Comparison of best candidate models for predicting prevalence of antibodies to avian influenza viruses in four different species of geese on the Yukon-Kuskokwim Delta, Alaska, 2009–2010.

Models with the lowest AIC values had the best fit. (Not all model results given for Social Index and Winter Habitat Use due to poor model fit).1Emperor geese winter in the Aleutian Islands and Alaska Peninsula, black brant on the Pacific Coast from British Columbia to Mexico, and cackling geese and greater white-fronted geese co-occur in interior valleys of Washington, Oregon, and California.2Cackling geese, greater white-fronted geese, and black brant (the latter with rare exception), spend their entire life cycle within the western hemisphere, whereas emperor geese are endemic to Alaska and the Bering Sea region and spend part of their life cycle in Asia.3Proportion of birds infected with AI viruses in spring (see Methods).4Black brant are colonial nesting while the other species are dispersed nesters.5Black brant and emperor geese winter in coastal marine environments, whereas cackling geese and greater white-fronted geese use agricultural areas.