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California Sea Lion
Zalophus californianus
California Sea Lion Behaviour
California Sea Lion Breeding Behaviour
California sea lions breed on the Channel Islands off southern
California and on islands along the Baja California west coast
and half way into the Sea of Cortez (Reeves et al. 2002). The
largest numbers breed on San Miguel Island (Wilson and Ruff
1999). Thousands of sea lions haul out on the sandy beaches.
California sea lions are polygynous breeders where adult males
establish territories and where females gather to choose
mates. Males defend these territories for 4 to 6 weeks using
displays backed up occasional fights. A male might hold a
territory for six years (Wilson and Ruff 19999). Pups are born
on land in late May, June and early July. After about a week,
the pups go to sea with their mothers to catch fish and
periodically coming ashore to nurse. While mothers are at sea,
pups will gather in large herds. Pups are weaned after about a
year but some continue to nurse up to two years (Wilson and
Ruff 1999). Females enter estrous a few weeks after giving
birth and prepare to mate.
California Sea Lion Feeding Behaviour
California sea lions eat fish and squid by diving to depths of
as much as 500 m but mostly near the surface. Most feeding
takes place near shore, seamounts and continental shelf
regions where ocean water upwells from the depths. These
nutrient laden waters have large schools of fish such as
anchovy, mackereal and rockfish. Sea lions can remain under
water for up to 12 minutes (Reeves et al. 2002). Sea lions
also station themselves at mouths of rivers to intercept fish
entering the rivers to spawn.
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