Thermoregulatory abilities in chicks of the Antarctic Petrel (Thalassoica antarctica)

Summary We studied the thermoregulatory capacity of Antarctic Petrel chicks, Thalassoica antarctica, breeding in a large colony in Queen Maud Land (71°53S,5°10E) on the Antarctic continent. Compared to newly hatched chicks of other birds, those of the Antarctic Petrel are characterized by a relatively high standard metabolic rate (SMR) and thermal conductance. Their metabolic scope is limited, however, being only 1.6 times the SMR, and they consequently depend on parental brooding to maintain T_b. At an age of 11 days the chicks become thermally independent and are left alone in the nest. The chicks keep a relatively high body temperature (>36°C) throughout their early development and we found no indication that they normally experience hypothermia. A significant positive relationship between latitude of breeding and SMR of the hatchlings is shown to exist for procellariiform birds. It is suggested that the high SMR found in Antarctic Petrel hatchlings could be a prerequisite for achieving a high growth rate, rather than being of any thermoregulatory significance.Publication no. 105 from the Norwegian Antarctic Research Expeditions (1984/1985)