Fecundity, survival and site fidelity in Weddell seals, Leptonychotes weddelli

Age-specific fecundity data are presented for 17 yr of tagging and recapture of Leptonychotes weddelli at Signy Island, South Orkney Islands. Minimum age of first pupping was 2 yr, mean age was 4-5 yr, and among females recaptured at age 9 yr and over 94% were with pups. Mean annual survival of females at Signy that have pupped once was 0.80. Breeding cows are not distributed independently of the location of their previous breeding sites. There is no indication that pups tend to return to breed at their natal site. Weddell seal and crabeater seal Lobodon carcinophagus population parameters are contrasted, and although diet may be important in establishing some differences in population structure and dynamics, juvenile mortality levels are probably also significant.