CHEEKTOWAGA, NY - As the temperature drops and light levels diminish in the fall, it marks the beginning of one the most complex adaptations made by life in the natural world: that of hibernation.
For those animals that can't migrate from frozen habitat, this process is essential. There are many creatures that go through this annual dormancy , although the extent of hibernation varies widely.
Kristen Rosenburg is an Environmental Educator at Reinstein Woods Nature Preserve. "In New York state there's three true hibernators: the woodchuck, jumping mice, and cave bats like the little brown bat. And then there's some animals considered deep sleepers like black bears and chipmunks. But there are other animals that hibernate, like reptiles and amphibians -- turtles, snakes and frogs."
Brittany Rowan, also an Environmental Educator at Reinstein, adds: "They'll drop their core body temperature, they'll decrease their respiration rate, their metabolism will slow, and it's about as close to death as you can come."
Possibly the most fascinating of the hibernators are black bears. Once thought to be true hibernators that remain dormant throughout the winter it is now known that they rouse from their deep slumber periodically. While they are in their den, Rosenburg says that some pretty incredible things are going on. "They give birth during that wintertime period, and they're not one of the true hibernators, so obviously they're rousing to give birth."
Rowan continues: "Even though the mother bear might be a little bit sluggish, she still nourishes them, and for the rest of the winter they'll live off her milk and grow some fur so they can stay warm, as well."
During their hibernation, bears don't eat or drink, but they neither dehydrate nor are they poisoned by their own waste. "They don't dehydrate because they don't get up to urinate or defecate in the winter," says Rowan. "So there's no need to flush toxins out of their system. With humans, we can't do that because urea is toxic to us. But the bears have this fascinating ability to change urea into a non-toxic substance, so it can stay in their body without killing them."
Rosenburg tells 2 The Outdoors that among the true hibernators that stay dormant all through the winter are bats. "In terms of bats hibernating, it is in response to a lack of food. Bats are primarily eating insects; there's no insects or moths flying around (in winter) so the bats are hibernating as a way to survive."
Unfortunately a number of bat species across North America are being attacked by a fungus that affects them during hibernation, when they are most vulnerable. The disease, known as White Nose Syndrome, has killed several million bats since its discovery in Central New York in 2006. It could push many species to the brink of extinction.
"The White Nose Syndrome wakes them up out of hibernation, which is costly in terms of energy," Rowan said. "Once they're awake they have to live off their fat reserves, which gets depleted quite quickly, because they're not able to maintain a high body temperature. It takes up too much energy and that's why they die."
And then there is the human animal, which has adapted artificial means to survive the cold. But, Rowan says, we still may share the urge to hibernate with our animal brethren.
"I think everybody feels a little sluggish in the wintertime, whether that's cold temperature or not enough daylight to tell our brains to be awake, I think we all have that innate desire to hibernate."