Moulting starvation in emperor penguin (Aptenodytes forsten) chicks

The moult fast in emperor penguin (Aptenodytes forsteri) chicks was studied during January 1990 at Drescher Inlet, eastern Weddell Sea. In early January feeding of the chicks had stopped and about 4,000–5,000 chicks were in the inlet. The number of starving chicks decreased rapidly until 26 January when all chicks had either left the inlet or died. Mean body mass loss of starving chicks was 257 g/day and the evaluated specific daily mass loss was 25 g/kg body mass. The critical body mass, i.e. the mass below which chicks die, during moulting starvation was estimated to be 4 kg. Mean body mass was higher and mass loss lower in chicks at more advanced moult stages. Chicks left the inlet before moult was completed, although the sea-ice was still stable.