Honey emerging from den in 2009When will Ted, Honey, Lucky, and Holly den?
Time of denning is genetically programmed. We don’t know the genetic heritage of Ted and Honey and why they den around Thanksgiving or a little after, but they are consistent in doing that. Lucky was born in northern Wisconsin and dens in mid to late October.
Holly, from Arkansas, will be interesting. She likely has northern Minnesota genes from the big transfer of bears to Arkansas in the mid to late 1960’s in exchange for turkeys. She may have some Arkansas genes passed down from the few bears remaining in Arkansas back then, but it is likely she has mostly northern genes from areas where nearly all bears are in dens by the end of October. Has the nearly half century of breeding in good habitat that includes a late fall crop of acorns selected for later denning by now? Bears that den before taking advantage of the late fall acorns would be at a disadvantage in passing on their genes. They would be out-produced by bears that stay up for the acorns and get fatter and mature sooner.
Denning Contest
Another difference between Minnesota bears and native Arkansas bears might be the ability to respond to good crops of hard mast by remaining semi-active all winter and digging down into the snow like bears do in the eastern United States when winter foods are available. In Minnesota, there is no natural chance of finding significant food under the snow. We have few oaks and no hickory or beech nuts. Comiing out on warm days would be a waste of energy. The northern Minnesota trait of denning early is so ingrained that supplemental food cannot keep them out. We are at this time putting together denning data from the old Isabella study without supplemental food for comparision with denning data from Eagles Nest Community where they have supplemental food. So far, we’re not seeing much difference.
To make it more interesting, Pond Chat Mods are hosting a contest to guess when they each will den. Details are at https://apps.facebook.com/forumforpages/139730642706794/4fc32f1f-e6df-4b05-a813-a55958a3da85/0 . More coming up.
Thank you for all you do.
—Lynn Rogers, Biologist, Wildlife Research Institute and North American Bear Center