A YEAR IN THE LIFE OF A MOOSE
As the snow cover begins to melt and flow downslope to the frozen
stream beds, pregnant cow moose look for safe and secluded places
to give birth. Calves are born from mid-May to mid-June. Some
cows birth at tree line in the subalpine zone, while others birth
level in the valley bottoms. In the southwest Yukon, grizzlies
that spend much of their time in the subalpine in spring, kill
percent of each year's calf crop. Most of these kills are made
before the calves reach eight weeks of age. Wolves take fewer
than grizzlies, but continue to prey on the older calves year-round.
Many cow moose breed for the first time at 1 1/2 years
of age and every year or two
afterwards. Where food is plentiful, twins are common and triplets are occasionally
From late spring through the summer, moose feed
on the new buds and fresh growths of willow. Aquatic plants, such
as the yellow
pond lily, draw the
moose out into ponds and lakes at this time of year.
Antler development begins in March or April, first
in older bulls and last in yearlings. During the growth period,
the soft spongy antlers are covered
a dark brown, velvety skin.
Waterways are important feeding areas for moose, but they also
provide escape routes from the ever-present danger of predator
attack. When pursued
or bears in the summer season, moose often head for water where their
long legs give them an advantage.
The moose is a browser; "eater of twigs" as
the Algonkian Indian name translates. In a single day, an adult
can consume about 20 kilograms
leaves, shrubs and other land and water plants. A ruminant like the
domestic cow, the moose has a series of stomachs to help digest
its woody diet.
It can sometimes be seen chewing its cud.
Those calves that survive through the heavy spring
predation, grow dramatically over their first summer. Adding as
much as two kilograms
per day, they
weigh about 180 kilograms (400 pounds) by the time autumn arrives.
Cow moose can experience three estrous or breeding periods in
the fall. The second estrous, which occurs between the last
September and the first
October, is the period of greatest fertility.
Rutting, which commonly occurs at treeline in the
subalpine zone, brings new sounds to the landscape. The coughs,
grunts, and bellows
moose are heard
along with the rubbing of antlers against trees and the calls
of the cows. Finally the clash of antler to antler resounds
begin their shoving
Dominant bulls try to keep lesser bulls away from
their group of cows, which can number up to ten or more. At the
their cows, ready to mate with any that come into estrous.
All in all it's an incredibly demanding time for these bulls.
for a month
during the rut; their necks swell and they become unusually
aggressive. But it's a short-lived power they wield. When
the rut is over
in October, a dominant
is often exhausted, undernourished, and has lost up to 20
percent of his weight. Sometimes the price for perpetuating his
is a weakened
the bull more vulnerable to potential causes of mortality.
Prime bulls drop their antlers from late November
through February. Young bulls lag a month or more behind.
Winter is a season of reduced food supplies for moose,
and increased predation by wolves.
Fresh willow buds, leaves and aquatic plants are no longer
available. Forage is restricted to the woody twigs of
poplar, birch, alder
and willow. In
late winter, when food supplies are at their lowest,
some moose move into aspen
stands and use their front teeth to scrape the bark down
to the nutritious layer of
cambium underneath. In areas of heavy snowfall, many
moose will move down to the lower valleys as winter progresses.
An average wolf pack (seven to nine wolves)
will kill one moose every five or six days through the winter.
and older age moose, any moose can be vulnerable to
wolf predation, depending on the terrain, snow conditions,
and its response
to attack. Generally,
a moose that remains stationary can successfully defend
itself from wolves, while a moose
that flees is attacked from the rear and often brought
down. By backing into
a thicket of trees, a moose can fend off wolves with
its powerful front hooves.