|
|
 |
|
Sea Lions
Sea
lions basking in the Queen Charlotte Islands
|
There
are two species of sea lions that occur in British Columbia
waters. The two may be found together, but they are here
for different reasons.
Sea lions, unlike the ubiquitous Harbour Seal of the coast,
are able to move about on land using their four flippers.
They are further distinguished by their longer necks and
external ears. Sea lions gather at "haul-outs",
where the two species loaf side-by-side.
They are sometimes seen on the rocks beside the ferry
route through Active Pass, and at Race Rocks near Victoria,
among many other suitable rocky islets. From December
through April, sea lions converge on the east side of
Vancouver Island to feed on herring that are returning
to spawn. The log booms at the pulp mill at Harmac has
been a good spot to see both species, and further north,
off French Creek, the herring spawn can produce a wildlife
spectacle of epic proportions.
Both species of sea lions may be preyed on by the transient
race of Killer Whales, which almost exclusively eat marine
mammals.
Steller's Sea Lion (Eumetopias jubatus)
Steller's
Sea Lions
|
These
are two distinct Steller's sea lion populations. B.C.'s
population of Steller's sea lions, which breed in three
rookeries in northern British Columbia, has more than
doubled since the early 1970s, to between 13,400 and 18,800
animals, including 2,300 pups (February 2002 survey conducted
by the Pacific Biological Station in Nanaimo). Steller's
that breed in nearby southeast Alaska have also increased
from about 11,000 to 20,000 animals over the same period.
They survive mainly on herring and other oily fish.
Steller's sea lions in the Gulf of Alaska, west of Prince
William Sound, were declared endangered in 1997. In that
part of the North Pacific, 700 kilometres northwest of
B.C., a general shift in biological makeup of the sea
has reduced the amount of oily fish, and increased the
amount of pollock in their diet, which is far less nutritious
than fish like salmon or herring.
There are large colonies of Steller's, or Northern, Sea
Lions off northern Vancouver Island, and off the southern
end of the Queen Charlotte Islands. The male, or bull,
is a huge animal, with an average weight of about 700
kilograms. Some may reach 1000 kilograms, with a body
length of up to three metres. The females are about a
third as large. Both are a warm brown in colour, with
the bulls developing quite thick manes around their enormous
necks.
The bulls compete with each other to maintain a harem
of females, defending a territory for up to sixty days.
Gestation of the single pup is almost a year, and pups
may nurse for over a year. Females are known to live up
to thirty years.
California Sea Lion (Zalophus californianus)
California
Sea Lion
|
California
Sea Lions breed to the south of British Columbia, and
after the breeding season, the bulls disperse. Many move
as far north as British Columbia, and Alaska, and this
is the most abundant sea lion in our waters through most
of the year. These bulls can be distinguished from the
Steller's by their darker pelage (which looks black when
wet) and by the prominently ridged forehead. Bulls may
weigh up to 350 kilograms, and the cows (which are not
seen in B.C.) are much smaller.
This is a playful species, which is well known as the
trained "seal" in many circuses. The population
is increasing, following decades of harvesting for meat
and oil, and as threats to the commercial fishery.
|
|
|
|