Growth of the snow goose, Chen caerulescens , colony at McConnell River, Northwest Territories: 1940-1980

The McConnell River Snow Goose (Chen caerulescens ) colony apparently was established in the early part of this century. Historical population estimates and recent counts from aerial photographs showed very rapid growth, from about 7000 nesting pairs in 1941 to 163,000 in 1973, levelling off thereafter. Local reproduction cannot account for the rapid growth, and both immigration and emigration are thought to have occurred. Feeding in croplands during migration and improved habitat in winter may have led to greater survival and perhaps to larger numbers of non-breeders on increasingly crowded nesting areas. This overcrowding, combined with unfavorable conditions as in a late spring, might help the birds overcome their normal site tenacity to make a mass relocation.