PHYSIOLOGICAL-RESPONSES OF COLD-STRESSED BLUE AND SNOW PHASE LESSER SNOW GOOSE GOSLINGS

A comparison of cold-stressed Lesser Snow Goose (Chen caerulescens caerulescens) goslings revealed that the metabolic rates of light-colored (snow) and dark-colored (blue) goslings did not differ when they were measured in the dark. Small differences in plumage insulation (higher in snow goslings) and core body temperature (lower in blue goslings) seemed to balance each other so that there was no difference in rates of thermogenesis between morphs. We conclude that physiological thermoregulation does not compensate for potential differential radiative heat loads between the morphs.