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Population dynamics of long-tailed ducks breeding on the Yukon-Kuskokwim Delta, Alaska

Arctic

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Abstract

Population estimates for long-tailed ducks in North America have declined by nearly 50% over the past 30 years. Life history and population dynamics of this species are difficult to ascertain, because the birds nest at low densities across a broad range of habitat types. Between 1991 and 2004, we collected information on productivity and survival of long-tailed ducks at three locations on the Yukon-Kuskokwim Delta. Clutch size averaged 7.1 eggs, and nesting success averaged 30%. Duckling survival to 30 days old averaged 10% but was highly variable among years, ranging from 0% to 25%. Apparent annual survival of adult females based on mark-recapture of nesting females was estimated at 74%. We combined these estimates of survival and productivity into a matrix-based population model, which predicted an annual population decline of 19%. Elasticities indicated that population growth rate (λ) was most sensitive to changes in adult female survival. Further, the relatively high sensitivity of λ to duckling survival suggests that low duckling survival may be a bottleneck to productivity in some years. These data represent the first attempt to synthesize a population model for this species. Although our analyses were hampered by the small sample sizes inherent in studying a dispersed nesting species, our model provides a basis for management actions and can be enhanced as additional data become available.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Population dynamics of long-tailed ducks breeding on the Yukon-Kuskokwim Delta, Alaska
Series title:
Arctic
Volume
62
Issue:
2
Year Published:
2009
Language:
English
Publisher:
Arctic Institute of North America
Publisher location:
Calgary, Alberta
Contributing office(s):
Alaska Science Center Biology WTEB
Description:
11 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Arctic
First page:
190
Last page:
200
Time Range Start:
1991-01-01
Time Range End:
2004-12-31
Country:
United States
Other Geospatial:
Yukon-kuskokwin Delta