|
Hoary marmot
Hoary marmots are often described as having an "icy-grey"
appearance. The front half of the back is white with black hair. The
rest of the back is brown. Hoary marmots have cinnamon or brown
heads and necks, with white edges around their noses and lips. The
rest of their bodies are covered with brown hair. Males are usually
slightly larger than females. Hoary marmots range in size from 45 -
57 cm in length, with a tail that extends 17 - 25 cm beyond the
body.
Hoary marmots, and all members of the genus Marmota, have thick,
slightly curved claws. These claws are heavier on the front feet
than they are on the hind feet. The palms are hairless and have five
pads; their soles are also naked, but have six pads.
Their eyes are small and circular and they have short, rounded,
hairy ears.
Reproduction
The breeding season begins shortly after hoary marmots emerge from
hibernation in mid May. Successful copulation is followed by a
gestation period of 25 - 35 days, after which a litter of 2 - 5
offspring are born. The young stay in their mother's burrow until
they are approximately one month old. At this time they are
fully-furred. Because they spend their first month underground, it
is difficult to know how well developed the young are at birth. Once
the young have emerged from the burrow, they will be weaned in about
two more weeks. Hoary marmots reach sexual maturity at two years of
age. Hoary marmots usually disperse when they are two years old.
While dispersing, the mortality rate of the two year olds is very
high. This may be a result of the fact that dispersing hoary marmots
do not have protective burrows in which to dive into to escape
predators.
Hoary marmots are monestrous, that is they only have one estrous
cycle per year, and thus they never produce more than one litter per
year. Although they are able to breed every year, hoary marmots
usually only breed every other year.
Behavior
Hoary marmot social systems are not as rigidly defined as is the
case in other marmot species. There, is however a loose dominance
hierarchy in which adult males are followed by adult females,
two-year-olds, yearling, and finally young of the year. These
dominance relationships are loose in that any given interaction
between animals might not follow the pattern, and only among adult
males can the results of interactions be reliably predicted. In
areas where food is plentiful, marmots live in colonies consisting
of one dominant adult male, a few females and their offspring, and
perhaps one or more subordinate adult males. The dominant hoary
marmots are called colony males and they are the only males who mate
with the females in the colony. The subordinate adult males, called
satellite males, are usually smaller and younger than the colony
male. Colony males engage in a behavior called gallivanting during
which they wander through their colony in search of excitement,
usually of a sexual nature. Colony males are sometimes challenged by
satellite males and physical fights can occur. Colony males almost
always drive off satellite challengers. These fights, however, are
never fatal.
Little is known about the actual mating behavior of hoary marmots
because most matings occur inside burrows.
In areas where food is more scarce, hoary marmots do not exist in
colonies. Food shortages require hoary marmots to increase their
ranges, which can become large enough that a male will not be able
to guard more than one female and feed himself at the same time. In
these cases, hoary marmots are monogamous, and little male/male
competition.
Hoary marmots do hibernate in the winter, and the time at which they
enter hibernation depends on where they live. Animals in the
southern parts of their range (Washington, Idaho, Montana) hibernate
later than animals who live in northern Canada and Alaska. Hoary
marmots have been known to begin hibernating as early as the middle
of September. They usually emerge from their burrows around the
middle of May
All marmots, including hoary marmots, have many vocalizations. A
common call is the alarm call which is given anytime anything comes
near a burrow. The approaching animal need not be a predator as
hoary marmots will give their alarm call when non-predators get too
close. The alarm call is a high-pitched shrill whistle. The calls of
hoary marmots are usually higher in frequency and longer than the
calls of other marmot species.
Food Habits
Little is known about the food habits of hoary marmots. They are
mainly herbivorous, and in the spring and early summer, hoary
marmots eat leaves and blossoms of many different herbaceous plants
and grasses. Late in the summer, hoary marmots like to eat plenty of
seeds. There have been a few cases of hoary marmots being
carnivorous or even cannibalistic. Cannibalism most likely resulted
from scavenging, as there have been no observed fatal fights between
hoary marmots. Hoary marmots appear to drink almost daily and they
have frequently been observed eating snow. In places where standing
water is scarce, hoary marmots seem to get all the water they need
from the plants they eat or from the morning dew.
Back to
Pet Rats, Mice, Gerbils, Jirds, Voles,
Lemmings and other Rodents
Other rodent pages you might be interested in:
Orphaned babies
Tricks you can
teach your pet
|
