The New Zealand fur seal, Arctocephalus Forsteri (Lesson), at Macquarie Island, 1949-64

Abstract

The indigenous fur seal at Macquarie I. was exterminated between 1810 and 1820. Between 1919 and 1948 the New Zealand fur seal, breeding on islands to the north-east, began to visit the island in summer. ANARE observers have reported that the maximum number in the original area colonized has increased from 174 in 1950 to 474 in 1963, at least three other localities now have regular summer populations, and a few seals remain throughout the winter. Several pups have been born since 1955. The summer visitors include immatures of both sexes, adult males, and a few non-breeding adult females; the winter residents are older immatures and adult males. Most of the seals arrive in December-January, which is the breeding season and also the period of most easily available food; they leave during April-May, when the Eudyptes penguins, an important food source, also depart. Thus, the later stages of weaning, up to August by analogy with this species in New Zealand, may be a difficult period at Macquarie I., and availability of food for the pups during June-August may determine the breeding success and future population size there.