1,351 research outputs found

    Thyroid hormones correlate with resting metabolic rate, not daily energy expenditure, in two charadriiform seabirds

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    K. Woo, M. Le Vaillant, T. van Nus, and especially A. Wesphal, J. Schultner and I. Dorresteijn, assisted with field work, often under unpleasant conditions. K. Wauthier was instrumental in wrestling the gamma counter into submission. P. Redman and C. Hambly conducted the isotopic analyses. K. Scott and K. Campbell provided the FoxBox. K.H.E. benefited from a Natural Sciences and Engineering Research Council (NSERC) Vanier Scholarship, Association of Canadian Universities for Northern Studies Garfield Weston Northern Studies Award and the Arctic Institute of North America Jennifer Robinson Scholarship. Research support came from Bird Studies Canada/Society of Canadian Ornithologists James Baillie Award, Animal Behavior Society Research Grant, American Ornithologists’ Union Research Grant, Frank Chapman Research Grant, the Waterbird Society Nisbet Grant and NSERC Discovery Grants to J.F.H. and W.G.A. Any use of trade names is for descriptive purposes only and does not imply endorsement by the US Government.Peer reviewedPublisher PD

    Counting calories in cormorants : dynamic body acceleration predicts daily energy expenditure measured in pelagic cormorants

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    The doubly-labelled water assays and accelerometers were paid for by the authors. Funding to reach Middleton Island was supported through the Animal Behaviour Society Research Grant and the Northern Scientific Training Program of Indigenous and Northern Affairs Canada.Peer reviewedPublisher PD

    Behavioral and physiological responses to male handicap in chick-rearing black-legged kittiwakes

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    Parental investment entails a trade-off between the benefits of effort in current offspring and the costs to future reproduction. Long-lived species are predicted to be reluctant to increase parental effort to avoid affecting their survival. We tested this hypothesis in black-legged kittiwakes Rissa tridactyla by clipping flight feathers of experimental males at the beginning of the chick-rearing period. We analyzed the consequences of this handicap on feeding and attendance behavior, body condition, integument coloration, and circulating levels of corticosterone and prolactin in handicapped males and their mates in comparison to unmanipulated controls. Chicks in both groups were compared in terms of aggressive behavior, growth, and mortality. Handicapped males lost more mass, had less bright integuments, and attended the nest less often than controls. Nevertheless, they fed their chicks at the same rate and had similar corticosterone and prolactin levels. Compared with control females, females mated with handicapped males showed a lower provisioning rate and higher nest attendance in the first days after manipulation. Their lower feeding rate probably triggered the increased sibling aggression and mortality observed in experimental broods. Our findings suggest that experimental females adaptively adjusted their effort to their mate's perceived quality or that their provisioning was constrained by their higher nest attendance. Overall, our results suggest that kittiwake males can decrease their condition for the sake of their chicks, which seems to contradict the hypothesis that kittiwakes should be reluctant to increase parental effort to avoid affecting their surviva

    Evidence that pairing with genetically similar mates is maladaptive in a monogamous bird

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    <p>Abstract</p> <p>Background</p> <p>Evidence of multiple genetic criteria of mate choice is accumulating in numerous taxa. In many species, females have been shown to pair with genetically dissimilar mates or with extra-pair partners that are more genetically compatible than their social mates, thereby increasing their offsprings' heterozygosity which often correlates with offspring fitness. While most studies have focused on genetically promiscuous species, few studies have addressed genetically monogamous species, in which mate choice tends to be mutual.</p> <p>Results</p> <p>Here, we used microsatellite markers to assess individual global heterozygosity and genetic similarity of pairs in a socially and genetically monogamous seabird, the black-legged kittiwake <it>Rissa tridactyla</it>. We found that pairs were more genetically dissimilar than expected by chance. We also identified fitness costs of breeding with genetically similar partners: (i) genetic similarity of pairs was negatively correlated with the number of chicks hatched, and (ii) offspring heterozygosity was positively correlated with growth rate and survival.</p> <p>Conclusion</p> <p>These findings provide evidence that breeders in a genetically monogamous species may avoid the fitness costs of reproducing with a genetically similar mate. In such species that lack the opportunity to obtain extra-pair fertilizations, mate choice may therefore be under high selective pressure.</p

    Ecological Modeling of Aedes aegypti (L.) Pupal Production in Rural Kamphaeng Phet, Thailand

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    Background - Aedes aegypti (L.) is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites. Methodology - Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts. Findings - The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types increased significantly as habitat density increased. An ecological approach, accounting for development site density, is appropriate for predicting Ae. aegypti population levels and developing efficient vector control program

    Windscapes shape seabird instantaneous energy costs but adult behavior buffers impact on offspring

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    Acknowledgements K. Ashbrook, M. Barrueto, K. Elner, A. Hargreaves, S. Jacobs, G. Lancton, M. LeVaillant, E. Grosbellet, A. Moody, A. Ronston, J. Provencher, P. Smith, K. Woo and P. Woodward helped in the field. J. Nakoolak kept us safe from bears. N. Sapir and two anonymous reviewers provided very useful comments on an earlier version of our manuscript. R. Armstrong at the Nunavut Research Institute, M. Mallory at the Canadian Wildlife Service Northern Research Division and C. Eberl at National Wildlife Research Centre in Ottawa provided logistical support. F. Crenner, N. Chatelain and M. Brucker customized the GPS at the IPHC-CNRS. KHE received financial support through a NSERC Vanier Canada Graduate Scholarship, ACUNS Garfield Weston Northern Studies scholarship and AINA Jennifer Robinson Scholarship and JFH received NSERC Discovery Grant funding. J. Welcker generously loaned some accelerometers. All procedures were approved under the guidelines of the Canadian Council for Animal Care.Peer reviewedPublisher PD

    USU Teaching Documentation: Dossiers from the Mentoring Program

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    The nation\u27s land grant institutions were founded on the principle of access for the general public to the knowledge gained through research and creative activity fostered in higher education. Central to our access mission is our dedication to teaching and learning that is informed by research and discovery, both of which must result, at least in part, from our engagement with our external constituents. That teaching and learning informs our research and vice versa; our research informs and aids in our teaching mission. This work, compiled by Professors Maria Luisa Spicer-Escalante and Cathy Ferrand Bullock, is focused on how the best, highly informed teaching is accomplished when done in an intentional manner. That intentional process helps the best university educators thoughtfully build their teaching story in an organized manner. Educators think about how they can successfully reach and engage their appropriate student audiences (or mentees), what they hope to accomplish, and how they intend to accomplish their goals. Further, as learning outcomes are identified and established, first-rate methods for course design, content inclusion, and continuous improvement can be outlined. Those of us who follow these intentional principles may then detail our growth and success along the way as teachers in the development of documents that tell our stories. Undoubtedly, the ability to clearly document and articulate that story will help academic personnel add to their tenure and promotion preparation in a very meaningful way. But as or even more important is the opportunity to describe these journeys with all the efforts, large and small, of improving their product in terms of learning outcomes and student growth and success. The nuggets of wisdom compiled by Professors Spicer-Escalante and Bullock, in USU Teaching Documentation: Dossiers from the Mentoring Program, will help teachers across the board from the new lecturer or assistant professor to the experienced professor dive into their teaching programs and find ways to continuously experiment and refine their approaches to our critically important student audiences. Good luck, teach on, and successfully document some of the most important work you all do! Frank Galey Executive Vice President and Provost Utah State University 2019https://digitalcommons.usu.edu/ua_faculty/1000/thumbnail.jp
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