BODY SIZE VARIATION IN LESSER SNOW GEESE - ENVIRONMENTAL PLASTICITY IN GOSLING GROWTH-RATES

We examined the influence of timing of reproduction and brood size on growth rates of goslings of nidifugous Lesser Snow Geese (Anser caerulescens caerulescens) using data collected at La Perouse Bay, Manitoba from 1978 to the present. Gosling growth rates declined significantly during the season, and the declines were independent of the parental genotype. Goslings from larger broods grew significantly faster, but there was no significant annual variation in the seasonal growth rate patterns with either hatch date or brood size. The hatch date and brood size effects could not be accounted for by systematic differences in either egg size or body size of the female parent. Goslings that grew more slowly due to the effects of hatch date or brood size were significantly smaller as adults. Because gosling growth rates influence final adult size, they may have a significant effect on various life history traits in this species.