Galimberti,F. & Boitani,L.  1999. Demography and breeding biology of a
small, localized population of southern elephant seals (Mirounga
leonina). Mar. Mammal Sci. 15(1): 159-178.

Abstract
Southern elephant seals have been studied in depth in most of their
breeding range. One notable exception is the Falklands Islands
population. We present data on demography and breeding biology of
elephant seals of Sea Lion Island, the main breeding site of this
species in the Falklands. Sea Lion Island shelters a small, localized
population of southern elephant seals (516 breeding females in 1995 and
518 in 1996). Comparison with the few available census data collected
prior to our study suggests that the population has been stable in the
short term (1989-1996). Females produced pups at maximum rate and pup
mortality was low (2.13%). Breeding sex ratio was strongly unbalanced,
with about 14 females per breeding male and 47 females per harem-holding
males at peak haul-out. Survival rate between breeding seasons was very
similar to that recorded in other populations and was in accordance with
clinical variation with latitude. Sex ratio at birth was balanced, and
no significant weight dimorphisms at weaning between sexes was detected
(males: 135.4 kg; females: 132.0 kg). Weaning weight was correlated with
size class of the mother.