When do bears select their dens?
September 19, 2010 – 9:32 PM CDT
We wonder when bears select their dens. Years ago, June worked for over half an hour enlarging a den on July 19 and didn’t come back to it until she was ready to go in for the winter. Tonight Braveheart seems to be at the dug den she’s been hovering around since last night. We stumbled upon this den on June 30 when we were radio-locating Braveheart to change the batteries in her GPS unit. The den showed signs of recent activity and we suspected Braveheart had been checking it out. Fortunately, we GPSed the location of the den and can now compare it to the readings we are getting from Braveheart’s collar—a near perfect match.
We’ve seen bears checking out potential den spots all spring and summer as they forage—especially pregnant females. Years ago, Big Mac roamed 126 miles outside his usual range starting in July and then came directly back to a den in October like he already knew exactly where he wanted to den up for the winter. The den just fit his 450-pound body. We knew he’d never used that den before because we had checked it each winter ever since another 450-pound bear used it six years earlier.
When we changed the batteries in Ursula’s GPS unit tonight we found grit under the flap of the case that holds the GPS unit. We suspect she’s been doing some den work.
Lily and Hope moved nearly two miles southwest overnight, stayed put all day. They were observed feeding on large-leaf aster leaves. Earlier tonight they moved further south but they appear to be bedded again now. We dearly want to put a Den Cam in their den. We hope they aren’t too hard on us with the den location. We had also wanted to put a Den Cam in June’s den, but she denned where it would be impossible to get to her for long periods, which could be bad if something went wrong with the equipment. We’d all be without a picture for a month or so.
Whatever happens, though, we have to get a Den Cam in Lily’s den. We have to know how the story comes out with Hope being in there when Lily gives birth and nurses cubs.
We’ve heard several questions about the Black Bear Boxes, the Educational Outreach people are making. These will be available for rent by schools eventually. Several people are working on getting the materials together. Others designed the very well received logo to go on the boxes. There is so much interest in having a modified version of the logo with its beautiful silhouette of a mother and cub (Lily and Hope?) for a decal and a bumper sticker that the makers and the retail people will probably collaborate to make them available. The simple silhouettes with a background that makes them look like they are back-lighted by a setting sun are beautiful.
We’d love to give individual credit on so many things, but we hesitate to start that because it is too easy to miss other deserving people. We are thankful to you as a talented group who have done so much, stepping up where you see needs and making your actions labors of love. It shows in so many things, like your excellent letters to officials. The list could go on. There is a lot going on behind the scenes. Things are coming together on one thing and another, thanks to you.
Thank you for all you do.
—Lynn Rogers and Sue Mansfield, Biologist, Wildlife Research Institute and North American Bear Center