Seasonal and Geographical Variation in the Food of Weddell Seals, Leptonychotes-Weddelii, in Antarctica

Abstract

The food of Weddell seals was investigated between 1983 and 1985 at Davis, Mawson and McMurdo Sound. Food samples were obtained from stomach samples, vomitus and faeces. Fish remains predominated in samples at all three sites. At Davis, prawn (decapod crustacean) remains were more common than those of cephalopods, the reverse of the situation at Mawson and McMurdo Sound. The differences between sites probably reflects different physical characteristics, especially with regard to local sea depth. In faeces collections over 13 months in the Davis region the food taken differed both seasonally and locally: prawn remains predominated in inshore areas, and fish offshore; prawn remains predominated overall between January and April, but fish predominated from then until December. Cephalopod remains were less common at Davis than reported hitherto for Weddell seals, and octopus remains were more common than those of squid. The seasonal changes in food types at Davis reflected the movement of seals from shallow inshore waters during spring and summer to deeper offshore waters with the advance of the sea ice in winter.