded separately for each hour, and those identified at a greater distance were entered in a separate column. The mean number of species per route was 29. Ten species showed a statistically significant change from 1970 to 1971 and 8 from 1971 to 1972. The Winter Bird Survey results were compared with the results from the Audubon Society's Christmas Bird Count in the same area. Close correlation was found between the two surveys, but in general the Winter Bird Survey totals are higher except for species that frequent feeding trays and those that are conspicuous along roadsides. The Winter Bird Survey method shows much promise as a means of world-wide monitoring of bird populations; it is urged that field tests be conducted on other continents.

  11. Personality matters: individual variation in reactions of naive bird predators to aposematic prey.

    Science.gov (United States)

    Exnerová, Alice; Svádová, Katerina Hotová; Fucíková, Eva; Drent, Pieter; Stys, Pavel

    2010-03-01

    Variation in reactions to aposematic prey is common among conspecific individuals of bird predators. It may result from different individual experience but it also exists among naive birds. This variation may possibly be explained by the effect of personality--a complex of correlated, heritable behavioural traits consistent across contexts. In the great tit (Parus major), two extreme personality types have been defined. 'Fast' explorers are bold, aggressive and routine-forming; 'slow' explorers are shy, non-aggressive and innovative. Influence of personality type on unlearned reaction to aposematic prey, rate of avoidance learning and memory were tested in naive, hand-reared great tits from two opposite lines selected for exploration (slow against fast). The birds were subjected to a sequence of trials in which they were offered aposematic adult firebugs (Pyrrhocoris apterus). Slow birds showed a greater degree of unlearned wariness and learned to avoid the firebugs faster than fast birds. Although birds of both personality types remembered their experience, slow birds were more cautious in the memory test. We conclude that not only different species but also populations of predators that differ in proportions of personality types may have different impacts on survival of aposematic insects under natural conditions.

  12. Should Australia Export its Native Birds?

    OpenAIRE

    Kingwell, Ross S.

    1994-01-01

    Commercial export from Australia of native birds, wild or captive bred, is prohibited. This paper firstly describes the current legislation and regulations that restrict the export of native birds and discusses why governments have adopted such a regulatory approach to bird species preservation. Secondly, the paper reviews the debate concerning the export ban, pointing out strengths and weaknesses in arguments and indicating the important role of CITES. Lastly, the paper outlines a new case f...

  13. A checklist of birds of Kerala, India

    Directory of Open Access Journals (Sweden)

    Praveen J

    2015-11-01

    Full Text Available A checklist of birds of Kerala State is presented in this paper.  Accepted English names, scientific binomen, prevalent vernacular names in Malayalam, IUCN conservation status, endemism, Wildlife (Protection Act schedules, and the appendices in the CITES, pertaining to the birds of Kerala are also given.  The State of Kerala has 500 species of birds, 17 of which are endemic to Western Ghats, and 24 species fall under the various threatened categories of IUCN. 

  14. Rice production systems and avian influenza: Interactions between mixed-farming systems, poultry and wild birds

    Science.gov (United States)

    Muzaffar, S.B.; Takekawa, J.Y.; Prosser, D.J.; Newman, S.H.; Xiao, X.

    2010-01-01

    Wild waterfowl are the reservoir for avian influenza viruses (AIVs), a family of RNA viruses that may cause mild sickness in waterbirds. Emergence of H5N1, a highly pathogenic avian influenza (HPAI) strain, causing severe disease and mortality in wild birds, poultry and humans, had raised concerns about the role of wild birds in possible transmission of the disease. In this review, the link between rice production systems, poultry production systems, and wild bird ecology is examined to assess the extent to which these interactions could contribute towards the persistence and evolution of HPAI H5N1. The rice (Oryza sativa) and poultry production systems in Asia described, and then migration and movements of wild birds discussed. Mixed farming systems in Asia and wild bird movement and migration patterns create opportunities for the persistence of low pathogenic AIVs in these systems. Nonetheless, there is no evidence of long-term persistence of HPAI viruses (including the H5N1 subtype) in the wild. There are still significant gaps in the understanding of how AIVs circulate in rice systems. A better understanding of persistence of AIVs in rice farms, particularly of poultry origins, is essential in limiting exchange of AIVs between mixed-farming systems, poultry and wild birds.

  15. Effects of Grassland Bird Management on Nongame Bird Community Structure and Productivity

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The report includes data on bird/habitat relations, breeding biology, and effects of succession and current management practices on grassland bird communities in the...

  16. Aleutian Islands Coastal Resources Inventory and Environmental Sensitivity Maps: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in the Aleutian Islands, Alaska....

  17. Grassland bird surveys in support of the Michigan Breeding Bird Atlas II: Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Grassland birds, as a group, have suffered the most severe population declines of any other North American birds (Herkert 1995, Herkert et al. 1996). Compared to...

  18. How hollow melanosomes affect iridescent colour production in birds.

    Science.gov (United States)

    Eliason, Chad M; Bitton, Pierre-Paul; Shawkey, Matthew D

    2013-09-22

    Developmental constraints and trade-offs can limit diversity, but organisms have repeatedly evolved morphological innovations that overcome these limits by expanding the range and functionality of traits. Iridescent colours in birds are commonly produced by melanin-containing organelles (melanosomes) organized into nanostructured arrays within feather barbules. Variation in array type (e.g. multilayers and photonic crystals, PCs) is known to have remarkable effects on plumage colour, but the optical consequences of variation in melanosome shape remain poorly understood. Here, we used a combination of spectrophotometric, experimental and theoretical methods to test how melanosome hollowness--a morphological innovation largely restricted to birds--affects feather colour. Optical analyses of hexagonal close-packed arrays of hollow melanosomes in two species, wild turkeys (Meleagris gallopavo) and violet-backed starlings (Cinnyricinclus leucogaster), indicated that they function as two-dimensional PCs. Incorporation of a larger dataset and optical modelling showed that, compared with solid melanosomes, hollow melanosomes allow birds to produce distinct colours with the same energetically favourable, close-packed configurations. These data suggest that a morphological novelty has, at least in part, allowed birds to achieve their vast morphological and colour diversity.

  19. Tuberculosis in Birds: Insights into the Mycobacterium avium Infections

    Directory of Open Access Journals (Sweden)

    Kuldeep Dhama

    2011-01-01

    Full Text Available Tuberculosis, a List B disease of World Organization for Animal Health, caused by M. avium or M. genavense predominantly affects poultry and pet or captive birds. Clinical manifestations in birds include emaciation, depression and diarrhea along with marked atrophy of breast muscle. Unlike tuberculosis in animals and man, lesions in lungs are rare. Tubercular nodules can be seen in liver, spleen, intestine and bone marrow. Granulomatous lesion without calcification is a prominent feature. The disease is a rarity in organized poultry sector due to improved farm practices, but occurs in zoo aviaries. Molecular techniques like polymerase chain reaction combined with restriction fragment length polymorphism and gene probes aid in rapid identification and characterization of mycobacteria subspecies, and overcome disadvantages of conventional methods which are slow, labour intensive and may at times fail to produce precise results. M. avium subsp. avium with genotype IS901+ and IS1245+ causes infections in animals and human beings too. The bacterium causes sensitivity in cattle to the tuberculin test. The paper discusses in brief the M. avium infection in birds, its importance in a zoonotic perspective, and outlines conventional and novel strategies for its diagnosis, prevention and eradication in domestic/pet birds and humans alike.

  20. Magnetoreception in birds: the effect of radio-frequency fields.

    Science.gov (United States)

    Wiltschko, Roswitha; Thalau, Peter; Gehring, Dennis; Nießner, Christine; Ritz, Thorsten; Wiltschko, Wolfgang

    2015-02-01

    The avian magnetic compass, probably based on radical pair processes, works only in a narrow functional window around the local field strength, with cryptochrome 1a as most likely receptor molecule. Radio-frequency fields in the MHz range have been shown to disrupt the birds' orientation, yet the nature of this interference is still unclear. In an immuno-histological study, we tested whether the radio-frequency fields interfere with the photoreduction of cryptochrome, but this does not seem to be the case. In behavioural studies, birds were not able to adjust to radio-frequency fields like they are able to adjust to static fields outside the normal functional range: neither a 2-h pre-exposure in a 7.0 MHz field, 480 nT, nor a 7-h pre-exposure in a 1.315 MHz field, 15 nT, allowed the birds to regain their orientation ability. This inability to adjust to radio-frequency fields suggests that these fields interfere directly with the primary processes of magnetoreception and therefore disable the avian compass as long as they are present. They do not have lasting adverse after-effects, however, as birds immediately after exposure to a radio-frequency field were able to orient in the local geomagnetic field.

  1. LiteBIRD: mission overview and design tradeoffs

    Science.gov (United States)

    Matsumura, T.; Akiba, Y.; Borrill, J.; Chinone, Y.; Dobbs, M.; Fuke, H.; Hasegawa, M.; Hattori, K.; Hattori, M.; Hazumi, M.; Holzapfel, W.; Hori, Y.; Inatani, J.; Inoue, M.; Inoue, Y.; Ishidoshiro, K.; Ishino, H.; Ishitsuka, H.; Karatsu, K.; Kashima, S.; Katayama, N.; Kawano, I.; Kibayashi, A.; Kibe, Y.; Kimura, K.; Kimura, N.; Komatsu, E.; Kozu, M.; Koga, K.; Lee, A.; Matsuhara, H.; Mima, S.; Mitsuda, K.; Mizukami, K.; Morii, H.; Morishima, T.; Nagai, M.; Nagata, R.; Nakamura, S.; Naruse, M.; Namikawa, T.; Natsume, K.; Nishibori, T.; Nishijo, K.; Nishino, H.; Noda, A.; Noguchi, T.; Ogawa, H.; Oguri, S.; Ohta, I. S.; Okada, N.; Otani, C.; Richards, P.; Sakai, S.; Sato, N.; Sato, Y.; Segawa, Y.; Sekimoto, Y.; Shinozaki, K.; Sugita, H.; Suzuki, A.; Suzuki, T.; Tajima, O.; Takada, S.; Takakura, S.; Takei, Y.; Tomaru, T.; Uzawa, Y.; Wada, T.; Watanabe, H.; Yamada, Y.; Yamaguchi, H.; Yamasaki, N.; Yoshida, M.; Yoshida, T.; Yotsumoto, K.

    2014-08-01

    We present the mission design of LiteBIRD, a next generation satellite for the study of B-mode polarization and inflation from cosmic microwave background radiation (CMB) detection. The science goal of LiteBIRD is to measure the CMB polarization with the sensitivity of δr = 0:001, and this allows testing the major single-field slow-roll inflation models experimentally. The LiteBIRD instrumental design is purely driven to achieve this goal. At the earlier stage of the mission design, several key instrumental specifications, e.g. observing band, optical system, scan strategy, and orbit, need to be defined in order to process the rest of the detailed design. We have gone through the feasibility studies for these items in order to understand the tradeoffs between the requirements from the science goal and the compatibilities with a satellite bus system. We describe the overview of LiteBIRD and discuss the tradeoffs among the choices of scientific instrumental specifications and strategies. The first round of feasibility studies will be completed by the end of year 2014 to be ready for the mission definition review and the target launch date is in early 2020s.

  2. Differences in muscle fiber size and associated energetic costs in phylogenetically paired tropical and temperate birds.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Williams, Joseph B

    2014-01-01

    Tropical and temperate birds provide a unique system to examine mechanistic consequences of life-history trade-offs at opposing ends of the pace-of-life spectrum; tropical birds tend to have a slow pace of life whereas temperate birds the opposite. Birds in the tropics have a lower whole-animal basal metabolic rate and peak metabolic rate, lower rates of reproduction, and longer survival than birds in temperate regions. Although skeletal muscle has a relatively low tissue-specific metabolism at rest, it makes up the largest fraction of body mass and therefore contributes more to basal metabolism than any other tissue. A principal property of muscle cells that influences their rate of metabolism is fiber size. The optimal fiber size hypothesis attempts to link whole-animal basal metabolic rate to the cost of maintaining muscle mass by stating that larger fibers may be metabolically cheaper to maintain since the surface area∶volume ratio (SA∶V) is reduced compared with smaller fibers and thus the amount of area to transport ions is also reduced. Because tropical birds have a reduced whole-organism metabolism, we hypothesized that they would have larger muscle fibers than temperate birds, given that larger muscle fibers have reduced energy demand from membrane Na(+)-K(+) pumps. Alternatively, smaller muscle fibers could result in a lower capacity for shivering and exercise. To test this idea, we examined muscle fiber size and Na(+)-K(+)-ATPase activity in 16 phylogenetically paired species of tropical and temperate birds. We found that 3 of the 16 paired comparisons indicated that tropical birds had significantly larger fibers, contrary to our hypothesis. Our data show that SA∶V is proportional to Na(+)-K(+)-ATPase activity in muscles of birds.

  3. Ecological Sustainability of Birds in Boreal Forests

    Directory of Open Access Journals (Sweden)

    Gerald Niemi

    1998-12-01

    Full Text Available We review characteristics of birds in boreal forests in the context of their ecological sustainability under both natural and anthropogenic disturbances. We identify the underlying ecological factors associated with boreal bird populations and their variability, review the interactions between boreal bird populations and disturbance, and describe some tools on how boreal bird populations may be conserved in the future. The boreal system has historically been an area with extensive disturbance such as fire, insect outbreaks, and wind. In addition, the boreal system is vulnerable to global climate change as well as increasing pressure on forest and water resources. Current knowledge indicates that birds play an important role in boreal forests, and sustaining these populations affords many benefits to the health of boreal forests. Many issues must be approached with caution, including the lack of knowledge on our ability to mimic natural disturbance regimes with management, our lack of understanding on fragmentation due to logging activity, which is different from permanent conversion to other land uses such as agriculture or residential area, and our lack of knowledge on what controls variability in boreal bird populations or the linkage between bird population fluctuations and productivity. The essential role that birds can provide is to clarify important ecological concerns and variables that not only will help to sustain bird populations, but also will contribute to the long-term health of the boreal forest for all species, including humans.

  4. Bird sexing by Fourier transform infrared spectroscopy

    Science.gov (United States)

    Steiner, Gerald; Bartels, Thomas; Krautwald-Junghanns, Maria-Elisabeth; Koch, Edmund

    2010-02-01

    Birds are traditionally classified as male or female based on their anatomy and plumage color as judged by the human eye. Knowledge of a bird's gender is important for the veterinary practitioner, the owner and the breeder. The accurate gender determination is essential for proper pairing of birds, and knowing the gender of a bird will allow the veterinarian to rule in or out gender-specific diseases. Several biochemical methods of gender determination have been developed for avian species where otherwise the gender of the birds cannot be determined by their physical appearances or characteristics. In this contribution, we demonstrate that FT-IR spectroscopy is a suitable tool for a quick and objective determination of the bird's gender. The method is based on differences in chromosome size. Male birds have two Z chromosomes and female birds have a W-chromosome and a Z-chromosome. Each Z-chromosome has approx. 75.000.000 bps whereas the W-chromosome has approx. 260.00 bps. This difference can be detected by FT-IR spectroscopy. Spectra were recorded from germ cells obtained from the feather pulp of chicks as well as from the germinal disk of fertilized but non-bred eggs. Significant changes between cells of male and female birds occur in the region of phosphate vibrations around 1080 and 1120 cm-1.

  5. Capturing birds with mist nets: A review

    Science.gov (United States)

    Keyes, B.E.; Grue, C.E.

    1982-01-01

    Herein we have tried to provide a comprehensive review of mist-netting techniques suitable for both novice and experienced netters. General mist-netting procedures and modifications developed by netters for particular bird species and habitats are included. Factors which influence capture success, including site selection, net specifications and placement, weather, and time of day, are discussed. Guidelines are presented for the care of netted birds and the use of mist-net data in the study of bird communities. The advantages of the use of mist nets over other methods of capturing birds are also discussed.

  6. Birds and bird habitats: guidelines for wind power projects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Established in 2009, the Green Energy Act aims to increase the use of renewable energy sources including wind, water, solar and bioenergy in Ontario. The development of these resources is a major component of the province's plan, which aims to mitigate the contribution to climate change and to involve the Ontario's economy in the improvement of the quality of the environment. The Green Energy Act also considers as important the implementation of a coordinated provincial approval process, suggesting the integration of all Ministry requirements into a unique process during the evaluation of newly proposed renewable energy projects. The Ministry of the Environment's Renewable Energy Approval Regulation details the requirements for wind power projects involving significant natural features. Birds are an important part of Ontario's biodiversity and, according to the Ministry of Natural Resources, their habitats are considered as significant wildlife habitat (SWH). The Renewable Energy Approval Regulation and this guideline are meant to provide elements and guidance in order to protect bird SWH during the selection of a location of wind power facilities. . 27 refs., 1 tab., 2 figs.

  7. Can uncertain landscape evolution models discriminate between landscape responses to stable and changing future climate? A millennial-scale test

    Science.gov (United States)

    Temme, A. J. A. M.; Baartman, J. E. M.; Schoorl, J. M.

    2009-10-01

    In the light of increasing societal interest in the effects of climate change, geomorphologists face the task of discriminating between natural landscape changes and landscape changes that result from human-induced climate change. Landscape Evolution Models (LEMs) are available for this purpose, but their application for prediction of future landscapes is problematic. Calibration of LEMs on a sufficiently long palaeo-record of landscape change solves some of these problems, but large uncertainties in input (e.g. climate) records and process descriptions remain. Using one of the few existing ka-scale LEM studies as starting point, this paper explores how uncertainty in the LEM LAPSUS (LandscApe ProcesS modelling at mUlti dimensions and scaleS, [Schoorl, J.M., Veldkamp, A. and Bouma, J., 2002. Modeling water and soil redistribution in a dynamic landscape context. Soil Science Society of America Journal, 66(5): 1610-1619]) affects its ability to discriminate future one-thousand year landscape change under stable climate from that under human-induced changed climate. Okhombe Valley in South Africa is used as a case study area. LEM uncertainty is characterized by different levels of parameter uncertainty. Results indicate that even under high levels of parameter uncertainty, LEM LAPSUS discriminates between responses to stable and changed climates for some zones in the landscape. Although confidence in model predictions remains limited, some explorative and relative conclusions about the effects of changed climate on future landscape evolution of Okhombe Valley are drawn. Finally, some possibilities and limitations of future studies on landscape evolution under changing climate are discussed.

  8. The role of indigenous wild, semidomestic, and exotic birds in the epizootiology of velogenic viscerotropic Newcastle disease in southern California, 1972-1973

    Science.gov (United States)

    Pearson, G.L.; McCann, M.K.

    1975-01-01

    During an epornitic of velogenic viscerotropic Newcastle disease (VVND) in southern California, free-flying wild birds, captive and free-ranging semidomestic birds, and exotic birds were collected from the quarantine area to determine their role in the epizootiology of the disease. The VVND virus was isolated from 0.04% of 9,446 free-flying wild birds, 0.76% of 4,367 semidomestic birds, and 1.01% of 3,780 exotic birds examined. Three house sparrows and 1 crow directly associated with infected poultry flocks were the only free-flying wild birds from which VVND virus was isolated. Among semidomestic species, ducks, quail, chukars, pheasants, peafowl, pigeons, and doves were found to be infected. Psittacines, pittas, and toucans accounted for 92% of the VVND virus isolations from exotic birds. In addition, domestic Newcastle disease virus (NDV) was isolated from 0.29% of the free-flying wild birds, from 1.65% of the semidomestic birds, and from 0.19% of the exotic birds collected. Hemagglutination-inhibition against domestic NDV was demonstrated in 0.24% of 3,796 wild bird serums, 8.28% of 2,004 semidomestic bird serums, and 3.90% of 231 exotic bird serums tested.Although few free-flying wild birds were infected with VVND virus in this epornitic, the isolation of domestic NDV strains from free-flying wild ducks and mourning doves suggests the potential for transportation of NDV over long distances by migratory birds.

  9. Junius B. Bird (1907- 1982)

    OpenAIRE

    Morris, Craig

    2014-01-01

    El 2 de abril de 1982 la arqueología andina perdió a uno de sus más distinguidos y queridos arqueólogos. Junius Bouton Bird falleció en la ciudad de Nueva York a la edad de 74 años, luego de una breve batalla con el cáncer. Era Conservador Emérito de Arqueología de Sud América en el Museo Americano de Historia Natural, su residencia científica durante la mayor parte de sus 50 años de vida profesional.

  10. Rickettsial infections in ticks from reptiles, birds and humans in Honduras.

    Science.gov (United States)

    Novakova, Marketa; Literak, Ivan; Chevez, Luis; Martins, Thiago F; Ogrzewalska, Maria; Labruna, Marcelo B

    2015-09-01

    Ticks were collected from captive reptiles, wild birds, and incidentally from humans at two locations in Honduras and part of these were tested for the presence of Rickettsia using polymerase chain reaction. The following species of ticks were found: Amblyomma dissimile on Iguanidae reptiles, Amblyomma longirostre and Amblyomma nodosum on birds, and Amblyomma mixtum (Amblyomma cajennense complex) on humans. A. dissimile was infected with Rickettsia sp. strain Colombianensi. Both A. longirostre and A. mixtum were infected with Candidatus 'Rickettsia amblyommii'. This study provides the first report of rickettsial infections in ticks from reptiles, birds and humans in Honduras. New host - Amblyomma tick associations are documented.

  11. Cold- and exercise-induced peak metabolic rates in tropical birds

    OpenAIRE

    Wiersma, Popko; Chappell, Mark A; Williams, Joseph B.

    2007-01-01

    Compared with temperate birds, tropical birds have low reproductive rates, slow development as nestlings, and long lifespans. These “slow” life history traits are thought to be associated with reduced energy expenditure, or a slow “pace of life.” To test predictions from this hypothesis, we measured exercise-induced peak metabolic rates (PMRE) in 45 species of tropical lowland forest birds and compared these data with PMRE for three temperate species. We also compared cold-induced PMR (PMRC) ...

  12. Birds shed RNA-viruses according to the pareto principle.

    Directory of Open Access Journals (Sweden)

    Mark D Jankowski

    Full Text Available A major challenge in disease ecology is to understand the role of individual variation of infection load on disease transmission dynamics and how this influences the evolution of resistance or tolerance mechanisms. Such information will improve our capacity to understand, predict, and mitigate pathogen-associated disease in all organisms. In many host-pathogen systems, particularly macroparasites and sexually transmitted diseases, it has been found that approximately 20% of the population is responsible for approximately 80% of the transmission events. Although host contact rates can account for some of this pattern, pathogen transmission dynamics also depend upon host infectiousness, an area that has received relatively little attention. Therefore, we conducted a meta-analysis of pathogen shedding rates of 24 host (avian - pathogen (RNA-virus studies, including 17 bird species and five important zoonotic viruses. We determined that viral count data followed the Weibull distribution, the mean Gini coefficient (an index of inequality was 0.687 (0.036 SEM, and that 22.0% (0.90 SEM of the birds shed 80% of the virus across all studies, suggesting an adherence of viral shedding counts to the Pareto Principle. The relative position of a bird in a distribution of viral counts was affected by factors extrinsic to the host, such as exposure to corticosterone and to a lesser extent reduced food availability, but not to intrinsic host factors including age, sex, and migratory status. These data provide a quantitative view of heterogeneous virus shedding in birds that may be used to better parameterize epidemiological models and understand transmission dynamics.

  13. Birds shed RNA-viruses according to the pareto principle.

    Science.gov (United States)

    Jankowski, Mark D; Williams, Christopher J; Fair, Jeanne M; Owen, Jennifer C

    2013-01-01

    A major challenge in disease ecology is to understand the role of individual variation of infection load on disease transmission dynamics and how this influences the evolution of resistance or tolerance mechanisms. Such information will improve our capacity to understand, predict, and mitigate pathogen-associated disease in all organisms. In many host-pathogen systems, particularly macroparasites and sexually transmitted diseases, it has been found that approximately 20% of the population is responsible for approximately 80% of the transmission events. Although host contact rates can account for some of this pattern, pathogen transmission dynamics also depend upon host infectiousness, an area that has received relatively little attention. Therefore, we conducted a meta-analysis of pathogen shedding rates of 24 host (avian) - pathogen (RNA-virus) studies, including 17 bird species and five important zoonotic viruses. We determined that viral count data followed the Weibull distribution, the mean Gini coefficient (an index of inequality) was 0.687 (0.036 SEM), and that 22.0% (0.90 SEM) of the birds shed 80% of the virus across all studies, suggesting an adherence of viral shedding counts to the Pareto Principle. The relative position of a bird in a distribution of viral counts was affected by factors extrinsic to the host, such as exposure to corticosterone and to a lesser extent reduced food availability, but not to intrinsic host factors including age, sex, and migratory status. These data provide a quantitative view of heterogeneous virus shedding in birds that may be used to better parameterize epidemiological models and understand transmission dynamics.

  14. Ecological and evolutionary physiology of desert birds: a progress report.

    Science.gov (United States)

    Williams, Joseph B; Tieleman, B Irene

    2002-02-01

    The adaptive significance of mechanisms of energy and water conservation among species of desert rodents, which avoid temperature extremes by remaining within a burrow during the day, is well established. Conventional wisdom holds that arid-zone birds, diurnal organisms that endure the brunt of their environment, occupy these desert climates because of the possession of physiological design features common to all within the class Aves. We review studies that show that desert birds may have evolved specific features to deal with hot desert conditions including: a reduced basal metabolic rate (BMR) and field metabolic rate (FMR), and lower total evaporative water loss (TEWL) and water turnover (WTO).Previous work on the comparative physiology of desert birds relied primarily on information gathered on species from the deserts of the southwestern U.S., which are semi-arid habitats of recent geologic origin. We include data on species from Old World deserts, which are geologically older than those in the New World, and place physiological responses along an aridity axis that includes mesic, semi-arid, arid, and hyperarid environments.The physiological differences between desert and mesic birds that we have identified using the comparative method could arise as a result of acclimation to different environments, of genetic change mediated by selection, or both. We present data on the flexibility of BMR and TEWL in Hoopoe Larks that suggest that phenotypic adjustments in these variables can be substantial. Finally, we suggest that linkages between the physiology of individual organism and its life-history are fundamental to the understanding of life-history evolution.

  15. Comparing the co-evolution of production and test code in open source and industrial developer test processes through repository mining

    NARCIS (Netherlands)

    Van Rompaey, B.; Zaidman, A.E.; Van Deursen, A.; Demeyer, S.

    2008-01-01

    This paper represents an extension to our previous work: Mining software repositories to study coevolution of production & test code. Proceedings of the International Conference on Software Testing, Verification, and Validation (ICST), IEEE Computer Society, 2008; doi:10.1109/ICST.2008.47 Engineeri

  16. Care, food consumption, and behavior of bald eagles used in DDT tests

    Science.gov (United States)

    Chura, N.J.; Stewart, P.A.

    1967-01-01

    Twenty-seven Bald Eagles captured in southeastern Alaska were used in feeding tests to determine the effects of DDT in the diet.....Trapping and housing of eagles are discussed. Various aspects of eagle behavior and handling techniques are also presented. Recommendations are made for preventing injuries and increasing the comfort of captive birds.....The 1962 test birds consumed an average of 274 grams per bird day with a range of 109 to 401 grams per day between birds. Average food intake was 254 grams per bird day for the 1963 test birds with a range of 194 to 324 grams per day between birds.....Weight losses varied from 23 to 49 per cent of normal body weight for the 7 birds which died in the 1962 tests. Tremors and death occurred first for birds on the highest dosage and progressively later for birds on the lower dosages.

  17. Exchange of Newcastle disease viruses in Korea: the relatedness of isolates between wild birds, live bird markets, poultry farms and neighboring countries.

    Science.gov (United States)

    Kim, Byoung-Yoon; Lee, Dong-Hun; Kim, Myeong-Seob; Jang, Jun-Hyuk; Lee, Yu-Na; Park, Jae-Keun; Yuk, Seong-Su; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

    2012-03-01

    Newcastle disease virus (NDV) has a worldwide distribution and is often carried by wild ducks, which may represent one of the natural reservoirs. However, the epidemiological relatedness of NDV between wild ducks and domestic poultry is unclear. A total of 14 isolates were obtained from 8439 samples from live bird markets (LBMs) and wild bird populations in Korea during from 2007 to 2010. These isolates were characterized genetically and phylogenetic analysis was conducted to investigate the relatedness between isolates from wild birds, LBM and poultry farms. In phylogenetic analysis, all 14 isolates belonged to genotype I virus within class II. Of these, nine isolates from wild birds were most closely related to the Aomori-like cluster. The five LBM isolates were most closely related to the V4-like cluster. All isolates in this study were closely related to isolates from domestic duck farms in Korea and Chinese LBM isolates. The results indicate that NDV exchange occurs between wild birds, poultry farms, LBMs and neighboring countries. Enhanced NDV surveillance is required to monitor the introduction of variant NDV in consequence of evolution in LBMs and to investigate NDV epidemiology in various species of putative hosts.

  18. 75 FR 29917 - Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation

    Science.gov (United States)

    2010-05-28

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX09 Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation AGENCY: Fish and Wildlife Service, Interior. ACTION: Final... on October 27, 2003, to create regulations governing migratory bird rehabilitation in the...

  19. 78 FR 35844 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2013-06-14

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2013-14 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2013-14 hunting season. This supplement to the...

  20. 76 FR 36508 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2011-06-22

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2011-12 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2011-12 hunting season. This supplement to the...

  1. 77 FR 42919 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

    Science.gov (United States)

    2012-07-20

    ... July 20, 2012 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations; Notice of Meetings...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird...

  2. 78 FR 67183 - Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird...

    Science.gov (United States)

    2013-11-08

    ... Fish and Wildlife Service Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird Surveys AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice; request for... Bird Treaty Act (16 U.S.C. 703-711) and the Fish and Wildlife Act of 1956 (16 U.S.C. 742d)...

  3. 78 FR 27927 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Science.gov (United States)

    2013-05-13

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule. SUMMARY: We propose to revise the regulations that allow control of depredating birds in some counties...

  4. 78 FR 65578 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Science.gov (United States)

    2013-11-01

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We revise the regulations that allow control of depredating birds in California. We specify the counties...

  5. Avian Assemblages at Bird Baths: A Comparison of Urban and Rural Bird Baths in Australia.

    Science.gov (United States)

    Cleary, Gráinne P; Parsons, Holly; Davis, Adrian; Coleman, Bill R; Jones, Darryl N; Miller, Kelly K; Weston, Michael A

    2016-01-01

    Private gardens provide habitat and resources for many birds living in human-dominated landscapes. While wild bird feeding is recognised as one of the most popular forms of human-wildlife interaction, almost nothing is known about the use of bird baths. This citizen science initiative explores avian assemblages at bird baths in private gardens in south-eastern Australia and how this differs with respect to levels of urbanisation and bioregion. Overall, 992 citizen scientists collected data over two, four-week survey periods during winter 2014 and summer 2015 (43% participated in both years). Avian assemblages at urban and rural bird baths differed between bioregions with aggressive nectar-eating species influenced the avian assemblages visiting urban bird baths in South Eastern Queensland, NSW North Coast and Sydney Basin while introduced birds contributed to differences in South Western Slopes, Southern Volcanic Plains and Victorian Midlands. Small honeyeaters and other small native birds occurred less often at urban bird baths compared to rural bird baths. Our results suggest that differences between urban versus rural areas, as well as bioregion, significantly influence the composition of avian assemblages visiting bird baths in private gardens. We also demonstrate that citizen science monitoring of fixed survey sites such as bird baths is a useful tool in understanding large-scale patterns in avian assemblages which requires a vast amount of data to be collected across broad areas.

  6. Surveillance for highly pathogenic avian influenza virus in wild birds during outbreaks in domestic poultry, Minnesota, 2015

    Science.gov (United States)

    Jennelle, Christopher S.; Carstensen, Michelle; Hildebrand, Erik C.; Cornicelli, Louis; Wolf, Paul C.; Grear, Daniel; Ip, Hon S.; VanDalen, Kaci K.; Minicucci, Larissa A.

    2016-01-01

    In 2015, a major outbreak of highly pathogenic avian influenza virus (HPAIV) infection devastated poultry facilities in Minnesota, USA. To clarify the role of wild birds, we tested 3,139 waterfowl fecal samples and 104 sick and dead birds during March 9–June 4, 2015. HPAIV was isolated from a Cooper’s hawk but not from waterfowl.

  7. Sex determination in 58 bird species and evaluation of CHD gene as a universal molecular marker in bird sexing.

    Science.gov (United States)

    Vucicevic, Milos; Stevanov-Pavlovic, Marija; Stevanovic, Jevrosima; Bosnjak, Jasna; Gajic, Bojan; Aleksic, Nevenka; Stanimirovic, Zoran

    2013-01-01

    The aim of this research was to test the CHD gene (Chromo Helicase DNA-binding gene) as a universal molecular marker for sexing birds of relatively distant species. The CHD gene corresponds to the aim because of its high degree of conservation and different lengths in Z and W chromosomes due to different intron sizes. DNA was isolated from feathers and the amplification of the CHD gene was performed with the following sets of polymerase chain reaction (PCR) primers: 2550F/2718R and P2/P8. Sex determination was attempted in 284 samples of 58 bird species. It was successful in 50 bird species; in 16 of those (Alopochen aegyptiacus, Ara severus, Aratinga acuticaudata, Bucorvus leadbeateri, Cereopsis novaehollandiae, Columba arquatrix, Corvus corax, C. frugilegus, Cyanoliseus patagonus, Guttera plumifera, Lamprotornis superbus, Milvus milvus, Neophron percnopterus, Ocyphaps lophotes, Podiceps cristatus, and Poicephalus senegalus), it was carried out for the first time using molecular markers and PCR. It is reasonable to assume that extensive research is necessary to define the CHD gene as a universal molecular marker for successful sex determination in all bird species (with exception of ratites). The results of this study may largely contribute to the aim.

  8. Technology demonstration by the BIRD-mission

    Science.gov (United States)

    Brieß, K.; Bärwald, W.; Gill, E.; Kayal, H.; Montenbruck, O.; Montenegro, S.; Halle, W.; Skrbek, W.; Studemund, H.; Terzibaschian, T.; Venus, H.

    2005-01-01

    Small satellites have to meet a big challenge: to answer high-performance requirements by means of small equipment and especially of small budgets. Out of all aspects the cost aspect is one of the most important driver for small satellite missions. To keep the costs within the low-budget frame (in comparison to big missions) the demonstration of new and not space-qualified technologies for the spacecraft is one key point in fulfilling high-performance mission requirements. Taking this into account the German DLR micro-satellite mission BIRD (Bi-spectral Infra-Red Detection) has to demonstrate a high-performance capability of spacecraft bus by using and testing new technologies basing on a mixed parts and components qualification level. The basic approach for accomplishing high-performance capability for scientific mission objectives under low-budget constraints is characterized by using state-of-the-art technologies, a mixed strategy in the definition of the quality level of the EEE parts and components, a tailored quality management system according to ISO 9000 and ECSS, a risk management system, extensive redundancy strategies, extensive tests especially on system level, large designs margins (over-design), robust design principles. The BIRD-mission is dedicated to the remote sensing of hot spot events like vegetation fires, coal seam fires or active volcanoes from space and to the space demonstration of new technologies. For these objectives a lot of new small satellite technologies and a new generation of cooled infrared array sensors suitable for small satellite missions are developed to fulfil the high scientific requirements of the mission. Some basic features of the BIRD spacecraft bus are compact micro satellite structure with high mechanical stability and stiffness, envelope qualification for several launchers, cubic shape in launch configuration with dimensions of about 620×620×550mm3 and variable launcher interface, mass ratio bus:payload = 62 kg:30

  9. SEROLOGICAL EVIDENCE OF AVIAN PARAMYXOVIRUS-2 INFECTION IN BACKYARD AND COMMERCIAL POULTRY BIRDS IN SAUDI ARABIA

    Directory of Open Access Journals (Sweden)

    A. N. ALKHALAF

    2009-07-01

    Full Text Available Serological survey was conducted to detect avian paramyxovirus serotype-2 (APMV-2 antibodies in commercial and backyard bird flocks, using Enzyme-linked immunosorbent assay (ELISA and haemagglutination inhibition (HI test. Sera were collected from 212 commercial and 56 backyard birds. Age of commercial birds ranged from one-day old to 62 weeks. In the backyard birds, seroprevalence of APVM-2 was 71.42 and 78.57%, whereas this seroprevalence was 52.35 and 60.84% using the HI test and the ELISA, respectively in commercial poultry birds. No antibodies against APMV-2 were detected in 1-5 days old chicks with either test. The HI test showed the highest positive samples (P<0.05 of APMV-2 in 19-35 days age group (58.33%, followed by age group 11-18 weeks (51.35% and 25-62 weeks (47.05%. Similarly, ELISA also showed the highest positive samples of APMV-2 (68.75% in 19-35 days age group (P<0.05, followed by age group 11-18 weeks (62.16% and 25-62 weeks (56.86%. In conclusion, this study indicated the presence of antibodies to APMV-2 among backyard and commercial poultry birds in Saudi Arabia.

  10. THE BIODIVERSITY AT SANDI BIRD SANCTUARY, HARDOI WITH SPECIAL REFERENCE TO MIGRATORY BIRDS

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2013-09-01

    Full Text Available Indian subcontinent plays host to a number of migratory birds in summers as well as winters. It is estimated that over hundred species of migratory birds fly to India, either in search of feeding grounds or to escape the severe winter of their native habitat. Sandi bird sanctuary was created in 1990 in order to protect and conserve the natural habitation and surroundings and also the marine vegetation for the migratory birds, as well as for the local people of the region. The term migration is used to describe movements of populations of birds or other animals. There are three types of migrants. One way to look at migration is to consider the distances traveled. The pattern of migration can vary within each category, but is most variable in short and medium distance migrants. The origin of migration is related to the distance traveled. The birds migrating through the area, take shelter on the river front before going to the Sandi Bird sanctuary. The birds generally migrate in the winter months of October-November-December. Bird sanctuary is a popular tourist location. Sandi particularly attracts ornithologists and bird watchers, as many rare migratory birds take refuge in the sanctuary. The bird watching camps arranged to observe the migratory birds at Sandi Bird Sanctuary in the month of October and November 2012. The migratory birds at Sandi Bird Sanctuary include great crested grebe, white storks, black lbis, glossy lbis, spoonbill, ruddy shelduck, pin tail, sholveller, spot bill duck, mallard, gadwall, wigeon, tufted pochard, gargancey teal, common teal, cotton teal, grey lag goose, coot, black tailed godwit, painted stock pin tail snipe, marsh sand piper, common tern, river tern, magpie robin, white wagtail, pied wagtail, common snipe, starlings, white lbis, red crested pochard, common pochard, painted stock, black lbis, curlew, Indian skimmer etc. The resident birds at Sandi Bird Sanctuary include little grebe, darter, purple heron, grey

  11. Use of multiple modes of flight subsidy by a soaring terrestrial bird, the golden eagle Aquila chrysaetos, when on migration

    Science.gov (United States)

    Katzner, Todd E.; Turk, Philip J.; Duerr, Adam E.; Miller, Tricia A.; Lanzone, Michael J.; Cooper, Jeff L.; Brandes, David; Tremblay, Junior A.; Lemaître, Jérôme

    2015-01-01

    Large birds regularly use updrafts to subsidize flight. Although most research on soaring bird flight has focused on use of thermal updrafts, there is evidence suggesting that many species are likely to use multiple modes of subsidy. We tested the degree to which a large soaring species uses multiple modes of subsidy to provide insights into the decision-making that underlies flight behaviour. We statistically classified more than 22 000 global positioning satellite–global system for mobile communications telemetry points collected at 30-s intervals to identify the type of subsidized flight used by 32 migrating golden eagles during spring in eastern North America. Eagles used subsidized flight on 87% of their journey. They spent 41.9% ± 1.5 (, range: 18–56%) of their subsidized northbound migration using thermal soaring, 45.2% ± 2.1 (12–65%) of time gliding between thermals, and 12.9% ± 2.2 (1–55%) of time using orographic updrafts. Golden eagles responded to the variable local-scale meteorological events they encountered by switching flight behaviour to take advantage of multiple modes of subsidy. Orographic soaring occurred more frequently in morning and evening, earlier in the migration season, and when crosswinds and tail winds were greatest. Switching between flight modes allowed migration for relatively longer periods each day and frequent switching behaviour has implications for a better understanding of avian flight behaviour and of the evolution of use of subsidy in flight. PMID:26538556

  12. Affinity for natal environments by dispersers impacts reproduction and explains geographical structure of a highly mobile bird.

    Science.gov (United States)

    Fletcher, Robert J; Robertson, Ellen P; Wilcox, Rebecca C; Reichert, Brian E; Austin, James D; Kitchens, Wiley M

    2015-09-07

    Understanding dispersal and habitat selection behaviours is central to many problems in ecology, evolution and conservation. One factor often hypothesized to influence habitat selection by dispersers is the natal environment experienced by juveniles. Nonetheless, evidence for the effect of natal environment on dispersing, wild vertebrates remains limited. Using 18 years of nesting and mark-resight data across an entire North American geographical range of an endangered bird, the snail kite (Rostrhamus sociabilis), we tested for natal effects on breeding-site selection by dispersers and its consequences for reproductive success and population structure. Dispersing snail kites were more likely to nest in wetlands of the same habitat type (lacustrine or palustrine) as their natal wetland, independent of dispersal distance, but this preference declined with age and if individuals were born during droughts. Importantly, dispersing kites that bred in natal-like habitats had lower nest success and productivity than kites that did not. These behaviours help explain recently described population connectivity and spatial structure across their geographical range and reveal that assortative breeding is occurring, where birds are more likely to breed with individuals born in the same wetland type as their natal habitat. Natal environments can thus have long-term and large-scale effects on populations in nature, even in highly mobile animals.

  13. Coping with uncertainty: woodpecker finches (Cactospiza pallida from an unpredictable habitat are more flexible than birds from a stable habitat.

    Directory of Open Access Journals (Sweden)

    Sabine Tebbich

    Full Text Available Behavioural flexibility is thought to be a major factor in evolution. It may facilitate the discovery and exploitation of new resources, which in turn may expose populations to novel selective forces and facilitate adaptive radiation. Darwin's finches are a textbook example of adaptive radiation. They are fast learners and show a range of unusual foraging techniques, probably as a result of their flexibility. In this study we aimed to test whether variability of the environment is correlated with flexibility. We compared woodpecker finches from a dry area (hereafter, Arid Zone, where food availability is variable, with individuals from a cloud forest (hereafter, Scalesia zone where food abundance is stable. As parameters for flexibility, we measured neophilia and neophobia, which are two aspects of reaction to novelty, reversal learning and problem-solving. We found no differences in performance on a problem-solving task but, in line with our prediction, individuals from the Arid Zone were significantly faster reversal learners and more neophilic than their conspecifics from the Scalesia zone. The latter result supports the notion that environmental variability drives flexibility. In contrast to our prediction, Arid Zone birds were even more neophobic than birds from the Scalesia Zone. The latter result could be the consequence of differences in predation pressure between the two vegetation zones.

  14. Use of multiple modes of flight subsidy by a soaring terrestrial bird, the golden eagle Aquila chrysaetos, when on migration.

    Science.gov (United States)

    Katzner, Todd E; Turk, Philip J; Duerr, Adam E; Miller, Tricia A; Lanzone, Michael J; Cooper, Jeff L; Brandes, David; Tremblay, Junior A; Lemaître, Jérôme

    2015-11-01

    Large birds regularly use updrafts to subsidize flight. Although most research on soaring bird flight has focused on use of thermal updrafts, there is evidence suggesting that many species are likely to use multiple modes of subsidy. We tested the degree to which a large soaring species uses multiple modes of subsidy to provide insights into the decision-making that underlies flight behaviour. We statistically classified more than 22 000 global positioning satellite-global system for mobile communications telemetry points collected at 30-s intervals to identify the type of subsidized flight used by 32 migrating golden eagles during spring in eastern North America. Eagles used subsidized flight on 87% of their journey. They spent 41.9% ± 1.5 ([Formula: see text], range: 18-56%) of their subsidized northbound migration using thermal soaring, 45.2% ± 2.1 (12-65%) of time gliding between thermals, and 12.9% ± 2.2 (1-55%) of time using orographic updrafts. Golden eagles responded to the variable local-scale meteorological events they encountered by switching flight behaviour to take advantage of multiple modes of subsidy. Orographic soaring occurred more frequently in morning and evening, earlier in the migration season, and when crosswinds and tail winds were greatest. Switching between flight modes allowed migration for relatively longer periods each day and frequent switching behaviour has implications for a better understanding of avian flight behaviour and of the evolution of use of subsidy in flight.

  15. 声振检测方法的发展%Evolution of the Acoustic Impact Testing Method

    Institute of Scientific and Technical Information of China (English)

    邬冠华; 林俊明; 任吉林; 周昌智

    2011-01-01

    依据激励方式的不同,分别从敲击检测和声阻检测方法两个方面对声振检测方法进行了介绍.敲击检测方法主要分整体振动检测法(或车轮敲击法)和局部振动检测法(或硬币敲击法),声阻检测法主要分机械阻抗法和局部共振检测法.声振检测方法尽管很早以前就已经出现了,但至今主要还停留在经验性的应用层面.对各种声振检测方法的基本原理及其发展作简要论述,希望起到抛砖引玉的作用,吸引业界关注该方法发展和应用的同仁共同来推进它的技术进步.%The acoustic impact testing method is presented with two different excitation methods: the tap testing method and the acoustic impedance testing method.The tap testing method includes the whole vibration testing (wheel-tap test) method and the local vibration testing method( coin-tap test), and the acoustic impedance method has the mechanical impedance method and the local resonance testing method.Though the acoustic impact testing method has a long history in testing activities, most concerns of this method are only restricted in its experiential applications.Here, the principals and their developments of several branches of the acoustic impact testing method are covered, with the main purpose to improve this old but effective method with the help of the people who concern its development and applications.

  16. Climate change in our backyards: the reshuffling of North America's winter bird communities.

    Science.gov (United States)

    Princé, Karine; Zuckerberg, Benjamin

    2015-02-01

    Much of the recent changes in North American climate have occurred during the winter months, and as result, overwintering birds represent important sentinels of anthropogenic climate change. While there is mounting evidence that bird populations are responding to a warming climate (e.g., poleward shifts) questions remain as to whether these species-specific responses are resulting in community-wide changes. Here, we test the hypothesis that a changing winter climate should favor the formation of winter bird communities dominated by warm-adapted species. To do this, we quantified changes in community composition using a functional index--the Community Temperature Index (CTI)--which measures the balance between low- and high-temperature dwelling species in a community. Using data from Project FeederWatch, an international citizen science program, we quantified spatiotemporal changes in winter bird communities (n = 38 bird species) across eastern North America and tested the influence of changes in winter minimum temperature over a 22-year period. We implemented a jackknife analysis to identify those species most influential in driving changes at the community level and the population dynamics (e.g., extinction or colonization) responsible for these community changes. Since 1990, we found that the winter bird community structure has changed with communities increasingly composed of warm-adapted species. This reshuffling of winter bird communities was strongest in southerly latitudes and driven primarily by local increases in abundance and regional patterns of colonization by southerly birds. CTI tracked patterns of changing winter temperature at different temporal scales ranging from 1 to 35 years. We conclude that a shifting winter climate has provided an opportunity for smaller, southerly distributed species to colonize new regions and promote the formation of unique winter bird assemblages throughout eastern North America.

  17. Lead Poisoning in Wild Birds

    Science.gov (United States)

    Lahner, Lesanna L.; Franson, J. Christian

    2009-01-01

    Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as paint and fuel, but it is still commonly used in ammunition for hunting upland game birds, small mammals, and large game animals, as well as in fishing tackle. Wild birds, such as mourning doves, bald eagles, California condors, and loons, can die from the ingestion of one lead shot, bullet fragment, or sinker. According to a recent study on loon mortality, nearly half of adult loons found sick or dead during the breeding season in New England were diagnosed with confirmed or suspected lead poisoning from ingestion of lead fishing weights. Recent regulations in some states have restricted the use of lead ammunition on certain upland game hunting areas, as well as lead fishing tackle in areas frequented by common loons and trumpeter swans. A variety of alternatives to lead are available for use in hunting, shooting sports, and fishing activities.

  18. Local equilibrium in bird flocks

    Science.gov (United States)

    Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    2016-12-01

    The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

  19. The learning advantage: bird species that learn their song show a tighter adjustment of song to noisy environments than those that do not learn.

    Science.gov (United States)

    Ríos-Chelén, Alejandro Ariel; Salaberria, C; Barbosa, I; Macías Garcia, C; Gil, D

    2012-11-01

    Song learning has evolved within several avian groups. Although its evolutionary advantage is not clear, it has been proposed that song learning may be advantageous in allowing birds to adapt their songs to the local acoustic environment. To test this hypothesis, we analysed patterns of song adjustment to noisy environments and explored their possible link to song learning. Bird vocalizations can be masked by low-frequency noise, and birds respond to this by singing higher-pitched songs. Most reports of this strategy involve oscines, a group of birds with learning-based song variability, and it is doubtful whether species that lack song learning (e.g. suboscines) can adjust their songs to noisy environments. We address this question by comparing the degree of song adjustment to noise in a large sample of oscines (17 populations, 14 species) and suboscines (11 populations, 7 species), recorded in Brazil (Manaus, Brasilia and Curitiba) and Mexico City. We found a significantly stronger association between minimum song frequency and noise levels (effect size) in oscines than in suboscines, suggesting a tighter match in oscines between song transmission capacity and ambient acoustics. Suboscines may be more vulnerable to acoustic pollution than oscines and thus less capable of colonizing cities or acoustically novel habitats. Additionally, we found that species whose song frequency was more divergent between populations showed tighter noise-song frequency associations. Our results suggest that song learning and/or song plasticity allows adaptation to new habitats and that this selective advantage may be linked to the evolution of song learning and plasticity.

  20. Diet and body temperature in mammals and birds

    OpenAIRE

    Clarke, Andrew; O'Connor, Mary I.

    2014-01-01

    Aim We test the hypothesis that endotherm body temperature varies with diet. Location Global terrestrial ecosystems. Methods We compile data from the literature on diet and body temperature in mammals and birds. We analyse these and demonstrate global macrophysiological patterns. Results In mammals, carnivores overall have a lower mean body temperature (Tb) than either herbivores or omnivores. However, within carnivores, those taking vertebrate prey have a h...

  1. Effects of bird-feeding activities on the health of wild birds.

    Science.gov (United States)

    Wilcoxen, Travis E; Horn, David J; Hogan, Brianna M; Hubble, Cody N; Huber, Sarah J; Flamm, Joseph; Knott, Madeline; Lundstrom, Lisa; Salik, Faaria; Wassenhove, Samantha J; Wrobel, Elizabeth R

    2015-01-01

    Among the most popular reasons that people feed wild birds is that they want to help birds. The extent to which supplemental food helps birds, however, is not well established. From spring 2011 to spring 2014, we examined how feeding of wild birds influences the health of individual birds at forested sites in central Illinois, USA. Specifically, we compared three forested sites where we provided supplemental food with three forested sites for which no supplemental food was available and monitored changes in the individual health of birds. In addition, we determined whether any changes in bird health had occurred after feeders had been removed from sites 10 months before. Generally, the individual health of birds improved with supplemental feeding, including increased antioxidant levels, reduced stress (heterophil-to-lymphocyte ratio) and more rapid feather growth. In some species, we also found improved body condition index scores and innate immune defense. The difference among sites was not present 10 months after feeders were removed, suggesting that the impact on health was indeed related to supplemental feeding. Potential negative effects of supplemental feeding were also found, including an increase in infectious disease prevalence among individual birds at forested sites where supplemental food was offered. Birds with clear signs of pathology showed deficits in most of the physiological metrics in which birds at feeder sites typically showed improved health condition. At the peak of prevalence of infectious disease, 8.3% of all birds at feeders exhibited symptoms of conjunctivitis, pox, dermal disease or cloacal disease. We found both positive and negative impacts of wild bird feeding, and that, in general, birds that had access to supplemental food were in better physiological condition. Moreover, the negative effects we found may be mitigated by hobbyists engaging in safer bird-feeding practices.

  2. Fruit color preference by birds and applications to ecological restoration

    Directory of Open Access Journals (Sweden)

    B. L. Gagetti

    Full Text Available Abstract Ecological restoration aims to retrieve not only the structure but also the functionality of ecosystems. Frugivorous birds may play an important role in this process due to their efficiency in seed dispersal. Color perception in these animals is highly developed, and then the colors of fleshy fruits may provide important clues for choosing plant species for restoration plans. This study aims to integrate bird color preferences and restoration of degraded areas, with an objective to evaluate the potential attractiveness to birds by colored fruits. We carried out an experiment with 384 artificial fruits made of edible modeling clay with the following colors: black, blue, green and red, with 96 fruits of each color in six sites, including four restored areas and two second-growth forest fragments. We also tested the possible effect of light intensity on fruit consumption by color. A total of 120 (38.6% were assumed to be consumed by birds, and the fruit consumption varied in response to the location and light incidence. Consumption of black and blue fruits was not related to site by chance. Notwithstanding, red and black fruits were consumed significantly more than any other colors, emphasizing bird preference to these colors, regardless of location. Enrichment with shade tolerant shrubs or forest species with black or red fruits may be an alternative way to manage established restorations. In recently established or new restorations, one may introduce pioneer shrubs or short-lived forest species which have blue fruits, but also those having black or red ones.

  3. The Numerical Competency of Two Bird Species (Corvus splendens and Acridotheres tristis)

    OpenAIRE

    2014-01-01

    We conducted a series of experiments to test the numerical competency of two species of birds, Corvus splendens (House Crow) and Acridotheres tristis (Common Myna). Both species were allowed to choose from seven different groups of mealworms with varying proportions. We considered the birds to have made a correct choice when it selected the food group with the highest number of mealworms. Our overall results indicated that the Common Myna is able to count numbers (161 successful choices out o...

  4. The Netherlands Bird Avoidance Model, Final Report

    NARCIS (Netherlands)

    Shamoun-Baranes, J.; Bouten, W.; Sierdsema, H.; van Belle, J.; van Gasteren, J.R.; van Loon, E.E.

    2006-01-01

    The NL-BAM was developed as a web-based decision support tool to be used by the bird hazard avoidance experts in the ecology unit of the Royal Netherlands Air Force. The NL-BAM will be used together with the ROBIN 4 radar system to provide BirdTAMS, for real time warnings and flight planning and to

  5. 14 CFR 33.76 - Bird ingestion.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.76 Bird ingestion. (a... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird ingestion. 33.76 Section 33.76... takeoff thrust or power. (2) The engine inlet throat area as used in this section to determine the...

  6. Fernbank Forest Birds in the Summer.

    Science.gov (United States)

    Schmalz, Georgann

    1991-01-01

    Provided is a listing of the common nesting birds and the neotropical migrant birds with nesting records in the approximate 65 acres of Fernbank Forest which is a preserve of mature urban hardwoods and pines within 10 miles of downtown Atlanta and a relic of what was once a large, uninterrupted tract of the Piedmont forest. (JJK)

  7. Accurate Segmentation for Infrared Flying Bird Tracking

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hong; HUANG Ying; LING Haibin; ZOU Qi; YANG Hao

    2016-01-01

    Bird strikes present a huge risk for air ve-hicles, especially since traditional airport bird surveillance is mainly dependent on inefficient human observation. For improving the effectiveness and efficiency of bird monitor-ing, computer vision techniques have been proposed to detect birds, determine bird flying trajectories, and pre-dict aircraft takeoff delays. Flying bird with a huge de-formation causes a great challenge to current tracking al-gorithms. We propose a segmentation based approach to enable tracking can adapt to the varying shape of bird. The approach works by segmenting object at a region of inter-est, where is determined by the object localization method and heuristic edge information. The segmentation is per-formed by Markov random field, which is trained by fore-ground and background mixture Gaussian models. Exper-iments demonstrate that the proposed approach provides the ability to handle large deformations and outperforms the m ost state-of-the-art tracker in the infrared flying bird tracking problem.

  8. Ability of Slovakian Pupils to Identify Birds

    Science.gov (United States)

    Prokop, Pavol; Rodak, Rastislav

    2009-01-01

    A pupil's ability to identify common organisms is necessary for acquiring further knowledge of biology. We investigated how pupils were able to identify 25 bird species following their song, growth habits, or both features presented simultaneously. Just about 19% of birds were successfully identified by song, about 39% by growth habit, and 45% of…

  9. Two Good Places for Bird Lovers

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In the middle and lower reaches of the YangtzRiver,Poyang Lake and Dongting Lake are the towbiggest freshwater lakes in China and are also two ofthe most famous bird reserves in the country.Themagnificent scene of the large number of migrantbirds that fly over every winter is attracting more andmore bird lovers.

  10. Pheromones in birds: myth or reality?

    NARCIS (Netherlands)

    Caro, S.P.; Balthazart, J.

    2010-01-01

    Birds are anosmic or at best microsmatic… This misbelief persisted until very recently and has strongly influenced the outcome of communication studies in birds, with olfaction remaining neglected as compared to acoustic and visual channels. However, there is now clear empirical evidence showing tha

  11. Relative roles of grey squirrels, supplementary feeding, and habitat in shaping urban bird assemblages.

    Directory of Open Access Journals (Sweden)

    Colin Bonnington

    Full Text Available Non-native species are frequently considered to influence urban assemblages. The grey squirrel Sciurus carolinensis is one such species that is widespread in the UK and is starting to spread across Europe; it predates birds' nests and can compete with birds for supplementary food. Using distance sampling across the urbanisation intensity gradient in Sheffield (UK we test whether urban grey squirrels influence avian species richness and density through nest predation and competition for supplementary food sources. We also assess how urban bird assemblages respond to supplementary feeding. We find that grey squirrels slightly reduced the abundance of breeding bird species most sensitive to squirrel nest predation by reducing the beneficial impact of woodland cover. There was no evidence that grey squirrel presence altered relationships between supplementary feeding and avian assemblage structure. This may be because, somewhat surprisingly, supplementary feeding was not associated with the richness or density of wintering bird assemblages. These associations were positive during the summer, supporting advocacy to feed birds during the breeding season and not just winter, but explanatory capacity was limited. The amount of green space and its quality, assessed as canopy cover, had a stronger influence on avian species richness and population size than the presence of grey squirrels and supplementary feeding stations. Urban bird populations are thus more likely to benefit from investment in improving the availability of high quality habitats than controlling squirrel populations or increased investment in supplementary feeding.

  12. H5N1 surveillance in migratory birds in Java, Indonesia.

    Science.gov (United States)

    Stoops, Arthur C; Barbara, Katie A; Indrawan, Mochamad; Ibrahim, Ima N; Petrus, Wicaksana B; Wijaya, Susan; Farzeli, Arik; Antonjaya, Ungke; Sin, Lim W; Hidayatullah, N; Kristanto, Ige; Tampubolon, A M; Purnama, S; Supriatna, Adam; Burgess, Timothy H; Williams, Maya; Putnam, Shannon D; Tobias, Steve; Blair, Patrick J

    2009-12-01

    We sought to elucidate the role of migratory birds in transmission of H5N1 in an enzoonotic area. Resident, captive, and migratory birds were sampled at five sites in Java, Indonesia. Mist nets were used to trap birds. Birds were identified to species. RNA was extracted from swabs and reverse transcriptase polymerase chain reaction (RT-PCR) conducted for the HA and M genes of H5N1. Antibodies were detected by enzyme-linked immunosorbent assay and hemagglutination inhibition test. Between October 2006 and September 2007, a total of 4,067 captive, resident, and migratory birds comprising 98 species in 23 genera were sampled. The most commonly collected birds were the common sandpiper (6% of total), striated heron (3%), and the domestic chicken (14%). The overall prevalence of H5N1 antibodies was 5.3%. A significantly higher percentage of captive birds (16.1%) showed antibody evidence of H5N1 exposure when compared to migratory or resident birds. The greatest number of seropositive birds in each category were Muschovy duck (captive), striated heron (resident), and the Pacific golden plover (migratory). Seven apparently well captive birds yielded molecular evidence of H5N1 infection. Following amplification, the HA, NA, and M genes were analyzed. Phylogenetic analysis of the HA gene showed that the isolates were 97% similar to EU124153.1 A/chicken/West Java/Garut May 2006, an isolate obtained in a similar region of West Java. While no known markers of neuraminidase inhibitor resistance were found within the NA gene, M segment analysis revealed the V27A mutation known to confer resistance to adamantanes. Our results demonstrate moderate serologic evidence of H5N1 infection in captive birds, sampled in five sites in Java, Indonesia, but only occasional infection in resident and migratory birds. These data imply that in an enzoonotic region of Indonesia the role of migratory birds in transmission of H5N1 is limited.

  13. Why do some adult birds skip breeding? A hormonal investigation in a long-lived bird.

    Science.gov (United States)

    Goutte, Aurélie; Kriloff, Marion; Weimerskirch, Henri; Chastel, Olivier

    2011-10-23

    Skipping reproduction is often observed in long-lived organisms, but proximate mechanisms remain poorly understood. Since young and/or very old snow petrels (Pagodroma nivea) commonly skip breeding, we tested whether they are physiologically able to breed during the pre-laying stage. To do so, we measured the ability of known-age (11-45 years old) petrels to release luteinizing hormone (LH, a crucial driver for breeding), by injecting exogenous gonadotropin-releasing hormone (GnRH). Although young petrels exhibited low baseline LH levels, they were able to elevate LH levels after a GnRH challenge. Moreover, young and very old petrels showed a stronger decrease in LH levels after the 10 min post-GnRH injection compared with middle-aged petrels. Birds that skipped breeding were as able as breeders to release LH after a GnRH challenge, indicating that they had functional pituitaries. However, the decision to skip reproduction was linked to a strong LH decrease after the 10 min post-GnRH injection. Our result suggests that the youngest and the oldest petrels fail to maintain elevated baseline LH levels, thereby do not initiate reproductive activities. Skipping reproduction in long-lived birds probably results from age-related changes in the dynamics of the hypothalamic-pituitary-gonadal (HPG) axis function.

  14. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  15. Seroprevalence and risk factors associated with hepatitis E virus infection in three species of pet birds in northwest China.

    Science.gov (United States)

    Cong, Wei; Meng, Qing-Feng; Shan, Xiao-Feng; Sun, Wu-Wen; Qin, Si-Yuan; Zhang, Xiao-Xuan; Huang, Si-Yang; Qian, Ai-Dong

    2014-01-01

    Hepatitis E virus (HEV), the causative agent of hepatitis E, has been reported in a wide variety of animals, including birds, but little is known of HEV infection in pet birds in northwest China. The objective of the present investigation was to examine HEV seroprevalence in three species of pet birds, namely, Eurasian siskin, Oriental skylark, and black-tailed grosbeak from Gansu. Serum samples collected from 685 pet birds from August 2011 to September 2012 were examined independently for the presence of antibodies against HEV. A total of 59 (8.31%) pet birds were tested positive for HEV antibodies by the commercially available enzyme immunoassay kits. Of these, the seroprevalence was diverse in different species pet birds; the most frequent level was 10.83% (39/360) in Eurasian siskin, followed by 6.57% (19/289) in Oriental skylark, and 2.29% (1/36) in black-tailed grosbeak. Age and collecting region of pet birds were the main risk factors associated with HEV infection. The present study firstly revealed the seroprevalence of HEV infection in three species of pet birds in northwest China, which provided the baseline data for taking comprehensive countermeasures and measures for effectively preventing and controlling HEV infection in birds.

  16. Birds caught inspider webs inAsia

    Institute of Scientific and Technical Information of China (English)

    Bruno A. Walther

    2016-01-01

    A recent global review of birds caught in spider webs reported only three Asian cases. Given this surprisingly low number, I made a concerted effort to obtain additional Asian cases from the literature, the internet, and ifeld workers. I present a total of 56 Asian cases which pertain to 33 bird species. As in the global dataset, mostly small bird species were caught in spider webs, with a mean body mass of 17.5 g and a mean wing chord length of 73.1 mm. Conse‑quently, birds with a body mass >30 g were very rarely caught. This Asian review corroborates the global review that smaller birds are more likely to be caught and thatNephila spiders are most likely to be the predators. Continuous monitoring of spider webs is recommended to ascertain the frequency of these events.

  17. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale. The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...... also molt their flight feathers at this location and intraspecific interactions are non-aggressive. The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables...

  18. From road to lab to math: the co-evolution of technological, regulatory, and organizational innovations for automotive crash testing.

    Science.gov (United States)

    Leonardi, Paul M

    2010-04-01

    Today, in the midst of economic crisis, senior executives at US automakers and influential industry analysts frequently reflect on the progression that safety testing has taken from the crude trials done on the road, to controlled laboratory experiments, and to today's complex math-based simulation models. They use stories of this seemingly linear and natural sequence to justify further investment in simulation technologies. The analysis presented in this paper shows that change in the structures of automakers' organizations co-evolved with regulations specifying who was at fault in vehicle impacts, how vehicles should be built to withstand the force of an impact, and how testing should be done to assure that vehicles met those requirements. Changes in the regulatory environment were bolstered by new theories about crash test dynamics and changing technologies with which to test those theories. Thus, as new technological and regulatory innovations co-evolved with innovations in organizational structuring, ideas about how to best conduct crash tests shifted and catalyzed new cycles of technological, regulatory, and organizational innovation. However, this co-evolutionary story tells us that the move from road to lab to math was not natural or linear as today's managerial rhetoric would have us believe. Rather, the logic of math-based simulation was the result of technological, regulatory and organizational changes that created an industry-wide ideology that supported the move toward math while making it appear natural within the shifting structure of the industry.

  19. Modelling of pavement materials on steel decks using the five-point bending test: Thermo mechanical evolution and fatigue damage

    Science.gov (United States)

    Arnaud, L.; Houel, A.

    2010-06-01

    This paper deals with the modelling of wearing courses on steel orthotropic decks such as the Millau viaduct in France. This is of great importance when dealing with durability: due to the softness of such a support, the pavement is subjected to considerable strains that may generate top-down cracks in the layer at right angles of the orthotropic plate stiffeners and shear cracks at the interface between pavement and steel. Therefore, a five-point bending fatigue test was developed and improved since 2003 at the ENTPE laboratory, to test different asphalt concrete mixes. This study aims at modelling the mechanical behavior of the wearing course throughout the fatigue test by a finite element method (Comsol Multiphysics software). Each material - steel, sealing sheet, asphalt concrete layer - is considered and modelled. The modelling of asphalt concrete is complex since it is a heterogeneous material, a viscoelastic medium and it thermosensitive. The actual characteristics of the asphalt concrete (thermo physical parameter and viscoelastic complex modulus) are determined experimentally on cylindrical cores. Moreover, a damage law based on Miner's damage is included in the model. The modelling of the fatigue test leads to encouraging results. Finally, results from the model are compared to the experimental data obtained from the five-point bending fatigue test device. The experimental data are very consistent with the numerical simulation.

  20. Frequency of zoonotic bacteria among illegally traded wild birds in Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Rey Matias

    Full Text Available Abstract The illegal wildlife trade may increase the risk of infectious disease transmission, and it may not only cause disease outbreaks in humans but also threaten livestock, native wild populations, and ecosystems' health. Bird species may act as carriers in the transmission of enteric pathogens. However, epidemiological studies on zoonotic bacteria in wild birds are rare in Brazil. From March 2011 to March 2012, we investigated the frequency of Enterobacteriaceae in cloacal swab samples from 109 birds of the passerine and Psittacidae families. These birds were recovered from illegal trade in Rio de Janeiro, Brazil, and sent to a rehabilitation center. Gram-negative bacteria were isolated from 86 wild birds (78.9%. A mean (±SD of 1.68 (±1.30 different bacterial species were isolated per bird, with a maximum of five bacterial species from three bird species. The most frequently isolated bacteria were Escherichia coli, followed by Enterobacter spp., Klebsiella pneumoniae and other enteric bacteria. Salmonella ser. Typhimurium was isolated from a Temminck's seedeater (Sporophila falcirostris, and two Salmonella ser. Panama were isolated from two specimens of chestnut-capped blackbird (Chrysomus ruficapillus. Of the 70 selected bacterial isolates, 60 exhibited antibiotic resistance. The resistance patterns varied from one to nine of the antibiotics tested. Resistance to ceftiofur was the most prevalent, followed by ampicillin and ceftriaxone. The dissemination potential of resistant strains in situations typically seen in the management of captive birds may become a problem for the conservation of natural bird populations and for public health.

  1. Forest fragmentation and bird community dynamics: inference at regional scales

    Science.gov (United States)

    Boulinier, T.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Flather, C.H.; Pollock, K.H.

    2001-01-01

    With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which could explain higher temporal variability in species richness. To investigate such potential landscape effects at a regional scale, we merged two independent, large-scale monitoring efforts: the North American Breeding Bird Survey (BBS) and the Land Use and Land Cover Classification data from the U.S. Geological Survey. We used methods that accounted for heterogeneity in the probability of detecting species to estimate species richness and temporal changes in the bird communities for BBS routes in three mid-Atlantic U.S. states. Forest breeding bird species were grouped prior to the analyses into area-sensitive and non-area-sensitive species according to previous studies. We tested predictions relating measures of forest structure at one point in time (1974) to species richness at that time and to parameters of forest bird community change over the following 22-yr-period (1975-1996). We used the mean size of forest patches to characterize landscape structure, as high correlations among landscape variables did not allow us to disentangle the relative roles of habitat fragmentation per se and habitat loss. As predicted, together with lower species richness for area-sensitive species on routes surrounded by landscapes with lower mean forest-patch size, we found higher mean year-to-year rates of local extinction. Moreover, the mean year-to-year rates of local turnover (proportion of locally new species) for area-sensitive species were also higher in landscapes with lower mean forest-patch size. These associations were not observed for the non-area-sensitive species group. These

  2. Absolute properties of the eclipsing binary system AQ Serpentis: A stringent test of convective core overshooting in stellar evolution models

    CERN Document Server

    Torres, Guillermo; Lacy, Claud H Sandberg; Claret, Antonio

    2013-01-01

    We report differential photometric observations and radial-velocity measurements of the detached, 1.69-day period, double-lined eclipsing binary AQ Ser. Accurate masses and radii for the components are determined to better than 1.8% and 1.1%, respectively, and are M1 = 1.417 +/- 0.021 MSun, M2 = 1.346 +/- 0.024 MSun, R1 = 2.451 +/- 0.027 RSun, and R2 = 2.281 +/- 0.014 RSun. The temperatures are 6340 +/- 100 K (spectral type F6) and 6430 +/- 100 K (F5), respectively. Both stars are considerably evolved, such that predictions from stellar evolution theory are particularly sensitive to the degree of extra mixing above the convective core (overshoot). The component masses are different enough to exclude a location in the H-R diagram past the point of central hydrogen exhaustion, which implies the need for extra mixing. Moreover, we find that current main-sequence models are unable to match the observed properties at a single age even when allowing the unknown metallicity, mixing length parameter, and convective o...

  3. Absolute dimensions of solar-type eclipsing binaries. EF Aquarii: a G0 test for stellar evolution models

    CERN Document Server

    Vos, J; Jørgensen, U G; Østensen, R H; Claret, A; Hillen, M; Exter, K

    2012-01-01

    Recent studies have shown that stellar chromospheric activity, and its effect on convective energy transport in the envelope, is most likely the cause of significant radius and temperature discrepancies between theoretical evolution models and observations. We aim to determine absolute dimensions and abundances for the solar-type detached eclipsing binary EF Aqr, and to perform a detailed comparison with results from recent stellar evolutionary models. uvby-beta standard photometry was obtained with the Stromgren Automatic Telescope. The broadening function formalism was applied on spectra observed with HERMES at the Mercator telescope in La Palma, to obtain radial velocity curves. Masses and radii with a precision of 0.6% and 1.0% respectively have been established for both components of EF Aqr. The active 0.956 M_sol secondary shows star spots and strong Ca II H and K emission lines. The 1.224 M_sol primary shows signs of activity as well, but at a lower level. An [Fe/H] abundance of 0.00+-0.10 is derived w...

  4. Sero-survey of Avian Influenza in backyard poultry and wild bird species in Iran-2014.

    Science.gov (United States)

    Fallah Mehrabadi, M H; Bahonar, A R; Vasfi Marandi, M; Sadrzadeh, A; Tehrani, F; Salman, M D

    2016-06-01

    In almost all villages in Iran backyard birds, especially chickens, are kept for egg and meat production. AI H9N2 subtype is endemic in Iran. Therefore, estimation of AI prevalence among these birds is important to determine the risk of transmission of infection to commercial farms. The aim of this study was to estimate subclinical infections or previous exposure to H5, H7, and H9 subtypes and to identify potentially important determinants of prevalence of this infectious at premises level in backyard poultry, bird gardens, zoos, and wild bird markets in Iran. A survey was conducted using a cross-sectional design throughout the entire country. A total of 329 villages, seven bird gardens, three zoos and five wild bird markets were included. In each village four families that kept birds were included in the collection of biological samples and background information. The Enzyme-Linked Immunosorbent Assay (ELISA) was used as the screening test and all ELISA-positive samples were examined with the HI test to differentiate H5, H7, and H9. Among the bird gardens, eight of 15 premises (53.3%) were positive in both the ELISA test and HI for H9N2. Testing of samples collected in the villages revealed that 296 out of 329 villages (90%) had positive ELISA tests and also HI tests for H9. The HI-H9 mean titers in positive units were significantly higher than negative units (P.05). The results of this study showed that among the risk variables, mountainous area was a protective factor and lack of hygienic disposal of dead birds was a risk factor for AI; this was also observed in rural poultry. The high sero-prevalence of influenza H9N2 in rural domestic poultry indicates that the disease is endemic. It is necessary to include backyard poultry in any surveillance system and control strategy due to the existence of AIV in backyard poultry and the possibility of transmission of infection to commercial poultry farms. Implementation of an AI surveillance program and biosecurity

  5. Evidence for Repeated Independent Evolution of Migration in the Largest Family of Bats

    Science.gov (United States)

    Bisson, Isabelle-Anne; Safi, Kamran; Holland, Richard A.

    2009-01-01

    Background How migration evolved represents one of the most poignant questions in evolutionary biology. While studies on the evolution of migration in birds are well represented in the literature, migration in bats has received relatively little attention. Yet, more than 30 species of bats are known to migrate annually from breeding to non-breeding locations. Our study is the first to test hypotheses on the evolutionary history of migration in bats using a phylogenetic framework. Methods and Principal Findings In addition to providing a review of bat migration in relation to existing hypotheses on the evolution of migration in birds, we use a previously published supertree to formulate and test hypotheses on the evolutionary history of migration in bats. Our results suggest that migration in bats has evolved independently in several lineages potentially as the need arises to track resources (food, roosting site) but not through a series of steps from short- to long-distance migrants, as has been suggested for birds. Moreover, our analyses do not indicate that migration is an ancestral state but has relatively recently evolved in bats. Our results also show that migration is significantly less likely to evolve in cave roosting bats than in tree roosting species. Conclusions and Significance This is the first study to provide evidence that migration has evolved independently in bat lineages that are not closely related. If migration evolved as a need to track seasonal resources or seek adequate roosting sites, climate change may have a pivotal impact on bat migratory habits. Our study provides a strong framework for future research on the evolution of migration in chiropterans. PMID:19844569

  6. Lateralization of magnetic compass orientation in a migratory bird

    Science.gov (United States)

    Wiltschko, Wolfgang; Traudt, Joachim; Güntürkün, Onur; Prior, Helmut; Wiltschko, Roswitha

    2002-10-01

    Lateralization of brain functions, once believed to be a human characteristic, has now been found to be widespread among vertebrates. In birds, asymmetries of visual functions are well studied, with each hemisphere being specialized for different tasks. Here we report lateralized functions of the birds' visual system associated with magnetoperception, resulting in an extreme asymmetry of sensing the direction of the magnetic field. We found that captive migrants tested in cages with the magnetic field as the only available orientation cue were well oriented in their appropriate migratory direction when using their right eye only, but failed to show a significant directional preference when using their left eye. This implies that magnetoreception for compass orientation, assumed to take place in the eyes alongside the visual processes, is strongly lateralized, with a marked dominance of the right eye/left brain hemisphere.

  7. Can foraging ecology drive the evolution of body size in a diving endotherm?

    Directory of Open Access Journals (Sweden)

    Timothée R Cook

    Full Text Available Within a single animal species, different morphs can allow for differential exploitation of foraging niches between populations, while sexual size dimorphism can provide each sex with access to different resources. Despite being potentially important agents of evolution, resource polymorphisms, and the way they operate in wild populations, remain poorly understood. In this study, we examine how trophic factors can select for different body sizes between populations and sexes in a diving endotherm. Dive depth and duration are positively related to body size in diving birds and mammals, a relationship explained by a lower mass-specific metabolic rate and greater oxygen stores in larger individuals. Based on this allometry, we predict that selection for exploiting resources situated at different depths can drive the evolution of body size in species of diving endotherms at the population and sexual level. To test this prediction, we studied the foraging ecology of Blue-eyed Shags, a group of cormorants with male-biased sexual size dimorphism from across the Southern Ocean. We found that mean body mass and relative difference in body mass between sexes varied by up to 77% and 107% between neighbouring colonies, respectively. Birds from colonies with larger individuals dived deeper than birds from colonies with smaller individuals, when accounting for sex. In parallel, males dived further offshore and deeper than females and the sexual difference in dive depth reflected the level of sexual size dimorphism at each colony. We argue that body size in this group of birds is under intense selection for diving to depths of profitable benthic prey patches and that, locally, sexual niche divergence selection can exaggerate the sexual size dimorphism of Blue-eyed Shags initially set up by sexual selection. Our findings suggest that trophic resources can select for important geographic micro-variability in body size between populations and sexes.

  8. DNA barcoding techniques for avian influenza virus surveillance in migratory bird habitats.

    Science.gov (United States)

    Lee, Dong-Hun; Lee, Hyun-Jeong; Lee, Youn-Jeong; Kang, Hyun-Mi; Jeong, Ok-Mi; Kim, Min-Chul; Kwon, Ji-Sun; Kwon, Jun-Hun; Kim, Chang-Bae; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

    2010-04-01

    Avian influenza virus (AIV) circulates among free-ranging, wild birds. We optimized and validated a DNA barcoding technique for AIV isolation and host-species identification using fecal samples from wild birds. DNA barcoding was optimized using tissue and fecal samples from known bird species, and the method was shown to distinguish 26 bird species. Subsequently, fecal samples (n=743) collected from wild waterfowl habitats confirmed the findings from the laboratory tests. All identified AIV-positive hosts (n=35) were members of the order Anseriformes. We successfully applied the DNA barcoding technique to AIV surveillance and examined AIV epidemiology and host ecology in these wild waterfowl populations. This methodology may be useful in the design of AIV surveillance strategies.

  9. Mesurol as a bird repellent on wine grapes in Oregon and California

    Science.gov (United States)

    Hothem, R.L.; Mott, D.F.; DeHaven, R.W.; Guarino, J.L.

    1981-01-01

    Field tests were conducted in California and Oregon from July to October 1978 to evaluate the effectiveness of Mesurol as a repellent to reduce bird damage to ripening wine grapes. A block of vines composed of two similar, adjacent plots was delineated at each of 20 vineyards. One randomly chosen plot within each block was treated with up to three applications of Mesurol (75% wettable powder) at a mean rate of 3.1 kg/ha. Damage assessments at harvest showed that the treatment significantly reduced bird damage in both states, but the actual level of bird damage protection provided by the treatment could not be calculated. Based on bird censuses, the primary grape-depredating species in Oregon vineyards was the American robin (Turdus migratorius), whereas house finches (Carpodacus mexicanus), California quail (Lophortyx californicus), goldfinches (Spinus spp.), and robins were the primary species in California.

  10. Ethical advantages of using domestic bird species for magnetic orientation research.

    Science.gov (United States)

    Freire, Rafael

    2011-01-01

    Identifying the mechanism in birds that controls magnetic orientation behavior is proving elusive and is currently attracting a plethora of research activity. Much of this research involves wild birds that are caught in nets, tested and released. Ethical concerns regarding these experiments are likely to encompass the welfare of animals, their "rights" and conservation issues. Recently, Pekin ducks derived from migratory ancestors have been shown to posses a magnetic compass in a simple conditioning procedure. The use of domestic bird species provides a refinement in the ethics of animal experimentation since these birds are not caught in nets, are less fearful of humans and their use does not raise conservation concerns. The study of magnetic orientation is a high profile and fascinating areas of animal behavior research and one in which behavioral scientists should be seen to actively embrace the principles of the 3R's.

  11. Molecular characterization of AI viruses from poultry and wild bird surveillance in Denmark

    DEFF Research Database (Denmark)

    Larsen, Lars Erik; Krog, Jesper Schak; Madsen, Jesper J.

    Infection with avian influenza virus (AIV) in poultry may cause devastating disease although the same virus may not cause disease in wild birds. Since AI viruses can be exchanged between poultry and wild birds, surveillance in wild birds provides important knowledge for control of disease...... in poultry. AIV’s from the Danish wild bird active surveillance were characterized, focusing on viruses from 2012, and from outbreaks of AI in poultry in Denmark. The matrix (M) gene from more than 50 viruses of different subtypes and the hemagglutinin (HA) gene from more than 30 subtype H5 low pathogenic...... viruses were sequenced and compared by alignment and phylogenetic analyses. The aim was to evaluate: the origin of viruses from outbreaks of AI in Danish poultry, the design of active surveillance in Denmark, and the suitability of the molecular diagnostic RT-PCR tests employed. All M-genes from Danish...

  12. Effects of road networks on bird populations.

    Science.gov (United States)

    Kociolek, A V; Clevenger, A P; St Clair, C C; Proppe, D S

    2011-04-01

    One potential contributor to the worldwide decline of bird populations is the increasing prevalence of roads, which have several negative effects on birds and other vertebrates. We synthesized the results of studies and reviews that explore the effects of roads on birds with an emphasis on paved roads. The well-known direct effects of roads on birds include habitat loss and fragmentation, vehicle-caused mortality, pollution, and poisoning. Nevertheless, indirect effects may exert a greater influence on bird populations. These effects include noise, artificial light, barriers to movement, and edges associated with roads. Moreover, indirect and direct effects may act synergistically to cause decreases in population density and species richness. Of the many effects of roads, it appears that road mortality and traffic noise may have the most substantial effects on birds relative to other effects and taxonomic groups. Potential measures for mitigating the detrimental effects of roads include noise-reduction strategies and changes to roadway lighting and vegetation and traffic flow. Road networks and traffic volumes are projected to increase in many countries around the world. Increasing habitat loss and fragmentation and predicted species distribution shifts due to climate change are likely to compound the overall effects of roads on birds.

  13. Overseas seed dispersal by migratory birds.

    Science.gov (United States)

    Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi

    2016-01-13

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution.

  14. Impact of estuarine pollution on birds

    Science.gov (United States)

    Blus, L.J.; Wiemeyer, Stanley N.; Kerwin, J.A.; Stendell, R.C.; Ohlendorf, H.M.; Stickel, L.F.

    1977-01-01

    Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.

  15. Ecology of Avian Influenza Virus in Wild Birds in Tropical Africa.

    Science.gov (United States)

    Gaidet, Nicolas

    2016-05-01

    Several ecologic factors have been proposed to describe the mechanisms whereby host ecology and the environment influence the transmission of avian influenza viruses (AIVs) in wild birds, including bird's foraging behavior, migratory pattern, seasonal congregation, the rate of recruitment of juvenile birds, and abiotic factors. However, these ecologic factors are derived from studies that have been conducted in temperate or boreal regions of the Northern Hemisphere. These factors cannot be directly translated to tropical regions, where differences in host ecology and seasonality may produce different ecologic interactions between wild birds and AIV. An extensive dataset of AIV detection in wildfowl and shorebirds sampled across tropical Africa was used to analyze how the distinctive ecologic features of Afrotropical regions may influence the dynamics of AIV transmission in wild birds. The strong seasonality of rainfall and surface area of wetlands allows testing of how the seasonality of wildfowl ecology (reproduction phenology and congregation) is related to AIV seasonal dynamics. The diversity of the African wildfowl community provides the opportunity to investigate the respective influence of migratory behavior, foraging behavior, and phylogeny on species variation in infection rate. Large aggregation sites of shorebirds in Africa allow testing for the existence of AIV infection hot spots. We found that the processes whereby host ecology influence AIV transmission in wild birds in the Afrotropical context operate through ecologic factors (seasonal drying of wetlands and extended and nonsynchronized breeding periods) that are different than the one described in temperate regions, hence, resulting in different patterns of AIV infection dynamics.

  16. Serological and parasitological prevalence of Toxoplasma gondii in wild birds from Colorado.

    Science.gov (United States)

    Dubey, J P; Felix, T A; Kwok, O C H

    2010-10-01

    Ground-feeding birds are considered important in the epidemiology of Toxoplasma gondii because they serve as indicators of soil contamination by oocysts, and birds of prey are indicators of T. gondii prevalence in rodents and other small mammals. Cats excrete environmentally resistant oocysts after consuming tissues of T. gondii -infected birds. In the present study, sera and tissues from 382 wild birds from Colorado were tested for T. gondii infection. Antibodies to T. gondii were found in 38 birds with the use of the modified agglutination test (MAT, 1∶25 titer). Tissues (brains, hearts) of 84 birds were bioassayed in mice. Viable T. gondii was isolated from 1 of 1 barn owl (Tyto alba), 1 of 5 American kestrels (Falco sparverius), 1 of 7 ferruginous hawks (Buteo regalis), 1 of 4 rough-legged hawks (Buteo lagopus), 2 of 13 Swainson's hawks (Buteo swainsoni), and 1 of 25 red-tailed hawks (Buteo jamaicensis). This is the first time T. gondii has been isolated from the barn owl, ferruginous hawk, rough-legged hawk, and Swainson's hawk.

  17. From Dinosaurs to Birds:Puzzles Unraveled while Evidence Building up

    Institute of Scientific and Technical Information of China (English)

    CHEN Pingfu; SONG Jianlan

    2010-01-01

    @@ Rejuvenation of dinosaurian origin of birds and its theoretical difficulties In 1986,Prof.Jacques Gauthier from Yale University first applied cladistic systimatics to the analysis of the relationships between birds and other species in archosauria,a basal reptilian group that includes dinosaurs,pterosaurs,crocodilias and some other extinct reptilians.His analysis further confirmed that birds might have originated from a branch of small theropods close to Deinonychosauria.Encouraged by this work,the paleontological community cast intense attention to birds' dinosaurian origin theory,which was first presented by Thomas Henry Huxley over one century ago.Later on the discovery of feathered theropods in the Jehol Biota in 1996 offered much more robust evidence for this theory,and our understandings have since been significantly improved concerning how birds evolved from dinosaurs.Meanwhile,these exceptionally well-preserved specimens found in the Early Cretaceous strata of west Liaoning Province,China and its vicinity have also provided important information about the origins and early evolution of feathers and flight.

  18. Structural design principles of complex bird songs: a network-based approach.

    Directory of Open Access Journals (Sweden)

    Kazutoshi Sasahara

    Full Text Available Bird songs are acoustic communication signals primarily used in male-male aggression and in male-female attraction. These are often monotonous patterns composed of a few phrases, yet some birds have extremely complex songs with a large phrase repertoire, organized in non-random fashion with discernible patterns. Since structure is typically associated with function, the structures of complex bird songs provide important clues to the evolution of animal communication systems. Here we propose an efficient network-based approach to explore structural design principles of complex bird songs, in which the song networks--transition relationships among different phrases and the related structural measures--are employed. We demonstrate how this approach works with an example using California Thrasher songs, which are sequences of highly varied phrases delivered in succession over several minutes. These songs display two distinct features: a large phrase repertoire with a 'small-world' architecture, in which subsets of phrases are highly grouped and linked with a short average path length; and a balanced transition diversity amongst phrases, in which deterministic and non-deterministic transition patterns are moderately mixed. We explore the robustness of this approach with variations in sample size and the amount of noise. Our approach enables a more quantitative study of global and local structural properties of complex bird songs than has been possible to date.

  19. Structural design principles of complex bird songs: a network-based approach.

    Science.gov (United States)

    Sasahara, Kazutoshi; Cody, Martin L; Cohen, David; Taylor, Charles E

    2012-01-01

    Bird songs are acoustic communication signals primarily used in male-male aggression and in male-female attraction. These are often monotonous patterns composed of a few phrases, yet some birds have extremely complex songs with a large phrase repertoire, organized in non-random fashion with discernible patterns. Since structure is typically associated with function, the structures of complex bird songs provide important clues to the evolution of animal communication systems. Here we propose an efficient network-based approach to explore structural design principles of complex bird songs, in which the song networks--transition relationships among different phrases and the related structural measures--are employed. We demonstrate how this approach works with an example using California Thrasher songs, which are sequences of highly varied phrases delivered in succession over several minutes. These songs display two distinct features: a large phrase repertoire with a 'small-world' architecture, in which subsets of phrases are highly grouped and linked with a short average path length; and a balanced transition diversity amongst phrases, in which deterministic and non-deterministic transition patterns are moderately mixed. We explore the robustness of this approach with variations in sample size and the amount of noise. Our approach enables a more quantitative study of global and local structural properties of complex bird songs than has been possible to date.

  20. Evolution of the mammalian lysozyme gene family

    Directory of Open Access Journals (Sweden)

    Biegel Jason M

    2011-06-01

    Full Text Available Abstract Background Lysozyme c (chicken-type lysozyme has an important role in host defense, and has been extensively studied as a model in molecular biology, enzymology, protein chemistry, and crystallography. Traditionally, lysozyme c has been considered to be part of a small family that includes genes for two other proteins, lactalbumin, which is found only in mammals, and calcium-binding lysozyme, which is found in only a few species of birds and mammals. More recently, additional testes-expressed members of this family have been identified in human and mouse, suggesting that the mammalian lysozyme gene family is larger than previously known. Results Here we characterize the extent and diversity of the lysozyme gene family in the genomes of phylogenetically diverse mammals, and show that this family contains at least eight different genes that likely duplicated prior to the diversification of extant mammals. These duplicated genes have largely been maintained, both in intron-exon structure and in genomic context, throughout mammalian evolution. Conclusions The mammalian lysozyme gene family is much larger than previously appreciated and consists of at least eight distinct genes scattered around the genome. Since the lysozyme c and lactalbumin proteins have acquired very different functions during evolution, it is likely that many of the other members of the lysozyme-like family will also have diverse and unexpected biological properties.