Okay, I'm cheating just a bit on this. This is not a December photo. It was actually taken in May in Alberta Canada. However, it looks like winter -------------------- doesn't it?
Black bears do not hibernate like Brown Bears (Grizzlies, Kodiak) or Polar Bears. However there are metabolic changes that allow black bears to remain dormant for months without eating, drinking, urinating, or defecating. Biologists have redefined mammalian hibernation as "specialized, seasonal reduction in metabolism concurrent with scarce food and cold weather". Under this definition Black Bears qualify. However, if the winter is mild enough, they may wake up and forage for food.
Black bears enter their dens in October and November. Prior to that time, they can put on up to 30 pounds of body fat. Hibernation in black bears typically lasts 3–5 months. During this time, their heart rate drops from 40–50 beats per minute to 8 beats per minute. Unlike Brown Bears and Polar Bears, their body temperature does not drop significantly and they remain somewhat alert and active. A hormone is released into their systems, to suppress appetite. Because they do not urinate or defecate during dormancy, the nitrogen waste from the their body is biochemically recycled back into their proteins. This also serves the purpose of preventing muscle loss, as the process uses the waste products to build muscle during the long periods of inactivity. Females give birth in February and nurture their cubs until the snow melts. During winter, black bears consume up to 40% of their body weight. When they awake, they seek carrion from winter-killed animals and the new growth of plants and trees. In mountainous areas, they seek southerly slopes at lower elevations for forage and move to northerly and easterly slopes at higher elevations as summer progresses.
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| Black Bear in Tree, Alberta |
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