Body temperature and resting behavior of Greater Snow Goose goslings in the high Arctic

We examined the control of body temperature during active and resting behav iors in chicks of a large precocial bird, the Greater Snow Goose (Chen caer ulescens atlantica), growing in a cold Arctic environment. Imprinted goslin gs from 4 to 31 days old maintained their mean (+/- SD) body core temperatu re within a narrow range around 40.6 +/- 0.2 degrees C (range: 38.7-42.2 de grees C), independently of changes in their thermal environment. Average bo dy temperature increased <0.4 degrees C between 4 and 31 days of age. Hypot hermia, potentially an energy-saving mechanism, was not used by active gosl ings. The potential for hear loss to the environment influenced the length of resting bouts in wild goslings. As environmental temperature increased, wild goslings remained sitting alone for longer periods, whereas when it de creased, brooding behavior was prolonged. The time spent huddling increased with the number of goslings involved. Body temperature during huddling bou ts measured in imprinted chicks was significantly lower than during periods of activity, showing a rapid decrease averaging 0.8 degrees C at the onset of huddling, followed by a slow recovery before activity was resumed. Thus , huddling behavior was not used as a rewarming mechanism. Greater Snow Goo se goslings appear to prioritize metabolic activity by maintaining a high b ody temperature, despite the high energy costs that may be involved. Social thermoregulation is used to reduce the energy costs entailed by the strict maintenance of homeothermy.