EFFECTS OF SUMMER FEEDING AREA ON GOSLING GROWTH IN SNOW GEESE

Relative growth of body parts (wing, culmen, tarsus) in young Snow Geese differed among years and among summer feeding areas only a few kilometers apart in the vicinity of the McConnell River, Northwest Territories, Canada. Gosling age was unknown at time of capture, so we expressed all differences in measured characteristics as a function of culmen length. This procedure may underestimate the magnitude of differences in growth with respect to age. Year and summer feeding area had large, independent effects on relative growth. Growth of primary feathers showed the greatest variation of measurable variables among feeding areas. We argue that the cause of most differences in relative growth was nutritional variation of vegetation. If goslings with retarded growth do not entirely catch up on fall staging areas, there may be lasting demographic effects.