Antarctic fur seal predator performance indices for the South Shetland Islands 1987/88–2002/03

Fifteen predator performance indices for Antarctic fur seals breeding at two sites in the South Shetland Islands are presented. Five indices were derived from CEMP standard methods C1 (female foraging trip duration) and C2b (pup growth rates). Measures of female foraging trip duration, pup growth rates, adult female survival and natality were made at Seal Island from 1986/87-1994/95. Studies at Cape Shirreff, Livingston Island measured female foraging trip duration, foraging range, diet (3), pup growth rates (3), pup mortality, timing of reproduction, adult female survival and natality, cohort success, pup production, and the change in pup production from 1997/98 through 2002/03. Pup growth rate (C2b) data were recalculated for 1997/98-2001/02 to facilitate comparisons between sites. Long foraging trip durations (7.09d ±0.19), below average frequency of krill in fur seal diet (79.6% ±7.7), above average pup mortality (9.0%), decrease pup production (-12.1%), and below average adult female survival (85.8%) and natality (74.3%) all indicated that 2002/03 was a season of poor reproductive performance for fur seals at Cape Shirreff.