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Anchorage Alaska
99J*TS ABOUT CANADIAN MUSK-oXEN ,
'
J .s o Tener ....Department of Northern Affairs and National Resources
Canadian Wildlife Service
Canada has a rare and valuable asset in the herds of musk-oxen
(Ovibos moschatus ssp.) frequenting her barren-lands and Arctic islands.
She shares with Greenland
a wild population of these mammals which is of
.
.
great scientific value.
When their .- numbers have increased to the point
where utilization is feasible, musk-oxen in Canada will be of economic
value also.
The complete .extermination of many herds and the near elimination of as many others, particularly on the Canadian Arctic mainland in
the closing half of the 19th and during the first fifteen years of the
20th centuries, created real concern for the survival of this species.
To conservationists it was unthinkable that a large ungulate, well adapted
to living in a rigorous Arctic environment, . should become extinct.
Canadian
Gov~rnment
The
passed an Act in 1917 protecting musk-oxen completely,
and forbidding any killing, and in 1927 set
a~ide
the Thelon Game Sanc-
tuary in the Northwest Territories for the specific purpose of providing
an area where the local musk-oxen and other valuable wildlife could increase without human interference in any form.
The number of recent re-
ports recording observations of musk-oxen in many areas, particularly where
the animals were thought to have become extinct, suggests that the regulations and the Sanctuary are having the desired effect.
As part of the general policy of assessing the wildlife resources
of the Canadian Arctic, the Canadian Wildlife Service initiated a specific
investigation in the spring of 1951 to determine the distribution, numbers,
and biology of musk-oxen.
Two populations of musk-oxen have been studied
to date, one in 1951 on Fosheim Peninsula, Ellesmere Island, N. W. T., 700
miles from the North Pole ', and the other in 1951 and 1952 in the Thelon
- 2 -
Game Sanctuary, N. W. T., over 1,000 miles to the south.
This report is
a brief review of the findings of these studies, together with certain ·
historical information obtained from earlier researchers and writers.
DISTRIBUTION
At one time, before they were hunted for the value of their
skins . and for food by natives, whalers, and explorers, musk-oxen had a
wide, if relatively sparse, distribution throughout the barren-land regions of the !rctic mainland and Arctic islands of Canada.
One important
exception to this is that there are no known records of musk-oxen on
Baffin Island, possibly because of their extinction long ago by nat ives,
or because this island, for reasons unknown, was never colonized by muskoxen.
The total numbers in existence at the time of Samuel Hearne in
the 1770's are unknown but probably were .very few when compared with
original numbers of caribou.
Hearne has provided evidence that even in
his time musk-oxen were restricted in numbers and distribution for he has
commented on the fact that he travelled for days over the Arctic main- '
land without seeing any.
From 1862 to 1916 the Arctic mainland popula-
tion was drastically reduced.
Musk-oxen were killed for their skins for
trading purposes and for · skins and meat for whalers wintering along the
Arctic coast east of the Mackenzie River delta.
The Hudson's Bay Company
generously has made available to the Canadian Wildlife Service its records
of musk-ox furs turned in to its posts in northern Canada.
1916 a total of
5,408 were
~5,101
turn~d ;
a minimum kill .ot;:.
From 1862 to
skins were received by this Company, of which
1n from 1888 to 1891.
~sk-oxen
These figures must be regarded
during this period o_f . 58 years, for whalers
and natives would ··.have kept many skins -for
the~ r:
own use .<
as
- 3 On the lrctic islands similar heavy killing is recorded.
..
In
the name of exploration, 400 animals were killed on Melville Island early
in the present century as were several hundred on Ellesmere Island at the
same time.
before
The population on Banks Island was exterminated by natives
l,?J.
The result was that by 1930 the population of musk-oxen in
Canada was estimated by Dr. R.M. Anderson, National Museum of Canada, to
be between 9,000 and 10,000 animals, of which ?00 were on the mainland,
including 2?0 in the Thelon Game Sanctuary.
Today the picture is a happier one.
Musk-oxen are increasing
steadily, if slowly, in numbers and are being reported in areas such as
Banks Island and the area north of Great Bear Lake, where
were believed to have been exterminated.
fo~merly
they
The population in the Thelon
Game Sanctuary is believed to be over ?00 animals and shows every indication of increasing at a healthy rate.
SOCIAL STRUCTURE
..
Musk-oxen are essentially gregarious, feeding and travelling
in herds.
The size of herds varies from small units of four or five
animals to as high as one hundred.
Generally, the large herds are the
aggregations of the small units, formed after the breeding season has
finished.
Mature bulls are an exception, for they are not as gregarious
as other animals, frequently being solitary in their habits.
This is
particularly true before and after the breeding season.
Herds exist throughout the year but probably do not contain
the same individuals from year to year, because of the mingling of herds
in the autumn and the general dispersal afterwards into smaller units.
- 4 -
When grazing or browsing, the individuals of a herd may be
spread over an area of several hundred square yards, but the herd unity
is not lost, for individual cows or immature animals that have become
more widely separated from other individuals than is customary, rejoin
the herd immediately upon noticing their unusual situation.
The desire to remain in herd formation appears to be an outstanding characteristic of these animals.
The value and perhaps the
original function of this social character is evident when a herd is
attacked by wolves.
The musk-oxen group together _ in a rough circle,
facing outwards, with calves and immature animals between the adults.
One wolf or a small pack would not be likely to attack successfully such
a defensive formation.
The sharp, heavy horns of adult cows and bulls,
a heavy coat of long hair, nimble feet and
formidable opponents.
bodies make them
When sled dogs attack musk-oxen, and probably
when a large pack of wolves does so, bulls
dashes towards the predators in attempts to
the herd.
po~erful
a~d
adult cows make short
go~e
them and then back into
Under these circumstances it is possible that some musk-oxen
would be killed.
FOOD AND RANGE
Food of musk-oxen varies with the season and the terrain.
In
, summer, on the Canadian Arctic mainland, the animals are browsers and
grazers, feeding on willow, grasses, forbs and sedges.
On the Arctic
islands willow growth is confined to prostrate plants sparsely scattered
over large regions and musk-oxen must use a larger proportion of grasses
and plants such as saxifrage (e. g. Saxifraga oppositifolia L.) and dryas
(Dryas integrifolia M. Vahl.).
·.
- 5 On Fosheim Peninsula, Ellesmere Island, where range studies
•
were carried out, it was found that 85o5 per cent of the surface of
the spring and summer range under study was rock, gravel, silt, and clay.
The total vegetative cover was 14.5 per cent, of which grasses composed
4.8 per cent and willow 2o5 per cent, of the 10,000 points sampled by
the Clarke Point Sample Method.
Winter food is obtained in hilly country where
vegeta ~i on
kept partly or completely free of snow by prevailing winds.
is
Dried
grasses of Poa, Alopecurus, Agropyron, Arctogrostis and Festuca genera
and dried forbs are the main food species at this time of year.
The extent of .the seasonal movements between ·winter and
summer ranges depends upon the nature of the country in which the
animals liveo
In the Arctic islands preliminary evidence suggests that
these movements do not , involve distances of more than 50 miles.
On the .
mainland of Canada evidence suggests that musk-oxen there may move a
distance of 50 to 100 miles or more to reach suitable feeding areas.
BREEDING BIOLOGY
Much remains to be discovered about the reproductive biology
of these ungulates.
Their remote environment and relative scarcity
make it a difficult and expensive undertaking to try to conduct the
continuous long-term investigation necessary to gather the facts.
Some information is available, however. It is believed that
musk-ox cows are sexually mature at four, possibly at three years of
age, and bulls at five or six years of age.
Cows do not seek a soli-
tary spot to give birth to young, but remain with the herds of which
they are members.
Evidence obtained during the present study
sugge~s
that calving occurs in alternate years with one calf delivered at a time.
Twins are born rarely. Reasons for the low reprcxilctive rate are as yet unknown~
- 6 but an important factor may be a lactation anoestrum in cows that have
suckling calves.
•
This would prevent conception during the year a calf
was born, with the result that there would be no birth the followi ng
year.
This argument has some merit at present, for in all cases where
a yearling has been observed in association with a cow, that cow has been
without a calf.
Other factors, of course, may prevent calving each
year~
but as yet their nature remains to be determined.
the
Breeding occurs in late July and August and/calving seas on
extends from about the middle of April to the end of May.
These dates
appear to be true for the entire range of musk-oxen, which is spre ad over
a distance of 1,100 miles, from latitude 64° · N. to 82° N.
It is interesting to speculate what the nature of the mechanism
controlling this apparent uniformity of breeding dates may be.
The re is
a growing body of literature concerned with the influence of light, or
alternating periods of light and darkness, on the onset of breeding in
mammals.
It is possible that light influence is a major
oxen breeding and calving times.
The northern and
fact~r
southe~n
in
mu sk~·
limits qf
musk-ox distributional range have markedly different light conditi ons.
At latitude 80° N. on Ellesmere Island, the habitat of at least 500 muskoxen, there is darkness 24 hours a day from October 22 to February 20o
Daylight increases in length until April 14, from which date unti l
August 31, it is continuous.
At latitude 64° N. in the Thelon Game
Sanctuary, however, 24-hour daylight or darkness does not occur.
On
June 21 there is a maximum of 18 hours sunlight, which decreases to four
hours December 21.
In review, then, periods of sunlight grow shorter before muskoxen commence to breed in the Thelon Game Sanctuary, but the sunli ght on
.
I
..
- 7 .; ,.
• Fosheim Peninsula is of 24 hours a day duration throughout the mating
. period.
It would .appear •that if alternating periods of light intensities
initiate the onset of oestrus in musk-oxen, this mechanism must act on
the animals before the onset of maximum daylight to have uniformity in
breeding dateso
There is a suggestion that •this causal mechanism may be
associated with the changing light periods before and during the .spring
equinox.
Fighting between adult bulls for the possession of herds and
essentially of cows, occurs chiefly_during the months of July and August.
Sporadic fighting at other times of the year does not appear to be
significant as far as herd dominance is. concerned.
In all cases qbserved
by this writer, bulls in possession of herds were well-matured animals.
Solitary bulls, on the other hand, ranged from mature young animals to
the very old.
A combination of
experienc~
and strength is probably
necessary for the successful conclusion of conflicts for cows.
As
immature animals are tolerated in · a herd until they reach sexual maturity
full fighting experience would not be gained until after the fifth or ·
sixth year of ageo
VITAL STATISTICS
The determination of the numbers of the. various age and sex
classes in herds, apart ,from calves and adults, is uncertain because of
the difficulty in correctly identifying immature animals.
Information
obtained to date on adults indicates there are more cows than bulls,
the proportion on Fosheim Peninsula, Ellesmere Island, being two cows
for each bull, a~~ ~n the Thelon Game Sanctuary, 1.2 cows for each bull.
These proportions , may not . represent a true picture because the solitary
habits of many .bulls makes it , doubtful whether all were counted.
The
•
- 8 deferred maturity of bulls may distort the adult sex proportion and so
,may increase
mortality of bulls because of predation when the y are
•
..
solitary in their habits.
The calf percentage in a musk-ox population is low when compared with many other ungulates.
On Fosheim Peninsula, for
exam ple~
calves in 1951 composed 9.3 per cent of 215 animals, and in the Thelon
Game Sanctuary in 1952 they were 11.2 per cent of 169 musk-oxeno
Calf
survival was found to be extremely low in 1951 on Ellesmere Island 7 only
three yearlings being present in the population studied.
In the Thelon
Game Sanctuary, however, survival was found to be slightly over 60 per
cent, for a survey in 1951 revealed a calf percentage of 11.8 in the
total population, and in 1952 the yearling percentage was 7.1 in the
same population, a drop from the calf numbers of 39.8 per cent.
MORTALITY FACTORS
The knowledge and importance of mortality factors in musk-ox
populations are as yet unknown.
wolf may be a mortality agent.
There is evidence to suggest that the
Numerous instances in the literature
record the killing of musk-oxen, chiefly solitary animals and often
bulls, by wolves.
Musk-ox remains have been found in wolf scats and
wolf stomachs, but this only suggests that wolves will eat musk-oxe n,
not that they have killed them.
A musk-ox herd presents a formidable
defense to wolf attacks, but it is believed that calves and yearlings
could be taken by a large pack of wolves, even though protected by the
.
A
herd.
The fewness of yearlings found in herds on Fosheim Peninsula
suggests an appreciable mortality of this group.
Adverse weather during
the period of birth in April and May, harsh environmental condi tions
- 9 • during the first winter of a calf's life, and perhaps wolf predation,
are possible important mortality factors.
In conclusion, Canada's musk-oxen, in the rather distant
future, should become an increasingly valuable big game resource.
From
a scientific viewpoint they present extraordinarily interesting problems
of research and management.
From an economic viewpoint they may again
reach the level of abundance where utilization may be permitted by
natives or resident white people.
It is hoped that by eventual restock-
ing of depleted areas and careful management of existing stocks, muskoxen once more will be game animals of more than scientific interest.
Presented to the 19th North
American Wildlife Conference,
Chicago, Ill., March 8, 9, and 10, 1954.