Summary

Description

The only known breeding population of the endangered Aleutian Canada goose Branta canadensis leucopareia was studied from 1974 to 1977 at Buldir Island, Alaska. Geese began arriving at Buldir in early May, and laying peaked during the last week of May or early June. Most eggs hatched in late June or early July, and goslings fledged by 21 August. Most geese left Buldir during September. Unlike many other populations of Canada geese, the Aleutian birds did not nest near water. Nest sites were on steep, densely vegetated slopes of the volcanic island, generally below 300 m elevation. Geese exhibited distinct preferences for certain plant communities. The effects of various habitat characteristics and proximity to predators on reproductive success of geese were evaluated. The nesting population of geese at Buldir was estimated with a stratified random sampling method, and observations of marked birds allowed determination of the age composition of the population. Reasons for observed population increases are discussed.