Natural History Portrait of squirrels. |
Walking along the road, somewhere in Saint Cloud, Minnesota, the air bites its way down to my lungs on the first chilly day in October. Looking down as I walk I notice a gray mass that resembles a matted toupee discarded from a passing vehicle. But this was no toupee. Instead, it was the outcome of an unobservant driver who failed to swerve out of the path of a gray squirrel that met his match. A far too common sight on the roads from Minnesota down south to eastern Texas, and as far east as the Atlantic. This medium sized tree squirrel known in the scientific community as Sciurus carolinensis now resembles nothing but a flattened heap of fur, bones and tissues smeared across the pavement. Squirrels are mammals of the order Rodentia and the family Sciuridae. I found it hard to believe that they are cousins to rats, mice and other rodents, but after observations I began to notice similarities. Gray squirrels consist of five distinct subspecies, or races. The subspecies Sciurus carolinensis hypophaeus resides in Minnesota. Aristotle gave squirrels their first recorded name of skiouros to describe them, “skia” meaning shade and “oura” meaning tail. Thus, the full translation of skiouros means “he who sits in the shadow of his tail.” Thinking about how squirrels’ tails are sometimes just as long as their bodies, I see how he came to this perfect description. The French used the word “esquirel” to describe them and this led to the English translation of squirrel, but even the French did not properly designate a word for what I witnessed. Male or Female? I wonder, not gaining any courage to flip the squirrel over and actually look for myself. Since both sexes are roughly the same size, difficulty arises when trying to tell gray squirrel sexes apart by this comparison. When alive he (or she) could measure anywhere from 380 to 525 millimeters(mm) in length (150 to 250mm of that consisting of the bushy oura), his chubby body weighing in from 300 to 710 grams. I wonder whether the driver of the mechanical beast knew this or not. Probably not, he (or she) probably did not even notice the tiny bump as they sealed the fate for this unfortunate squirrel. Its four sets of whiskers never sensed this one coming. I can barely make them out in the furry rubble. When alive, his thin wiry whiskers were located above and below his beady eyes, on the underside of his aerodynamic head, right before his furry throat and on his tiny nose. While walking around the campus of Saint Cloud State University I notice that gray squirrels are the only animals I can count on seeing almost everyday. I watch them run, or more accurately, bounding along, leaping, as all four legs leave the ground at once, reaching speeds of up to 20 miles per hour. I watch them play tag, chasing each other around and around. I once witnessed a gray squirrel climb a tree and turn around so he faced downward, taking full advantage of his tough curved claws and ability to reverse his hind legs 180 degrees. Then, showing off his amazing strength, he let go so only his hind legs clung to the bark, and stretched, catlike, reaching towards the ground like Superman with his front legs. The image burns in my mind as I stare at the motionless carcass. Now trapped in eternal slumber, at one time this squirrel ran and stretched just like his friends that I watched days earlier. Over fifty million years ago the first gray squirrels appeared in Minnesota. I read that gray squirrels are known to plan ahead and that this contributed to their lasting presence. But he did not plan for this. Natural selection favors their ability to plan ahead to survive the harshness of a Minnesota winter, storing food in caches, and fat on their bodies. But large pieces of metal with rubber wheels did not cross Evolution’s mind. I think about this as I stare at my tire trodden friend. I wonder if he ever experienced a Minnesota winter, or if he celebrated his first birthday. Seven to eight years normally go by before death comes. However, their most fierce predator, a large metal monster that spews carbon monoxide, brings this down to a number lower than one. One year. The flattened squirrel, probably did not reach one year old. His winter coat that began growing in September, lay wasting away on the cold pavement. A few days after witnessing the aftermath of automobile versus gray squirrel, I sat on my couch gazing out the window. I could see the top of some trees that grow about 20 feet from my window. I saw something and thought are those socks? A gentle breeze meandering by could not explain the movement that I then noticed. Looking closer I noticed two gray squirrels walking the thin frail limbs of the tree like circus tight-rope walkers. I continued to watch them as they made their way to the center of the tree and noticed that one squirrel was considerably smaller than the other. A baby squirrel, I thought. But more importantly, I witnessed, for the first time in my entire life, a young gray squirrel . Gray squirrels decided that to ensure the survival of their race, they would reproduce twice a year, once between December and February, the other between May and June. The juvenile I saw probably came into this world as a product of the May to June breeding season. A typical litter contains two to three tiny squirrels, usually the summer litter produces more than the winter. The baby squirrels are born hairless and weigh between thirteen and eighteen grams, gaining an amazing forty times their birth weight before adulthood. This process usually takes eight to nine months. Judging by the size of the individual that I saw, I would guess that this squirrels saw its first day about five months ago, which fits into the summer breeding season. The eyes see their first sight, their mother, between 24 and 48 days, and fur begins to leap from their hairless bodies on about the 21st day. Female gray squirrels are sexually mature at about five and a half months, while the males do not reach sexual maturity until they are ten or eleven months old. Reproduction occurs after a mating ritual that involves the males, usually between five and ten, chasing one another around to achieve dominance. The dominant male then gets to mate with the female that they competed over. This does not insure that the dominant male’s genes get passed on, as the female mates with a few more males before the end of the day. In about eight weeks the mother unloads her burden and unleashes a few more lives. Five months later I watch the youth learn to balance itself on the tiny fingers of trees. Only the beginning for this young squirrel, these events will undoubtedly become a part of his life. If male, my new friend may soon embark on a journey that could take him anywhere from one to sixteen kilometers away from his mother’s nest when mature enough. On the other hand, females, tend to remain in the same area. Luckily for both sexes, gray squirrels are non-territorial, so they can move about without having to worry about other squirrels throwing nuts at them in anger to vacate the area. Gray squirrels tend to prefer mature woodlands as their main habitat, but we see them living quite happily in urban areas digging up yards, or stealing from the bird feeders. The most common sighting of a gray squirrel occurs when they are collecting nuts for the winter season, from oak, hickory and walnut trees. But this only accounts for a small fraction of what a squirrel will actually eat. Before teaching her juvenile to climb trees, the mother probably taught him what to eat. Most of their diet consists of plants, about 87%. This contains fruits, seeds, buds and flowers as well as pine cones. They also eat a rare amount of animal matter that includes bones, bird eggs and the occasional frog. I also witnessed a gray squirrel digging through the dumpster behind my apartment building a few weeks ago. Perhaps a delicacy to the gray squirrel, I watched as he gnawed away at a discarded apple core. With cold weather drawing near this becomes the best time to witness this squirrel behavior, because not long from now, the winter will hit Minnesota full force and food will become scarce. Also, during this time of year they pack on the pounds eating around 37% more than what they will actually use to increase their bulk for winter. I witnessed the end of the journey for one unfortunate gray squirrel. I also witnessed the early beginnings of a new journey for the tight-rope walking juvenile. Over the past months he learned a lot, but not everything. He will never learn that crucial lesson to survival, the one that human children are taught at a small age. “Do not cross the road without looking both ways first.“ I drew the conclusion that a male once animated the greasy toupee, because males roam over larger ranges than females, causing his tragic trip across a busy street. I hope the tight-rope walker is female, this would certainly decrease the chances of a mechanical murder. But if he is male, then the natural instinct to roam may become his killer. If only their natural instinct to plan ahead for long winter months could extend to “do not chance a trip across the river of rock and tar.” The gray squirrel should not count on luck or chance. A chance to celebrate their first birthdays. |