Interspecific and intraspecific differences in the diets of Fur seals, Arctocephalus species (Pinnipedia: Otariidae) at Macquarie Island.

Abstract

Between November 1988 and March 1989, scats were collected from three species of fur seals (Arctocephalus forsteri, A. gazella and A. tropicalis) at the northern end of Macquarie Island and from A. forsteri between January and March 1989 at the southern end. All fed mainly on fish. For A. gazella/A. tropicalis an average 99.2 % of scats in monthly collections contained fish remains, while for A. forsteri the figure for North Head was 100 % and for Hurd Point was 94.9 %. Arctocephalus forsteri at Hurd Point took less fish and more penguins than at North Head and there were significant differences in the composition of the fish diet in two of three months. At North Head, the fish diet of A. gazella/A. tropicalis differed significantly from that of A. forsteri in three of the five months studied . Food resources for fur seals around Macquarie Island are considered to be less available than they are around Heard Island.