THE FOOD AND ENERGY-INTAKE RATES OF ADULT EMPEROR PENGUINS (APTENODYTES FORSTERI) REARING CHICKS

The food and energy requirements of adult emperor penguins parenting c hicks were examined at Auster (about 11 000 pairs) and Taylor Glacier (about 2900 pairs) colonies during the winter, spring and summer of 19 88. Tritiated water-derived estimates of food consumption trebled duri ng the five-month period of chick care, ranging from 2.3 kg d(-1) in w inter when chicks were <5% of adult mass, to 6.3 kg d(-1) in summer, w hen chicks represented 40-50% of adult mass. These food consumption ra tes were equivalent to the acquisition of 11.4 MJ d(-1) and 33.4 MJ d( -1) metabolizable energy in winter and summer respectively. Chick prov isioning was not accompanied by a major increase in food consumption b y adults. Adults assimilated 84-92% of their daily food intake themsel ves and retained the remainder for the chick. The food ration of chick for the three seasons (42 kg) constituted only about 9.5% of adult ma intenance requirements during the same period. Adults consumed an esti mated 482 kg of food (including the ration for the chick), which amoun ted to about 10 700 t and 2800 t of fish and squid consumed by the bre eding populations at Auster and Taylor Glacier, respectively.