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Bat Cave
Wed Mar 26, 2003
Listen in RealAudio 
Hi, I'm Bryan Yeaton for The Weather Notebook. Through a trick of thermo-dynamics the
temperature underground will roughly match the average annual temperature above ground. This
fact might not be useful in our everyday lives, but it turns out to be vital for bat
hibernation. Jeff Rice went underground in eastern Oregon on a U.S. Forest Service bat
survey.
There are about 40 to 50 thousand abandoned mines in the west, and many of
them are homes to these little guys:
BB: Looks like an evotis...
But bats need very precise temperatures for successful hibernation. Call it
the Goldylock's phenomenon. The average annual temperature needs to be just
right. If it's too warm, certain species of bats can't lower their body
temperature enough to slow their metabolism for hibernation.
BB: They tend to burn energy more rapidly and a lot of times they can't make it through the
winter.
I'm here in this mine with Dr. Burr Betts. He has done years of bat surveys
in this part of the northwest and has found that regional temperatures tend
to be a bit warm for mines to make good hibernaculums. Because of that,
mines in eastern Oregon are mostly used by bats as temporary stopovers.
BB: These mines probably provide safe roost sites. Especially if they hit a
period of bad weather. They can come in here and kind of become torpid and
wait it out until the weather gets better and then move on.
Fine if you're a bat. But no matter what the weather is outside, we'll be
happy to get back above ground. For the Weather Notebook, I'm Jeff Rice in
eastern Oregon.
The Weather Notebook is a program of the Mount Washington Observatory. We receive support by
Subaru of America and The National Science Foundation. Special sponsorship for our
cross-country weather tour comes from Davis Instruments at davisnet.com.
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