منابع مشابه
Effects of ACTH, capture, and short term confinement on glucocorticoid concentrations in harlequin ducks (Histrionicus histrionicus).
Little is known about baseline concentrations of adrenal hormones and hormonal responses to stress in sea ducks, although significant population declines documented in several species suggest that sea ducks are exposed to increased levels of environmental stress. Such declines have been observed in geographically distinct harlequin duck populations. We performed an adrenocorticotropic hormone (...
متن کاملWinter Philopatry of Harlequin Ducks in Prince William Sound, Alaska
We used capture-mark-recapture data to assess winter philopatry by Harlequin Ducks (Histrionicus histrionicus) in Prince William Sound, Alaska, during winters 1995–1997 and 2000–2001. Philopatry was quantified using homing rates, which were estimated as the proportion of birds recaptured at their original site out of all recaptured birds. Between-year homing rates of 0.95 (95% CI: 0.87–1.00) an...
متن کاملSurvival of Female Harlequin Ducks During Wing Molt
Survival rates of waterfowl during wing molt have rarely been described, leading to uncertainty about the importance of this annual cycle stage for management. We quantified survival probability of 247 radiomarked female harlequin ducks (Histrionicus histrionicus) during wing molt in Prince William Sound, Alaska, USA. The daily survival rate (DSR) was extremely high (DSR 1⁄4 0.999; 95% CI: 0.99...
متن کاملFish and harlequin ducks compete on breeding streams
We investigated interactions among harlequin ducks (Histrionicus histrionicus (L., 1758)), fish, and their shared aquatic insect prey. We measured flow variability, benthic aquatic prey abundance, fish presence, and breeding density of harlequins on eight rivers in the Southern Coast Mountain Range in British Columbia, Canada, in 2003 and 2004. Rivers with lower flow variability had higher abun...
متن کاملthe effects of keyword and context methods on pronunciation and receptive/ productive vocabulary of low-intermediate iranian efl learners: short-term and long-term memory in focus
از گذشته تا کنون، تحقیقات بسیاری صورت گرفته است که همگی به گونه ای بر مثمر ثمر بودن استفاده از استراتژی های یادگیری لغت در یک زبان بیگانه اذعان داشته اند. این تحقیق به بررسی تاثیر دو روش مختلف آموزش واژگان انگلیسی (کلیدی و بافتی) بر تلفظ و دانش لغوی فراگیران ایرانی زیر متوسط زبان انگلیسی و بر ماندگاری آن در حافظه می پردازد. به این منظور، تعداد شصت نفر از زبان آموزان ایرانی هشت تا چهارده ساله با...
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ژورنال
عنوان ژورنال: The Condor
سال: 2000
ISSN: 0010-5422
DOI: 10.1650/0010-5422(2000)102[0201:ltpbih]2.0.co;2