To Sleep Or Not To Sleep, That Is The Question

Nap Time For Yellowstone Bears, But Others Still Awake

By Brodie Farquhar, 12-26-06

	Photo courtesy USF&WS.

Mike Stark of the Billings Gazette has a nice article about hibernating bears today. He even has a neat art element -- an explanatory chart explaining why and how bears go into hibernation and how it is a different state from how other animals sleep away a foodless winter.

Yet there's another article, this one from the Independent in Great Britain, which reports that bears in Spain have not gone into hibernation this winter -- not when ski resorts in the Alps are snowless, glaciers are melting and Brits have spotted butterflies and bumblebees this month.

Spanish biologists have found that during mild winters (and Europe has had a series of those), some European brown bears find it "energetically worthwhile" to forage during the winter months, since food sources are not buried deep in snow.

I'd love to talk to bear and grizzly bear biologists, to learn if Yellowstone-area bears are going into hibernation like they always have, or if their hibernations are shorter, start later or end sooner. But this being the week between Christmas and New Year's, I can't find very many people just now.

Stay tuned.

UPDATE: I found this paper, which updates an earlier study by including data up to 1999. So far, the word from Yellowstone biologists is that denning hasn't changed. I'm still left wondering about the last few years, which have been notable for both heat and dryness.

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