The arrival of Autumn brings with it increased activity among wildlife as most species have behaviors that kick-in this time of year. Some are preparing for hibernation or deep sleep, others are bulking up for a long migration and, queerly enough, there are a few who make Autumn their mating season. And then we have some “oddballs” for whom Winter presents other challenges for which they must prepare. Let’s see who is doing what.
True Hibernators: these are primarily reptiles and amphibians, along with many insects and a few mammals. Most activity surrounds eating as critters try to internally stockpile nutrition and fats to see them through the long, deep sleep. Assisting in this endeavor is a significantly lowered metabolism once in hibernation, which goes a long way in helping these animals make it through to Spring. Another autumnal activity of true hibernators is seeking out appropriate denning sites that will help protect them from the elements. Reptiles and amphibians will burrow beneath leaf material, the ground or even in the muck at the bottom of ponds to live out the Winter. Some insects do the same or escape behind tree bark or deep within logs in hopes of escaping the deep freeze. For the hibernating mammals (in Western New York this includes the Woodchuck, Jumping Mouse and Little Brown Bat), the four leggeds take to the underground while the bats usually colonize in caves together for the long Winter’s rest.
Deep Sleepers: For this group of mammals, we see a dramatic decrease in activity during the long months of Winter. For the deep sleeper (which includes Raccoons, Chipmunks, Black Bears and Skunks here in Western New York), fattening up and/or caching food is a fundamental Autumn behavior. But unlike the true hibernators, the metabolic rate of deep sleepers falls only marginally – enough to conserve vital energy but not so sharp that they are unable to quickly arouse if weather warms or a threat is perceived. And as is the case with some female Black Bears, they must maintain a high enough metabolic rate to give birth while in deep sleep, having entered the Winter den pregnant.
Migrators: By and large, this group encompasses mostly avian species, however there are a number of insects and bats that will make a distant journey in order to live-out the Winter. In anticipation of travel, we see increased feeding, particularly on late Summer flowers, berries (such as elders) and seeds, along with flocking or swarming as preparatory behaviors.
Reproduction: For our Cervid friends, Autumn means mating and we see all kinds of activities associated with reproduction. Vocalizations, battles for mating privileges and an overall higher level of energy are quite common, particularly among the males. As for birds, American Goldfinch parents are in the final phase of teaching their fledges the ropes, having put off nesting until the second half of Summer to correspond with the blooming of thistle and other important late flowering plants upon which they depend. Owls and Eagles will mate over Winter so if they are not already spoken for, late Summer and Autumn are perfect times to “hook up” with a partner.
The Oddballs: In this group, I include the Beaver, Opossum and Porcupine. Beaver who den in lodges must prepare for the potential of pond freeze-over. Toward that end, Beaver families busy themselves eating the last of the Summer greens while collecting suitable twigs and branches which will be cached near the submerged lodge entrance. This “subterranean brush pile” allows them to swim out, grab dinner then head back into the lodge for a warm, dry and comfortable meal. As for Opossums, although they do not hibernate nor sleep deeply, these marsupials are subject to frost bite on tails, ears and other thinly furred areas so often wait out long cold spells in their dens. So it is not unusual for the Opossum to increase its Autumn feeding activities in anticipation of periods of fasting over Winter. The Porcupine, while not a deep sleeper, does stay much closer to the den during Winter and will sleep for longer periods. Therefore, some added feeding is quite common during Autumn to supplement energy reserves.
All this preparatory behavior gives we humans a better chance of seeing wildlife in action during Autumn. At the same time, it also means we need to be hyper-vigilant as we travel along roads and highways so to avoid any disastrous encounters with our busier than usual wild friends. So enjoy watching the Flurry of Fall but remember to keep a sharp eye out and a lighter foot on the pedal while driving during this beautiful and energetic season.