This Species is Protected Under the

MARINE
MAMMAL

PROTECTION ACT OF 1972

WALRUS

(Odobenus rosmarus)

jhe walrus is a member of the
l pinniped family, which also

includes sea lions and seals.
Walrus differ from some seals in that
they can turn their hind limbs forward.
This characteristic enables them to
raise themselves up, giving them greater
freedom of movement on land. Two
subspecies, the Atlantic and Pacific wal-
tus, live in the arctic and subarctic
regions of the Northern Hemisphere.
The Pacific walrus is the largest.

The walrus is covered by a thick
layer of fat and a tough leathery skin
with a thin layer of hair which is light
brown on adults and almost black on
young walrus. The walrus’ head is small
in comparison with its heavy, clumsy
body, and the upper lip is thick and
fleshy with a stiff moustache made up of
bristles which are important sensory
organs. Although there are other teeth
in the upper jaw, it is the greatly
enlarged canine teeth, called tusks, that
give the walrus its distinctive appear-
ance. Both the male (called a bull) and
the female (called a cow) have tusks;
however, those of the male are much.
larger. Males may weigh over a ton and
reach a length of more than 10 feet.
Females are about a third
smaller with a maximum
length of about 9 feet.

In the summer, bulls
live together in bachelor
groups, but during the
midwinter mating season
(January through March)
walrus congregate in
groups called mobile leks
in regions of ice-free
water. Bulls may fight
viciously over cows, and
the victorious bull always

Both the male (bull) and the
female (cow) have tusks;
however, those of the male
are much larger.

keeps an eye out for other males who
would steal his females if given the
opportunity.

Females give birth to a calf every 2 to
3 years. The young are born out on the
ice in April or May. At times when a
calf is not sleeping or nursing, the
mother allows it to crawl over her or
she may play with it, holding it between
her front flippers and lifting it into the
air. A calf may nurse for up to 2 years.

The adults may take a swim to feed,
but the young are never left completely
alone. While both sexes watch for ene-
mies such as polar bears, the females are
solely responsible for the protection of
their offspring. If a walrus group, or lek,
is disturbed and leaves the ice floe, the
adults stay close to their young to pro-
tect them.

Walrus primarily eat species that
dwell on the sea bottom, such as mol-
lusks; salt worms; crabs, shrimp, and
other crustaceans; and octopus. The
walrus drags its tusks like sled runners
along the sea bottom, rooting out
buried prey with its snout and stiff facial
bristles. Occasionally walrus may con-
sume other pinnipeds such as spotted,
tinged, and bearded seals.

Tusks also serve as an indicator of
social rank and may be used as protec-
tion. Sometimes, when a walrus wants
to rest while still in the water, it will
hook its tusks over the edge of an ice
floe. Tusks may also be used to break up
an ice floe to keep breathing holes open
or to retrieve calves that have become
stuck in the ice.

Walrus spend most of their lives at
sea, although they frequently come out
of che water, or haul out, onto ice floes
or land to rest. They also leave the
water to give birth to their young and to
shed their hair. Keeping mainly to the
moving ice packs, walrus migrate north
in spring and south in winter.

For thousands of years, the walrus
was regarded by Eskimos and other
Native people of the North as having
supernatural powers and human attrib-
utes. It was also a natural resource of
major importance to their culture. They
obtained food and fuel from the walrus,
as well as raw materials for making
tools, shelter, boats, sleds, and clothing.



‘ne wallus was nunted for centuries Dy
Russians, Americans, and others for its
valuable ivory tusks and oil.

In the United States, the walrus
became a federally protected species
with the passage of the 1972 Marine
Mammal Protection Act. This Act
established a moratorium on the taking
and importation of various marine
mammals, their parts, and products.
However, the Act allows Eskimos and
other Alaskan Natives to take walrus
for subsistence, and their parts for use
in certain handicraft articles.

The monitoring of the walrus popu-
lation through periodic surveys is one .
effort the U.S. Fish and Wildlife Service Females give birth every 2 to 3 years. The young are born out on the ice in April or May. From time to time
undertakes to fulfill its responsibilities some of the adults take a swim to feed, but the young are never left completely alone,
under the Act. The last survey was
done in 1990 in cooperation with
Soviet biologists, and at this time, the
walrus population appears stable, with
more than 200,000 individuals.

Among the threats facing the walrus
today are habitat alteration, illegal
hunting, human activities on or near
hauling-out grounds, and disturbance
by commercial fishing and
oil and gas exploration
and extraction.

The walrus is covered by a thick layer of fat and a
tough leathery skin. The hair on adults is light brown
and almost black on young animals. The walrus’

head is small in relation to its heavy, clumsy body, BIOLOGUE SERIES
and the upper lip is thick and fleshy with a stiff Prepared by:
Moustache made up of bristles. U.S. Department of the Interior

U.S. Fish and Wildlife Service
1995