Prey consumption of Steller sea lions off Alaska: how much prey do they require?
Abstract–The effects of seasonal and regional differences in diet composition on the food requirements of Steller sea lions (Eumetopias jubatus) were estimated by using a bioenergetic model. The model considered differences in the energy density of the prey, and differences in digestive efficiency and the heat increment of feeding of different diets. The model predicted that Steller sea lions in southeast Alaska required 45-60% more food per day in early spring (March) than after the breeding season in late summer (August) because of seasonal changes in the energy density of the diets (along with seasonal changes in energy requirements). The southeast Alaska population, at 23,000 ([ or -] 1660 SD) animals (all ages), consumed an estimated 140,000 ([ or -] 27,800) t of prey in 1998. In contrast, we estimated that the 51,000 ([ or -] 3680) animals making up the western Alaska population in the Gulf of Alaska and Aleutian Islands consumed just over twice this amount (303,000 [[ or -] 57,
