Friday, January 11, 2013

The Truth About Bears: "Hibernation"

 It is a common misconception that bears hibernate during the winter. While bears tend to slow down during the winter, they are not true hibernators. However, black bears, grizzly bears, and brown bears do go into a deep sleep during the winter months, known as torpor.

Hibernation is when animals "sleep" through the winter. During this sleep, the animals will not wake up when they hear a loud noise or even if they are moved or touched. While in torpor, the animal can wake up quickly and easily. During true hibernation, the animal's body temperature drops to match the outside temperature, and their heart rate and rate of breathing slows down. During the bears' dormant state, or torpor, their heart rate is extremely low but their body temperature is relatively high, and they won't eat or release bodily waste. Animals hibernate as a way to adapt to their surroundings. They have to be able to survive the cold weather. They hibernate to escape the cold and because food is scarce.

To get ready for hibernation, animals will eat more than usual during the fall to store up body fat. During hibernation and torpor, they will use up this extra body fat to live off of while not losing any muscle. This allows the animal to come out of thinner, but still as strong as it was before winter. They will get their dens ready for hibernation during the late fall. The bears of IEAS usually get ready in late November depending on when the cold weather hits. The black bears in Bear Orphanage have taken full advantage of the caves we offer, but there are those who still dig a den.

For the bears of IEAS, they react differently during the winter months. All of the bears, grizzlies and blacks, store up during the fall, increasing their body fat. The four Grizzly bears will store up during the fall as normal, and once it really cools down (usually late November to mid December depending on the year) they will den up only to come out during the warmer days. When they do come out, it's only for a short bit, and they are not very active during that time. They are quick to retreat back to their cave. The black bears slow down and spend most of the time in their dens or caves; however, they still snack a little throughout the winter. Dakar and Meyote did become dormant and actually dug their own den during their first winter in Bear Orphanage, but have been a little more active during the winter seasons since then. We believe this is due to the other bears residing in Bear Orphanage. Their first year, it was just the two of them. Now, there are 8 bears residing with Dakar and Meyote!

1 comment:

  1. Interesting read, I was researching this subject earlier, although not just hibernation with bears, but on all mammals including dormice and bats.

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