Effect of the inter-annual variation of wind speed on the weaning mass of the Cape fur seal Arctocephalus pusillus at Lüderitz, Namibia

Abstract

Abstract by author:

This study examined the effect of the inter-annual variation of wind speed on the weaning mass of the Cape fur seal pup Arctocephalus pusillus at a colonies near Luderitz (Atlas and Wolf bay). Large numbers of Cape fur seal pup Arctocephalus pusillus were weighed at regular intervals throughout their lactation period between 1987 and 2001 at Atlas Bay. Growth rate and weaning weights were estimated from regressions of weight change with time. Female pups had significantly lower growth rates and weaning weights than males. Seasonal differences in growth rates were substantial and there was also indication of variation in pup growth within seasons. Variation in growth rates between years, suggest that there are differences in the prey abundance availability to lactating females. The seasonal Coastal Upwelling Indices has showed a remarkably high correlation with pup growth. Pups born earlier in the season were heavier and in better condition