ARCTIC The Numbers and Distribution of Greater Snow Geese on Bylot Island and near

ABSTRACT. We conducted aerial photographic surveys of greater snow geese on portions of Bylot Island and northern Baffin Island during August 1988 to determine whether changes had occurred since a similar survey in 1983. On the 1600 km ’ south plain of Bylot Island, using a quadrat system and stratified random sampling, we estimated a population of 26 300 breeding adults, 5400 failed-\and non-breeding adults, and 41 400 goslings; the breeding component had increased by 58 % from the 1983 survey. In a 274 km ’ study area in Jungersen Bay on northern Baffin Island, we conducted total counts and recorded 2555 adult breeders, 546 failed- and non-breeders, and 4127 goslings; the, breeding segment had declined by 15 % since 1983. The later date of the survey in 1988, relative to that of 1983, is believed to have been the main cause of a more even distribution of broods among strata on Bylot Island and may have contributed to an underestimation of breeding geese at Jungersen Bay. Both survey areas supported high densities of breeding greater snow geese in both years. Bylot Island supported a similar proportion of the entire greater snow goose breeding popula-tion in 1988 (13%) and 1983 (15%). Key words: Anser caerulescens atlanticus, Baffin Island, breeding distribution, Bylot Island, Canada, goose surveys, greater snow goos