Decline of Spectacled Eiders Nesting in Western Alaska
ABSTRACT. Spectacled eider (Somareria jischeri) populations in western Alaska are now less than 4 % of the numbers estimated in the early 1970s. In 1992, an estimated 1721 nesting pairs remained on the Yukon-Kuskokwim Delta. Causes of this rapid and continuing decline of-14 % per year are undocument...
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| Format: | Text |
| Language: | English |
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1993
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.522.485 http://pubs.aina.ucalgary.ca/arctic/arctic46-3-264.pdf |
| Summary: | ABSTRACT. Spectacled eider (Somareria jischeri) populations in western Alaska are now less than 4 % of the numbers estimated in the early 1970s. In 1992, an estimated 1721 nesting pairs remained on the Yukon-Kuskokwim Delta. Causes of this rapid and continuing decline of-14 % per year are undocumented. Many aspects of spectacled eider biology remain unknown, including their marine foraging habitats, food items, migratory movements, and population ecology. A review of some biological characteristics and possible threats to the species suggests the importance of quantifying potential impacts from parasites and disease, subsistence harvest, predation during brood rearing, and alteration of Bering Sea food resources. Factors causing the population decline of spectacled eiders must be determined and appropriate actions taken to reverse the trend. Key words: Alaska, declining species, Somateria fmheri, spectacled eider, waterfowl, Yukon-Kuskokwim Delta RfiSUMfi. Les populations d’eiders B lunettes (Somateria jischeri) de l’Alaska occidental s’6lbvent maintenant B moins de 4 p. cent du total estime au debut des a n n k s 70. En 1992, on a estime B 1721 le nombre de paires nicheuses qui restaient dans le delta du Yukon-Kuskokwim. Les causes de ce declin rapide et continu de-14 p. cent par an ne sont pas documentees. Bien des aspects de la biologie de l’eider B lunettes restent inconnus, y compris l’habitat marin oh il trouve sa nourriture, ses aliments, ses dkplacements migratoires et l’kologie de la population. Un examen de certaines caracteristiques biologiques et des menaces dont l’espkce pourrait faire l’objet suggbre l’importance qu’il y a B quantifier les retombees potentielles des parasites et des maladies, des rkcoltes destin & il assurer la subsistance, de la predation durant l’blevage de la couvee et des changements dans les ressources alimentaires de la mer de Bering. I1 faut determiner les facteurs responsables |
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