Pup production and distribution of breeding Antarctic fur seals (Arctocephalus gazella) at South Georgia
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 bei...
| Published in: | Antarctic Science |
|---|---|
| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
Cambridge University Press
1993
|
| Subjects: | |
| Online Access: | http://nora.nerc.ac.uk/id/eprint/517594/ https://doi.org/10.1017/S0954102093000045 |
| Summary: | 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. |
|---|