Spanish Joe tells us
About Groundhogs
Groundhogs or Woodchucks
This animal, sometimes completely black
or completely white, is one of Canada’s largest true hibernators and the
subject of a great deal of medical research. It spends much of its time
eating and sunning when not hibernating or caring for young and is the
major hole-digging mammal over much of eastern North America, and in
some places in the west, providing all sorts of animals with shelter
Description
The groundhog Marmota monax—often called
woodchuck—is a rodent and belongs to the large group of mammals Rodentia,
which includes squirrels, prairie dogs, and chipmunks. Within this large
group the groundhog is considered one of the marmots.
Among North American rodents, only beavers and porcupines are larger
than the marmots. Groundhogs are stocky little animals with a flattened
head. They commonly weigh 2 to 4 kg, and large ones may be heavier in
the autumn. They measure 40 to 65 cm total length, including a short
bushy tail about 15 cm long. Fur colour varies from place to place and
between individual animals. It ranges from yellowish to dark reddish
brown, with an intermediate brown colour being the most common shade.
The fur is usually grizzled in appearance because of light-coloured tips
on the hairs. The belly fur is commonly straw-coloured and the feet
black.
Groundhogs are occasionally found with melanistic or albino fur. The fur
of melanistic specimens is completely black. Albinos, on the other hand,
have no colour in their fur at all, and even their eyes lack
pigmentation, merely showing a pinkish tinge from blood vessels near the
surface. Being white, they are conspicuous, and usually fall easily to
predators.
Because groundhogs are burrowing mammals, their feet have sturdy claws
and their legs are thick and strong. Their forefeet, the principal ones
used for digging, each have four well developed claws, and the hind feet
have five. They escape from enemies by diving into burrows, which may
account for the fact that their top running speed does not exceed 15 km
per hour.
A close relative of the groundhog’s, the hoary marmot or whistler, lives
in the mountains of western North America, from Washington, Idaho, and
Montana northward into Yukon and Alaska. It inhabits tundra, alpine
meadows, and rock slides in mountains. Two other marmots, very closely
related to the hoary marmot, but differing from it in colour, live only
on high portions of Vancouver Island and the Olympic Peninsula. The
rockchuck, or yellow-bellied marmot, found from California, Texas, and
New Mexico to British Columbia and southwestern Alberta, is another
close groundhog relative. Where the groundhog is brownish, this somewhat
smaller cousin tends to be yellowish. It favours rockier country and
higher elevations (over 3 000 m) than the groundhog, but it is also
found on agricultural land in foothills and valleys.
Scientists recognize as many as nine varieties or subspecies of
groundhog, mainly based on subtle differences in colour or skull
characteristics.
Signs and sounds
.GIF)
Groundhogs
seem constantly on the alert when outside their burrows and give a
shrill warning whistle when alarmed. When fighting, seriously injured,
or caught by an enemy, groundhogs give a squeal. They also produce a
sound by grinding their teeth. In addition, groundhogs can give a low
bark, but the function of this particular sound is unknown.
Habitat and habits
Groundhogs prefer open areas such as
fields, clearings, open forests, and rocky slopes. They generally dig
their burrows in areas where luxuriant grasses and other short-growing
plants provide food. They tend to avoid damp or swampy areas.
Summer burrows are often in the middle of pastures and meadows, and the
animals will have a denning burrow, used only in the winter, in woody or
brushy areas nearby. Winter burrows, whether separate or part of a
groundhog family’s main burrow system, are usually deep enough to be
located below the frost level.
Burrows usually have a main entrance, one or more "spyholes" for added
safety from enemies, and separate toilet and nesting chambers. The same
nest is used for sleeping, hibernation, and as a nursery. It is made of
dry grass in a chamber that may be 45 cm wide and over 30 cm high.
.GIF)
When not hibernating or caring for young, groundhogs spend much of their
time eating and sunning. They love to stretch out on warm ground, a
smooth rock or along a low branch of a convenient tree. Their tree
climbing ability is limited, however, and infrequently used.
In preparation for their long winter sleep, or hibernation, groundhogs
grow enormously fat towards the end of the summer. They begin
hibernation with the onset of freezing weather, the adults before the
young ones, who probably need extra time to put on sufficient fat to see
them through the winter. The first adults to hibernate disappear late in
September, and all groundhogs are underground in October.
Hibernation is a process of deep comatose sleep. Bodily functions are
greatly retarded, allowing the accumulated body fat to nourish the
animal throughout the winter. Body temperature may drop to 3°C (just
above freezing), and the heartbeat will drop from its normal rate of
about 80 beats per minute to only four or five. The breathing rate and
consequent consumption of oxygen are also much reduced. When the animals
emerge in the spring, they generally still have a good deal of body fat
left. This is necessary because emerging in March, as many of them do,
they find little food about them. They may even burrow up through snow
to reach daylight. Several weeks may pass before the snow is all gone
and there is abundant fresh green plant growth to eat.
Because they are among Canada’s largest true hibernators, groundhogs are
the subject of a great deal of medical research. Scientists are studying
their ability to lower their body temperature, reduce their heart rate,
and reduce their oxygen consumption.
Unique characteristics
Groundhogs are the major hole-digging mammals over much of eastern North
America, and in some places in the west. All sorts of animals are able
to thrive because of the shelter supplied by groundhog holes. The list
includes a wide variety of fur and game animals, some of which destroy
huge quantities of farm pests, such as rats, mice and insects. Skunks,
raccoons, foxes, rabbits, and snakes all take shelter in groundhog
holes.
On the second of February each year, much of North America observes
Groundhog Day. On that day, according to folklore, the groundhog
awakes from its long winter sleep and comes out of its den. If it sees
its shadow it will go back in, and we will have another six weeks of
winter. If it does not see its shadow it will remain awake and active,
and we will have an early spring. This popular old legend apparently
came to North America with early settlers from Europe, where it is
believed in some parts that bears or badgers behave in the same manner.
Although most people recognize that the legend has no basis in fact, it
provides a welcome mid-winter diversion, which is usually promoted by
the news media. In reality, most groundhogs do not come out of
hibernation until March, or even later in the north.
Range
Groundhogs are widely distributed in
North America and are particularly common in the east where they are
found from Alabama and Georgia in the United States to northern Quebec
and Ontario. In the west, their range extends northward to Alaska and
through southern Yukon and Northwest Territories. Groundhog distribution
is spotty everywhere on the edges of the range.
The groundhog, like a small number of other animals (for example, the
coyote), has prospered because of deforestation and agriculture. Before
the felling of the forests of eastern North America, the groundhog
population was many times smaller than it is today. When large numbers
of European settlers began to farm what had once been dense forest,
groundhog numbers skyrocketed among the woodlots, pastures, and
cultivated fields. Although farming has been abandoned in many parts of
eastern Canada, today’s landscape of mixed bush and pasture still suits
these familiar burrowing mammals.
Feeding
Groundhogs prefer to eat fresh green
vegetation. They eat a wide variety of wild plants, clover and alfalfa,
and garden vegetables if they can get them. On rare occasions, they eat
snails, insects, or young birds that they come upon by accident. Early
in spring they eat bark and small branches.
Breeding
Young groundhogs are born in April and
May (in Canada, mainly in May) following a gestation, or pregnancy,
period of 30 days. One litter, usually with four young, is produced per
year. Groundhogs are blind and helpless at birth, about 10 cm in length
and about 30 g in weight. At about 28 days old, their eyes are open, and
they are covered with short hair. They are weaned, or have made the
transition from mother’s milk to solid foods, when they start to emerge
from the burrow at five to six weeks of age. Groundhogs grow rapidly.
They weigh 570 g at eight weeks of age and become very fat for
hibernation. Groundhogs have been known to live for 10 years, although
the average life span is probably much less.
Conservation
Groundhogs are a natural prey for large
carnivorous animals, such as bears, wolves, lynx, bobcats, and cougars;
however, these major predators are scarce or absent in the predominantly
agricultural landscape, where most groundhogs live. The principal
groundhog predators today are foxes, coyotes, and dogs. Groundhogs,
curiously enough, can be fierce and determined fighters in defense of
their lives and would probably be a match for any fox that was unable to
take them wholly by surprise. There are many records of a groundhog
having held a dog the size of a collie at bay and driven it off.
Many farmers consider groundhogs to be nuisance animals, because of the
vegetation that they eat, and because the piles of earth that they throw
up while digging interfere with haymaking. Groundhogs do compete on a
small scale with farmers’ cattle for food and occasionally get into
people’s vegetable gardens. But the view that groundhogs are therefore
pests, to be exterminated where possible, is nearly always a
short-sighted one which overlooks the benefits of having the animals
about.
To many hunters, particularly in eastern North America, groundhogs are
valuable game animals. Some hunters simply waste the carcass of the
animal they shoot, but a growing number are learning that fried,
roasted, or stewed groundhog can be tasty. Late summer and early fall
are the common groundhog hunting seasons. Sometimes groundhogs are
trapped for their fur, but it is generally of low value. Many are killed
on highways. Although not frequently tamed, the animals make
affectionate pets.
Finally, groundhogs are a link with the wild for people who spend more
and more time in artificial surroundings. Even just catching a fleeting
glimpse from a car of one of these dumpy mammals standing by its
roadside burrow can be a much-needed reminder of how satisfying it is to
have wild animals around.
-Thanks to Spanish Joe and his friends at
Environment Canada for this information
