Effects of gull predation and weather on survival of emperor goose goslings

Journal of Wildlife Management
By: , and 

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Abstract

Numbers of emperor geese (Chen canagica) have remained depressed since the mid-1980s. Despite increases in glaucous gulls (Larus hyperboreus), a primary predator of goslings, little information existed to assess whether recent patterns of gosling survival have been a major factor affecting population dynamics. We used observations of known families of emperor geese to estimate rates of gosling survival during 1993-96 on the Yukon-Kuskokwim Delta, Alaska. Survival of goslings to 30 days of age varied among years from 0.332 during 1994 to 0.708 during 1995. Survival was lowest during 1993-94, which corresponded with the years of highest frequency of disturbance of goose broods by glaucous gulls. Rainfall during early brood rearing was much higher in 1994 than other years, and this corresponded to low survival among goslings ≤5 days of age. Numbers of juveniles in families during fall staging were negatively related to rainfall during early brood rearing (n = 23 yr). Although there are no data to assess whether gosling survival in emperor geese has declined from some previous level, current survival rates of emperor goose goslings are as high as or higher than those observed in other goose species that are rapidly increasing. A proposed reduction of glaucous gull numbers by managers may not be the most effective means for increasing population growth in emperor geese.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Effects of gull predation and weather on survival of emperor goose goslings
Series title Journal of Wildlife Management
DOI 10.2307/3802904
Volume 65
Issue 2
Year Published 2001
Language English
Publisher Wiley
Contributing office(s) Alaska Science Center
Description 10 p.
First page 248
Last page 257
Country United States
State Alaska
Other Geospatial Yukon-Kuskokwim Delta