males of E. jubatus average about 300-325 cm in length
and 1,000-1,120 kg in weight; females average about 240 - 270
kg. in length with some individuals reaching 350 kg. This single
species exhibits pronounced sexual dimorphism, slightly variable
in color, ranging from light buff to reddish brown with the
chest and abdomen a little darker. Adult males develop a massive
neck and heavy, coarse mane. Females have 2-6 retractable mammae.
E. jubatus is non-migratory, but disperses widely throughout
its range during the nonbreeding season. Rookeries are generally
located on outlying rocky islands and coastlines, providing
access to the open sea and abundant food resources. E. jubatus
feeds primarily on fish of no particular commercial value, octopus,
squid, bivalve mollusks, and crustaceans. Young fur seals, sea
otters and ringed seals are also sometimes taken. E. jubatus
can dive to depths of 200 meters, hunting mainly at night. Group
feeding sometimes occurs to control the movement of schooling
fish and squid.
The breeding season ends in late August and then the males move
throughout the range, Californian males moving north along the
coast and northern individuals moving south. Young are born
from mid-May to mid-July with births peaking in mid-June. Females
have one offspring weighing between 18-22 kg. and are dark brown
to black. They can swim at birth, staying with the mother for
5-13 days and the mother then leaves the pup to forage for food.
She then returns to the pup to suckle her young, after which
she repeats the pattern of foraging trips and returning to her
pup to nurse. At 10-14 days of age the pups form groups, playing
and sleeping together while the mothers forage. Sexual maturity
is attained at 3-8 years of age, but males rarely win breeding
territory before age 10.
of E. jubatus have dropped sharply in recent years and
the USDI has issued an emergency classification of threatened
for this species.
can be found in the Northern Pacific coastal regions of Canada,
China (vagrant populations to Jiangsu), Japan (from Hokkaido
N), Russia, USA (Alaska, Washington, Oregon, California).