By April Overall
Have you ever woken up from a long afternoon nap and found yourself wondering what day it was? A little snooze can set your world spinning for a minute or two. Try months of slumber. So how do animals know when they should catch some more zzzzs and when they should stretch their legs? And what do they do once they've received their wake up call?
Coming Back From the Dead
While many amphibians will seek out a watery place to rest for the winter, others will seek out a spot to hibernate on land. The American Toad, for example, will scramble into soil, below the frost level to take a winter snooze. The Spring Peeper looks out for crevices in wood or rocks or will dig into leaf litter. While their resting places shelter them through autumn, when old man winter arrives these amphibians freeze. In fact, their breathing comes to a halt and their heart stops beating. Are they dead? Not quite! As the temperatures warm in spring, their bodies heat up, their hearts begin to pitter patter and they take a breath of air once more.
Breaking an Embrace
Many insects use their bodies to conserve heat through the winter. Honeybees, for instance, will spend the cold months cuddling in order to keep the queen and young bees alive, thereby saving the colony. Reptiles like the Garter Snake will travel far and wide to find a suitable hibernaculum - a safe, dry spot to rest through the winter. Once they've found a proper hibernaculum, they snuggle up, using their bodies to keep warm. Since they are cold-blooded, their bodies always remain at the same temperature as the air around them. Therefore, they rely on a warming climate to nudge them out of their sleep.
Mammals across Canada spend the autumn months fattening up to prepare for the cold harsh winter. It's a good thing they do since food is scarce! Bears like the Black Bear and the Grizzly Bear can lose nearly 25 per cent of their weight in a single winter season. They survive by reducing their heart rates, a significant drop in body temperature (by up to 10 degrees) and slowing their metabolism. When spring arrives, they have particularly rumbly tummies and they spend long days seeking out food to bulk up again.
Rising From the Ground
Some aquatic animals swim to the very bottom of lakes and ponds to hibernate in their murky depths. Painted Turtles and Leopard Frogs, for example, bury themselves in the bottom of lakes and ponds, relying on the mud's oxygen supply. Come spring, when the water begins to warm, they swim to the surface for their first breath.
Waking too Soon
An early wakeup call can be very harmful for animals. The food they need to eat after months of hibernation isn’t always readily available and they can expend a lot of energy looking for it. Some of our favourite bat species have been struggling with an early wake up call in recent years - all due to a disease called White-nose Syndrome (WNS). The Little Brown Myotis, the Northern Myotis and the Tri-coloured Bat have been listed under the Species at Risk Act as Endangered because of the disease. A fungus grows on the exposed skin of bats as they hibernate during the winter in caves and mines. The cool temperatures of these hibernating sites allows the fungus to grow and spread throughout the site and on the bats themselves. The disease shows up as a fuzzy white substance on their ears, wings and muzzles. However, this isn’t the only damage this fungus causes. Internally the bat’s muscle tissues and blood vessels are affected and the bats end up dying as a result of dehydration (they lose water and electrolytes from their wings) and starvation (they wake up from hibernation more frequently using their fat reserves which can’t be replaced as flying insects are not available). The results of WNS are devastating with some Canadian populations down by 90 percent in only three years.