BREEDING ENERGETICS AND FOOD-REQUIREMENTS OF GENTOO PENGUINS (PYGOSCELIS-PAPUA) AT HEARD AND MACQUARIE ISLANDS

The food and energy requirements of breeding gentoo penguins (Pygoscel is papua) were studied at Heard and Macquarie Islands by means of isot ope turnover techniques. The food consumption rates of chicks were mea sured at various stages of growth, providing estimates of the total fo od provided by adults to rear a chick to fledging. The energy expendit ures of attending adults were also measured at different stages of chi ck-rearing, allowing the total energy costs associated with breeding t o be established for a pair of adults and at the population level on b oth islands. We estimate the total annual energy budget of a 6.2 kg br eeding gentoo penguin to be 1517 MJ which is equivalent to the consump tion of 292 kg prey.