BODY-WEIGHT AND GROWTH OF JUVENILE MALE NORTHERN FUR SEALS, CALLORHINUS-URSINUS

To mark-recapture study conducted in 1987-1992 provided weight measurements of juvenile male northern fur seals (Callorhinus ursinus) on St. Paul Island, Alaska, at ages ranging from approximately 1. 5 mo to 5 yr. Males born in 1987 tended to weigh less at ages 3 and 4 yr than those born in other years. Weights of individuals at ages 2, 3, and 4 yr were significantly correlated with their weights as pups (P < 0.05). Weights at ages 2 and 3, 3 and 4, and 4 and 5 yr were significantly correlated (P < 0.001), although weight changes with age were highly variable. Data indicate that larger than average male pups born during 1987-1990 were more likely to survive, but this effect was less evident than among pups born during 1960-1965 when average pup weights were lower.