Winter Fidelity and Apparent Survival of Lesser Snow Goose Populations in the Pacific Flyway

• Published in: The Journal of wildlife management 2008-01, Vol.72 (1), p.159-167
• Main Authors: Williams, Christopher K, Samuel, Michael D, Baranyuk, Vasily V, Cooch, Evan G, Kraege, Don
• Format: Article
• Language: English
• Subjects: Animal breeding; Aquatic birds; Aviculture; Banks Island; Bird banding; Bird nesting; Birds; Breeding; Chen caerulescens; Chen caerulescens caerulescens; Emigration; Game and Nongame Birds; Geese; Male animals; MANAGEMENT AND CONSERVATION; mark-recapture; Metapopulations; migration; Pacific Flyway; Population; Population structure; recruitment; Snow; snow goose; Subpopulations; Survival; Waterfowl; Wildlife management; Wrangel Island
• ISSN: 0022-541X; 1937-2817
• DOI: 10.2193/2005-748

The Beringia region of the Arctic contains 2 colonies of lesser snow geese (Chen caerulescens caerulescens) breeding on Wrangel Island, Russia, and Banks Island, Canada, and wintering in North America. The Wrangel Island population is composed of 2 subpopulations from a sympatric breeding colony but separate wintering areas, whereas the Banks Island population shares a sympatric wintering area in California, USA, with one of the Wrangel Island subpopulations. The Wrangel Island colony represents the last major snow goose population in Russia and has fluctuated considerably since 1970, whereas the Banks Island population has more than doubled. The reasons for these changes are unclear, but hypotheses include independent population demographics (survival and recruitment) and immigration and emigration among breeding or wintering populations. These demographic and movement patterns have important ecological and management implications for understanding goose population structure, harvest of admixed populations, and gene flow among populations with separate breeding or wintering areas. From 1993 to 1996, we neckbanded molting birds at their breeding colonies and resighted birds on the wintering grounds. We used multistate mark–recapture models to evaluate apparent survival rates, resighting rates, winter fidelity, and potential exchange among these populations. We also compared the utility of face stain in Wrangel Island breeding geese as a predictor of their wintering area. Our results showed similar apparent survival rates between subpopulations of Wrangel Island snow geese and lower apparent survival, but higher emigration, for the Banks Island birds. Males had lower apparent survival than females, most likely due to differences in neckband loss. Transition between wintering areas was low (