No wonder animals hibernate. You wake up a dark November morning only to find out it's pouring rain, even though the thermometer reads 30 degrees. It's enough to make anyone want to go back between the flannel sheets and set the alarm clock for May.
And this gloomy time of year is just when many animals start to hibernate. But I'm thinking of bats, and not of the stereotypical hibernating bear. Bats follow a similar hibernation pattern and have settled into their winter routine right about now.
Not all of Vermont's nine species of bats hibernate. Some migrate to warmer climates. Others do both: migrate south, then hibernate for part of the winter there.
But Vermont's most frequently seen bats -- the two species that end up roosting in eaves and attics -- both do hibernate in winter.
The big brown bat is the less common and the hardier of the two. If you see a bat fluttering through the sky on a warm winter evening, it's probably a big brown bat.
Big brown bats are also more diverse in their hibernating patterns where they roosted all summer: in a barn, an attic or on a tree under some bark. Or they may move into a cave to hibernate, often joining their more common relative, the little brown bat, there.
Little brown bats, on the other hand, are pretty consistent in their hibernating habits. Sometime in October or November they will move into a cave of some sort, often joined by hundreds or thousands of other little brown bats (plus other bat species, they are not elitists) and begin to hibernate.
Hibernation allows the bats (which truly are delicate creatures) to survive our brutal Vermont winters, but since the beginning of humankind's world domination, it has also put them in great danger.
During hibernation a bat's metabolism slows way down, allowing it to live on its energy reserves through the winter until the flying insects it dines on, mostly mosquitoes and moths, come into season again.
Unlike the woodchuck, which seems to go into some kind of coma when it hibernates and can't be roused, bats will and do come out of hibernation when disturbed during the winter. The disturbance can be as minor as a person entering the cave where they are hibernating.
Waking out of hibernation causes the bats to burn up days and days worth of energy. If they pick up and move to another site, which they often do when disturbed, they use even more energy. A bat that is disturbed as few as two or three times in a single winter can burn up all its energy reserves and die.
Most people who disturb bats while they are hibernating do it accidently. Cave explorers, hikers and teenagers looking for an adult-free place to party are usually not aware that their activities can be fatal to the bats they stumble upon.
Bat conservation advocates have been quite successful in educating cave exploring clubs and getting them to curtail winter activities in caves where bats hibernate. The teenagers, needless to say, are harder to reach.
Unfortunately, the large concentration of bats also attract vandals who do mean them harm.
Here in Vermont, it's hard to find more than a few hundred bats in a single cave. It's nothing like the caves of Texas or New Mexico where millions of bats live in one cave. But those few hundred bats can represent a significant part of the state's bat population.
People who hate bats don't seem to realize they are nature's own bug zapper. And bats actually do a better job. A single little brown bat can clear the air of thousands of mosquitoes in a single night. It goes to work every night through the summer. No electric outlet required.
Madeline Bodin writes from The Vermont Institute of Natural Science in Woodstock, Vt.
If
you lead a good life, eat all your vegetables and say all your
prayers, when you die you'll go to Vermont.
The Perils of a Long Winter's Sleeep
