For the past three days, a bat has been swooping and fluttering and looping above the pond outside my window with that distinctive short-bodied, herky-jerky flight that one normally only sees at dusk or on spooky, moon-filled Halloweens. At first, I found this bat to be spooky: daylight flight is contrary to the nature of bats and hinted of perhaps a deeper problem. Bats are notorious carriers of rabies: a friend in Panama was forced to endure the entire month-long series of rabies shots after a midnight visit from a vampire bat.
But broad daylight is a relative term, and as October's overcast segues into November, midday isn't much brighter than summer's dusk. And when I pulled out a pair of binoculars to study the errant bat more closely, I realized that he was flying with a purpose: a major insect hatch was occurring above the pond. Far from being rabid, the bat was capitalizing on a boon situation: in this season, cool night temperatures lull insects into a torpid state. The only time bugs move -- and thus are available as prey -- is during the comparatively warm daylight hours.
The bat's activities got me thinking about how animals prepare for winter. Many of the birds in our area migrate: a few stragglers -- whistling woodcocks and purring mergansers -- are still filing through on their way south, but most are long gone. Northern reptiles and amphibians hibernate. For my master's degree research, I studied one of the northernmost cypress swamps in the US. From mid October through November, the access road to the swamp was closed while the water snakes slithered up from the bowl-shaped basin into the surrounding oak highlands. I stood on that abandoned dirt road for hours surrounded by writhing masses of black bull snakes and king snakes and hog-nosed snakes and -- yeah -- fat, four-foot cottonmouths, counting and speciating and trying as hard as I could not to get overwhelmed by the macabre reality of my position.
Many mammals, too, hibernate during the winter: woodchucks and skunks and possums and some mice, bats, and -- famously -- bears. Until I watched this bat pigging out in broad daylight above the pond, I'd never really thought about the animals' preparations for hibernation, but I imagine that most of them feel an urgency to add a layer of fat before they curl up for their long winter's nap. The fat provides insulation and probably fuels what minimal body functions occur during the months of hibernation.
I've read that hibernation isn't an "all or nothing" event for many mammals. I guess some species of mice and bats are like reptiles in that they become completely torpid, existing in a virtual state of suspended animation. In other animals, however, hibernation more closely resembles a prolonged sleep. The body continues to function, albeit sluggishly, and the animal displays some consciousness of the outside world. That's the source of the whole "Groundhog Day" tradition: woodchucks often temporarily emerge from hibernation during warm breaks in winter weather.
But before this fall -- and this bat -- I had never witness a mammal other than a bear prepare itself for hibernation. I guess that's probably because in smaller animals there's nothing really out of the ordinary about their activities. A skunk filling up on wild grapes or a possum with a belly-full of grubs doesn't attract attention, and the quarter pound of grain needed to add a layer of fat to a mouse wouldn't be missed by even the most conscientious farmer.
Bears, however, are another story: they can be spectacular feeders in the fall. One year Tom shot a buck during bow season, right at dusk. After it had been hit, the buck ran a couple hundred yards into a thicket. Rather than stress the deer by following it, Tom decided to let the body cool during the night and then collect it in the morning. Unfortunately, the local bear had other plans. During the night, the bear completely devoured both haunches and one shoulder, along with most of the belly -- fully seventy pounds of meat in a handful of hours!
But my favorite fall bear was one that I met on the Hyder River in Alaska. The Hyder has a fall spawn of chum or "dog" salmon, and these fish are huge -- most fully four feet long. I was in the area during the end of the run and since Pacific salmon die after they spawn, the river was full of floating, four-foot "logs" of dead and dying salmon. Not exactly an appetizing sight -- or smell -- but the bears, both grizzlies and blacks, lined the banks and were filling up on protein for the coming winter months. One especially fat black bear had stationed himself on a boulder right in the middle of the river. I watched the bear swipe a huge paw through the current and come up with a barely flopping, already rotting salmon clutched in his fist. The bear hesitated for a full minute, studying the fish in his paw as if he was thinking, "Can I really go ahead with this and eat another twenty pounds of rotten fish?"
The hesitation lasted only for a minute. In bears, instinct will win out over intellect no matter situation the animal encounters.
Causes Louise Young Supports
articulation of indigenous rights (organization: Cultural Survival)
sustainable, renewable, and independent energy sources