نتایج جستجو برای: feathers
تعداد نتایج: 2568 فیلتر نتایج به سال:
To the Editor: Free-range domestic ducks can be a key factor in regional spreading of Asian subtype H5N1 avian infl uenza (AI) virus (1–3). Even asymptomatic domestic ducks can shed the virus continuously from the oral cavity and cloaca (3–5). Therefore, early detection of infected ducks that are shedding the virus would reduce the risk of spreading AI virus (H5N1) in a region where the virus h...
Genetic analysis of noninvasively collected bird feathers is of growing importance to avian ecology; however, most genetic studies that utilize feathers make no mention of the need to verify their species of origin. While plumage patterns and collection location often are indicative of species identity, broad-scale feather collections may require definitive species identification prior to analy...
Plumage coloration in birds plays a critical role in communication and can be under selection throughout the annual cycle as a sexual and social signal. However, for migratory birds, little is known about the acquisition and maintenance of colorful plumage during the nonbreeding period. Winter habitat could influence the quality of colorful plumage, ultimately carrying over to influence sexual ...
Mercury concentrations were measured in feathers oflittle egret and night heron chicks and in their prey in the Axios Delta,Greece. Significantly higher concentrations occurred in night heron than inlittle egret in 1993. In the night heron the mercury content of feathers wasnegatively correlated to the size of chicks, possibly due to inhibition ofgrowth. Mercury concentrations were higher than ...
In the two decades since the discovery of feathered dinosaurs [1-3], the range of plumage known from non-avialan theropods has expanded significantly, confirming several features predicted by developmentally informed models of feather evolution [4-10]. However, three-dimensional feather morphology and evolutionary patterns remain difficult to interpret, due to compression in sedimentary rocks [...
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