Juvenile survival and recruitment in a population of Weddell seals ( Leptonychotes weddellii ) in McMurdo Sound, Antarctica

• Published in: Canadian Journal of Zoology
• Main Author: Testa, J. Ward
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1987
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; McMurdo Sound; Weddell; Erebus Bay; Antarc*; Antarctica; Weddell Seal; Weddell Seals
• Online Access: http://dx.doi.org/10.1139/z87-453; http://www.nrcresearchpress.com/doi/pdf/10.1139/z87-453

Survival and recruitment of Weddell seal pups were studied in eastern McMurdo Sound, Antarctica. Pups were marked and their apparent survival estimated by mark–recapture methods. The resulting estimates were used together with published estimates of adult survival, yearly sighting probabilities, and direct counts of pup production to simulate the dynamics of the population and evaluate the assumption that it is closed to immigration. Estimates derived from census data in 1982 and 1983 were over five times larger than those simulated. This discrepancy was due to the extremely low juvenile survival rates calculated from marked seals. Since few animals born in Erebus Bay return to breed, the large adult breeding population must be the result of substantial immigration, indicating an important role for juvenile dispersal in the population dynamics of Weddell seals.