FWP OUTDOOR EXTRA
THIS IS 'HIBERNATION IS COMING' SEASON FOR BEARS
By Kim Annis, Montana Fish, Wildlife & Parks Bear Biologist in Libby
Some people say that there are only two seasons in Montana: winter’s coming and winter’s here. For bears those two seasons are: hibernation’s coming and hibernation’s here.
In anticipation of hibernation, bears enter a "food-eating frenzy" known as hyperphagia this time of year. In hyperphagia, a bear may eat 20,000 calories and gain several pounds, or more, per day. Adult bears can pile on more than 100 pounds before denning.
To that end, berries and fruits high in sugar are an important fall foods. This was a good berry year in the Cabinet -Yaak and southern Rocky Mountains and not so good in the Northern Rockies along the Eastern Front. Fruits, grasses, forbes and meat, usually the remains of hunters killed animals, are also central to a bear's fall diet.
While preparing for hibernation, bears are easily tempted to score calories where apples or plums are left on or under trees, or where livestock feed, dog food, garbage and other foods are left outdoors and accessible. Do bears, and your neighbors, a service by securely storing all potential bear attractants, including bird feeders, until after bears hibernate.
Bears den up when winter begins in earnest and their natural foods disappear—sometime between October and December. As long as there is ample food they stay awake, so when bears hibernate varies year to year.
In general, grizzlies prefer to den at 6,000 feet or higher. They use their long front claws and powerful front legs to dig a den in the ground, usually selecting remote areas where the snow will be deepest.
Black bears typically den at much lower elevations and often use "ready-made" dens within tree cavities, burrows, and rock-crevices with openings that are just large enough for a bear to squeeze through. Last fall a black bear near the Kootenai River created fine den under an old log jam along a stream.
A bear den is small, with just enough room to turn around in, to minimize heat loss. While a black bear will reuse a ready-made den, grizzly bears typically dig new dens, even though they may den in the same area as in winters past.
Researchers say bears have a very evolved hibernation capability. Bears do not eat, drink, exercise or excrete any body wastes during their five- to six-month slumber. Instead, they are uniquely able to convert toxic body wastes, and break down muscle and organ tissue to supply protein. Their fat breaks down to supply water and calories. Amazingly, a bear's muscle mass and tissues do not atrophy in this process.
Adult male bears den just as they spend most of their lives, alone.
Female grizzly bears and their offspring typically den together for three winters: the winter the cubs were born and two consecutive winters after that. The female separates herself from her offspring when they are two and a half years old and she is ready to breed again.
Female black bears usually part from cubs that are a year and a half old. Sometimes young siblings will den together the first winter after they separate from their mother, though unrelated bears will not hibernate in the same den.
For more on Montana's bears, including photos and instructions on how to bear-proof a residence, visit the Montana Fish, Wildlife & Parks web site at fwp.mt.gov . Look on the Wild Things page under Hot Topics for the Be Bear Aware section.
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THIS IS 'HIBERNATION IS COMING' SEASON FOR BEARS
By Kim Annis, Montana Fish, Wildlife & Parks Bear Biologist in Libby
Some people say that there are only two seasons in Montana: winter’s coming and winter’s here. For bears those two seasons are: hibernation’s coming and hibernation’s here.
In anticipation of hibernation, bears enter a "food-eating frenzy" known as hyperphagia this time of year. In hyperphagia, a bear may eat 20,000 calories and gain several pounds, or more, per day. Adult bears can pile on more than 100 pounds before denning.
To that end, berries and fruits high in sugar are an important fall foods. This was a good berry year in the Cabinet -Yaak and southern Rocky Mountains and not so good in the Northern Rockies along the Eastern Front. Fruits, grasses, forbes and meat, usually the remains of hunters killed animals, are also central to a bear's fall diet.
While preparing for hibernation, bears are easily tempted to score calories where apples or plums are left on or under trees, or where livestock feed, dog food, garbage and other foods are left outdoors and accessible. Do bears, and your neighbors, a service by securely storing all potential bear attractants, including bird feeders, until after bears hibernate.
Bears den up when winter begins in earnest and their natural foods disappear—sometime between October and December. As long as there is ample food they stay awake, so when bears hibernate varies year to year.
In general, grizzlies prefer to den at 6,000 feet or higher. They use their long front claws and powerful front legs to dig a den in the ground, usually selecting remote areas where the snow will be deepest.
Black bears typically den at much lower elevations and often use "ready-made" dens within tree cavities, burrows, and rock-crevices with openings that are just large enough for a bear to squeeze through. Last fall a black bear near the Kootenai River created fine den under an old log jam along a stream.
A bear den is small, with just enough room to turn around in, to minimize heat loss. While a black bear will reuse a ready-made den, grizzly bears typically dig new dens, even though they may den in the same area as in winters past.
Researchers say bears have a very evolved hibernation capability. Bears do not eat, drink, exercise or excrete any body wastes during their five- to six-month slumber. Instead, they are uniquely able to convert toxic body wastes, and break down muscle and organ tissue to supply protein. Their fat breaks down to supply water and calories. Amazingly, a bear's muscle mass and tissues do not atrophy in this process.
Adult male bears den just as they spend most of their lives, alone.
Female grizzly bears and their offspring typically den together for three winters: the winter the cubs were born and two consecutive winters after that. The female separates herself from her offspring when they are two and a half years old and she is ready to breed again.
Female black bears usually part from cubs that are a year and a half old. Sometimes young siblings will den together the first winter after they separate from their mother, though unrelated bears will not hibernate in the same den.
For more on Montana's bears, including photos and instructions on how to bear-proof a residence, visit the Montana Fish, Wildlife & Parks web site at fwp.mt.gov . Look on the Wild Things page under Hot Topics for the Be Bear Aware section.
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