Pup production and distribution of breeding Antarctic fur seals ( Arctocephalus gazella) at South Georgia

• Published in: Antarctic Science
• Main Author: Boyd, I. L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1993
• Subjects: Antarc*; Antarctic; Antarctic Fur Seals; Antarctic Science; Arctocephalus gazella
• Online Access: http://dx.doi.org/10.1017/s0954102093000045; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102093000045

A census of the breeding population of Antarctic fur seals ( Arctocephalus gazella ) at South Georgia was carried out during the 1990/91 breeding season. Using counts of adult females ashore at the breeding grounds during the pupping period, together with corrections for the likelihood of a female being ashore at a census and for pregnancy rate (71% in 1990/91), pup production was estimated as 269 000 (95% confidence intervals 188 000-350000). The breeding population in 1990/91 was reduced at long-term study sites probably because of limited food availability. Data from these sites were used to estimate the pup production of the population had 1990/91 been a typical year. Based on values from 1983/84 to 1990/91, pup production in 1990/91 would have been 378000 (se=19100) if it had been an average year. The annual increase in pup production from 1976/77 to 1990/91 has declined to 9.8% since the initial period of population expansion in the 1950s and 1960s. Increased population size has led to an expansion of the breeding range at South Georgia.