Sea Lion Island elephant seals

Sea Lion Island population of elephant seals is a small, localized one with a bit more than five hundred breeding females. After an increase in number during the 1970s and early 1980s the population was almost stable from 1989 onward; we observed an increase of about 7% in total number of breeding females and pup production in 1997, while in 1998 the population remained steady. Fecundity is very high with more than 97% of the females giving birth to a pup and mortality up to weaning is low (less than 2%): hence the population, notwithstanding its very small size, seems to be an healthy one. During the breeding season we gathered data on demography of the population by daily censuses of the whole breeding area, which comprises the sandy beaches on the eastern tip of the island.

Sketch of Sea Lion Island

Map of Sea Lion Island, with the main study area, on the right side of the arrows