Annual Survival and Site Fidelity of Steller's Eiders Molting along the Alaska Peninsula
| Autor: | James D. Nichols, Christian P. Dau, Paul L. Flint, Margaret R. Petersen, James E. Hines |
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| Rok vydání: | 2000 |
| Předmět: |
Muda
geography geography.geographical_feature_category Ecology biology Zoology biology.organism_classification Anatidae Population decline Peninsula Waterfowl General Earth and Planetary Sciences Philopatry Ecology Evolution Behavior and Systematics Overwintering Sex ratio Nature and Landscape Conservation General Environmental Science |
| Zdroj: | The Journal of Wildlife Management. 64:261 |
| ISSN: | 0022-541X |
| DOI: | 10.2307/3802998 |
| Popis: | Populations of Stellers eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have decliued since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilitics within and among lagoons for male and female eiders. Estimates of annual survival (±SE) were 0.899 = 0.032 for females and 0.765 = 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons: yet we found no evidence that aunual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have mitiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential. |
| Databáze: | OpenAIRE |
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