Food and feeding of sperm whales Physeter macrocephalus off the west coast of South Africa

Abstract

The stomach contents of 1 268 sperm whales Physeter macrocephalus processed at the Donkergat whaling station, South Africa, were examined during the 1962 and 1963 whaling seasons. Results were compared with Clarke's analysis of cephalopod beaks collected in 1963 (Clarke 1980). There was no significant difference in the incidence of food in the stomachs between whales taken in the morning (07:15–11:15), at midday (11:15–15:15) or in the afternoon (after 15:15). The incidence of food remains was less in medium-sized (12.2–13.7 m) and large (≥ 14 m) males than in small (≤ 11.9 m) males and females, and their stomachs more frequently contained the beaks of cephalopod species from the Antarctic or subAntarctic. These phenomena were related to a winter migration of medium-sized and large males into the whaling ground from south of the Subtropical Convergence. Medium-sized and large males fed more frequently on larger species of endemic cephalopods than females or small males, whereas males in general ate larger...