New Zealand fur seals at the Bounty Islands

Abstract

Abstract New Zealand fur seals, Arctocephalus forsteri (Lesson, 1828), at the Bounty Islands (47°45'S, 179°03'E) were virtually annihilated by commercial sealing in the period 1808–1890. Legal protection and the cessation of sealing in 1891 were followed by a slow increase in numbers. Aerial photography is a practical method for monitoring fur seal numbers at the Bounty Islands, where the animals show up clearly on the smooth granite substrate. Low‐level oblique aerial photographs taken between May 1974 and December 1980 have been used to determine the present distribution of seal colonies and estimate the numbers ashore. The number of seals (excluding new‐born pups) ashore on 29 December 1980 was estimated as 6700, and the number of pups as 3280, from sample counts of 3050 and 477 respectively. Calculations based on estimated pup production, and published figures on immature mortality, sex ratio, and pregnancy rate from other fur seal populations, suggest that the total population of the Bounty Islands i...