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Research study sheds light on winter naps


Submitted photo

PROFESSOR TIM Ginnett attaches a radio collar to a black bear with four cubs near Mellen, Wis., as part of a continuing study.

Hello friends:

This week’s column is brought to you thanks to a bear research study conducted for the past 30 years in Ashland, Sawyer and Bayfield Counties. It is run by Tim Ginnett, an associate professor at the College of Natural Resources at the University of Wisconsin-Stevens Point.

Sunday, March 16

High 25, low minus 14

I met Margaret “Maggie” Heino back in the early 1990s, when professor Ray Anderson was running this study and also figuring out a way to get elk introduced into Wisconsin. All it took was one call to my friend Maggie, who is the chief logistics person for this operation, and I was back in the bear dens.

Today’s first sow was located south of Mellen, and she was discovered on private land by Jake Baldauf while deer hunting last fall. Actually, Jake first discovered where the den was being created and dug into the ground at a somewhat horizontal angle over eight feet deep.

Once the snow fell, Jake hiked into this stand of balsam trees and re-checked the den which, with an entrance width of 28 inches, was covered for the most part with deep snow. The tell-tale sign there was a bear inside was a “blow hole” where the sow’s breathing (and cubs’) was keeping a small entrance from being snowed over.

Today I hiked in with several volunteers on the study, some members of the Baldauf family, and Tim Ginnett.

The one mistake that I made was having forgotten my snowshoes in my living room and having extreme difficulty making it to the den.

First, everyone is very quiet and listens; next the sound of cubs is heard.

Next, a volunteer shovels out the den entrance so Bruce Prentice, a retired Ashland teacher, is held by his feet or jacket as he assesses the situation.

Though there are very few volunteers consumed by sleeping bears, the job of assessing the den by looking into it and being within inches of a bear’s face takes a brave man or woman.

Next, the bear’s weight is estimated and she is anesthetized, which lasts for about 90 minutes. First the cubs, born around Jan. 1, are pulled from the den and each one put into a jacket to keep it warm.

There were four cubs with this 7- to 9-year-old sow, and it is believed that she had four cubs two years ago, as well.

Each cub was weighed (about 7 pounds each), sexed and their hair was measured. Three of the cubs were males.

Next, the very large job of removing the female from the den was done. Four strong men did this task and it was not easy. The sow was weighed and she came in at 255 pounds, which is a very nice size for a sow this late in the winter.

Interesting fact! The sow had dug her den 100 feet from a wetland. Wetlands thaw out first when spring arrives and have green grass. When the sow wakes up, she will be a vegetarian and will make short trips to the wetlands alone to feed and drink. Next, she will bring the cubs for short trips, then the den will be abandoned.

I watched as this crew of six people worked flawlessly, measuring the sow, taking her temperature, and putting on her radio collar, which Maggie will use through telemetry to record her movements.

I learned nature does not decide until November when the sow enters her den if she is in good enough shape to give birth to cubs or absorb them.

I learned males are seldom radio-collared because of their nomadic lifestyles. It would be difficult to locate them once they leave the den (a female has a much smaller home range.)

I realized after meeting the Baldaufs, hearing Jake’s story, and then talking with Tim Ginnett, just how important it is if you know of an active bear den on your land, to inform the right people, and give access so this type of research can have its opening phase.

Wisconsin’s bear population is growing, as is the black bears’ range across the state.

One way to get an idea as to the health of our bears, as well as their numbers, is through telemetry and den studies.

When the den was closed, it was done by putting balsam boughs over the entrance and then a bit of tobacco was thrown over it to honor the five bears inside of it.

Love my job!


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