Although
the caribou Rangifer tarandus is one of Canada's most widely
distributed large mammals, most Canadians know it only as
the animal on the 25-cent piece. Caribou are most familiar
to northern Canadians, for many of whom they are an essential
economic resource. The caribou's Micmac name was "xalibu,"
meaning "the one who paws," and the present name is probably
a corruption of this word.
Caribou
are found in Canada from the U.S.-Canada boundary in western
Ontario and British Columbia to northern Ellesmere Island,
more than 4000 km north. Their approximate range is shown
on the accompanying map. Some caribou are forest- and mountain-dwellers;
some migrate each year between the sparse forests and tundra
of the far north; others remain on the tundra all year.
Description
The caribou is a
medium-sized member of the deer family, Cervidae, which includes
four other species of deer native to Canada: moose, elk, white-tailed
deer, and mule deer. All are ungulates cloven- hoofed cud-chewers.
However, only in caribou do both males and most females carry
antlers. Caribou are similar to and belong tothe same species
as the wild and domesticated reindeer of Eurasia.
The
caribou is well adapted to its environment. It has a short,
stocky body and a long dense winter coat which provides effective
insulation, even during periods of low temperature and high
wind. The muzzle and tail are short and well haired. Large,
concave hooves splay widely to support the animal in snow
or muskeg, and function as efficient scoops when the caribou
paws through snow to uncover lichens and other food plants.
The sharp edges give firm footing on ice or smooth rock. Caribou
are excellent swimmers and their hooves function well as paddles.
In summer, the hooves are worn away by travel over hard ground
and rocks.
A caribou bull (male) in full autumn pelage is an imposing
animal with its rich brown or grey and white pelage, dewlap
fringe of white hair flowing from throat to chest, and great
rack of amber-coloured antlers. Adult bulls generally shed
their antlers in November or December, after they have mated.
Cows and young animals carry their antlers much longer, often
through the winter. The growing antlers have a fuzzy covering,
called velvet, which contains blood vessels carrying nutrients
for growth.
The
ability of caribou to use lichens as a primary food distinguishes
them from all other large mammals and has enabled them to
survive on harsh northern rangeland. Caribou have an excellent
sense of smell, which they use to locate lichens under the
snow.
Caribou
are very curious and hunters have found that by slowly waving
their arms, or bobbing up and down from the waist, they can
often attract caribou to close range.
Races
There are three types
of caribou in Canada: woodland, barren-ground, and Peary.
A fourth type, the Queen Charlotte Island race, is extinct.
The Queen Charlotte Island caribou Rangifer tarandus dawsoni
was a small, greyish caribou found only on Graham Island.
Little is known of this animal or of the causes for its extinction,
but deterioration of habitat due to climate change was probably
a more important cause than hunting.
The
Peary caribou Rangifer tarandus pearyi is a small, light-coloured
caribou found only in the islands of the Canadian arctic archipelago.
Average weights are 70 kg for bulls and 55 kg for cows. The
total population was estimated at 33003600 animals in
the late 1980s and was declining. Peary caribou are listed
as threatened by the Committee on the Status of Endangered
Wildlife in Canada (COSEWIC) because of their low overall
numbers.
The
woodland caribou Rangifer tarandus caribou is a large, dark
caribou that is usually found in small herds in (boreal) forests
from British Columbia to Newfoundland. Average weights are
180 kg for bulls and 135 kg for cows. In mountainous areas
of western Canada, woodland caribou make seasonal movements
from winter range in forested valleys to summer range on high,
alpine tundra. Farther east, in the more level areas of boreal
forest, they may move only a few kilometres seasonally from
mature forest to open bogs. The George River Herd, however,
is an exception to this pattern and makes extensive seasonal
movements between forested and tundra habitats in Quebec and
Labrador. This herd is currently estimated at over 500 000
animals and is the largest herd of caribou in Canada.
Woodland
caribou became extinct in Prince Edward Island before 1873
and in New Brunswick and Nova Scotia by the 1920s. Today only
a small, relic herd on the Gaspé Peninsula remains
of the maritime woodland caribou population south and east
of the St. Lawrence River. This herd is considered threatened
by COSEWIC. Caribou have also been severely reduced on the
southern edge of their distribution across the rest of Canada
and exist only in small, scattered herds from British Columbia
to Quebec. The western population of woodland caribou is categorized
as vulnerable by COSEWIC. Overhunting in some areas and changes
in habitat in others brought about the decline in numbers.
Clearing of land for agriculture has destroyed caribou habitat.
Vast areas of forest have been logged or burned and replaced
by new growth that is much more suitable for moose and deer
than for caribou. The invading deer brought a neurological
disease that kills caribou, although it does not harm the
deer. Opportunity for reintroduction of woodland caribou to
parts of its former range are therefore limited.
The
barren-ground caribou is somewhat smaller and lighter coloured
than the woodland caribou and spends much or all of the year
on the tundra from Alaska to Baffin Island. The Alaskan form,
Grant's caribou Rangifer tarandus granti, lives west of the
Mackenzie River and the Canadian form Rangifer tarandus groenlandicus
lives to the east. Average weights for the smaller Canadian
form are 145 kg for bulls and 90 kg for cows. Most (about
1.2 million) of the barren-ground caribou in Canada live in
five large herds, which migrate seasonally from the tundra
to the sparsely treed northern coniferous forests, known as
taiga. In order, from Alaska to Hudson Bay, these are the
Porcupine Herd, Bluenose Herd, Bathurst Herd, Beverly Herd,
and Kaminuriak Herd. Other barren-ground caribou (about 120
000) live in smaller herds that spend the entire year on the
tundra. Barren-ground caribou make up the majority of caribou
in Canada and are the mainstay of many northern Amerindian
and Inuit communities.
Annual
cycle of barren-ground caribou
The life of a migratory
barren-ground caribou has a fixed annual pattern. Most spend
winter in the taiga, but some always winter on the tundra.
Usually the bulls venture farthest south into the forest where
snow tends to be deepest, and the cows and juveniles remain
nearer the tree line. The herds gather in spring for the migration
to the calving grounds and to their summer range on the tundra.
Barren-ground
caribou are good navigators, unerringly walking hundreds of
kilometres in spring to their relatively small calving areas.
They tend to follow frozen lakes and rivers, open snow-free
uplands, and eskers long narrow hills of soil and rock dumped
by glaciers to their destination. Caribou are able to keep
a steady direction across frozen lakes so large that the opposite
shore cannot be seen.
The
pregnant cows lead the spring migration, followed by the juveniles
and the bulls, which tend to lag farther and farther behind.
Barren-ground caribou cows head toward traditional calving
grounds to which they return year after year, even from different
wintering areas. About 90 % of adult cows (3 years old or
older) produce calves annually. Most of the calves are born
in a 10-day period in late May or early June.
The
calves are well developed at birth and are able to travel
within a few hours. They start to graze during their first
weeks, although at that stage they can digest only milk. The
cows and calves soon move to areas where fresh-growing feed
is becoming abundant. During summer they are often harassed
by hordes of mosquitoes, warble flies, caribou nostril flies
and, in some areas, black flies. Sometimes the agitated animals
will run for many kilometres, stopping to rest only when exhausted
or when high winds temporarily disperse the insects. Running
from insects places great energy demands on the caribou, and
may retard their rate of growth by temporarily reducing their
foraging.
In
July the herds start to move en masse and feed on flowers,
grasses, and leaves of shrubs. The mating season, the rut,
occurs in late October and early November. By late September
the herds, fat and in good condition are arriving in pre-rutting
areas. Bulls spar a great deal and sometimes fight for possession
of cows.
The
migration routes have always been so well established that,
in past years, Native hunters lay in wait for caribou at places
where they would cross lakes or rivers. Occasionally, however,
the caribou did change their migration routes, and hunters
and their families located near the traditional migration
path faced starvation.
Enemies
The wolf is a natural
predator of the caribou. Wolf packs follow the migrating herds
from summer to winter range and back. Caribou are relatively
free from this predator only during calving time, when the
breeding wolves are raising their young in areas distant from
the calving ground. A wolf requires food equivalent to 11-14
caribou a year, and it may kill that many. Most wolves also
hunt mice, lemmings, other small mammals, and birds. Wolves
cannot run as fast for as long as healthy caribou, especially
in deep snow, so wolves often chase a caribou in relays, or
wait in ambush for an unwary victim.
Wolves
have a culling effect on the caribou population, as they kill
the aged, injured, or young weak animals when they are available.
Most biologists agree that the relationship between wolf and
caribou benefits both. Certainly the relationship has evolved
and lasted over tens of thousands of years.
The
human being, however, is the greatest of all caribou predators.
Many Canadian Amerindians and Inuit based their culture on
the caribou, and could not have survived in the north without
them. Some tribes were nomadic, and followed the herds year
round; others lived on caribou for part of the year. Caribou
provided food, clothing, and shelter: bones were made into
needles and utensils, antlers into tools, and the sinew into
thread; the fat provided fuel and light; the skin was made
into light, warm clothing and tent material; and the flesh
fed people and dogs.
Conservation
The take by hunters
using primitive weapons was in balance with the numbers of
caribou. The introduction of the rifle by trappers and traders,
however, made it possible to kill large numbers. It is thought
that in the three decades before 1950, kill by humans ranged
from 100 000 to 200 000 a year. In some years, this was more
than the animals' natural increase.
Originally
there were probably at least three million barren-ground caribou.
Their numbers began to decline shortly after Europeans arrived
in the North armed with rifles and seeking furs. By 1949,
when aerial survey methods made it possible to count caribou
for the first time, there were only about 750 000 animals.
Despite federal, territorial, and provincial government attempts
to reduce overhunting by supervising hunts and enforcing game
regulations, and in spite of an emergency wolf-control program,
the population continued to fall, to about 350 000 by 1955.
For a time there was fear that the caribou might, like the
plains bison, approach extinction. However, a 1967 range-wide
survey by Canadian Wildlife Service biologists showed that
the decline had stopped. Barren-ground caribou now number
about 1.3 million.
Exploration
and settlement of the north were possible because caribou
provided food. Today, caribou are still an economical source
of meat because transporting food into the north is expensive.
The vast herds of migrating caribou present a wildlife spectacle
unequalled on this continent and, as an attraction to naturalists,
photographers, and sport hunters, could contribute to a tourist
industry in the north. Wisely used, caribou can be a continuing
economic resource in the North.
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