Correlated growth and survival of juvenile spectacled eiders: Evidence of habitat limitation?

The Condor
By: , and 



We studied the growth and survival of Spectacled Eider (Somateria fischeri) ducklings to 30 days of age along the lower Kashunuk River on the Yukon-Kuskokwim Delta from 1995 to 2000. We replicated this study at a second site, Kigigak Island, in 1999 and 2000. Age-adjusted estimates of duckling mass and survival at 30 days posthatching were highly variable. Duckling survival was consistently higher on Kigigak Island in 1999 and 2000, averaging 67%, while survival on the Kashunuk River averaged 45% during the same time period. Duckling survival was negatively related to hatching date. At the Kashunuk River site our data supported models that indicated age-adjusted mass varied with habitat type and declined with hatching date. Ducklings from Kashunuk River were heavier in 1999, while ducklings from Kigigak Island were heavier in 2000. However, we found a positive correlation between 30-day duckling survival and age-adjusted mass, suggesting a localized environmental effect on both parameters. We conclude that predation may be the proximate mechanism of mortality, but habitat conditions are likely the ultimate factors influencing duckling survival. Geographic variation in rates of duckling survival and apparent growth suggest that spatial heterogeneity in population vital rates is occurring at multiple levels.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Correlated growth and survival of juvenile spectacled eiders: Evidence of habitat limitation?
Series title The Condor
DOI 10.1650/0010-5422(2006)108[901:CGASOJ]2.0.CO;2
Volume 108
Issue 4
Year Published 2006
Language English
Publisher Cooper Ornithological Society
Contributing office(s) Alaska Science Center, Alaska Science Center Biology WTEB, Coop Res Unit Atlanta
Description 11 p.
First page 901
Last page 911
Country United States
State Alaska
Other Geospatial Yukon-Kuskokwim Delta
Online Only (Y/N) N
Additional Online Files (Y/N) N
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