Watching these familiar furry creatures scamper about will bring a smile to your face.
Window On Nature
By Lowell & Kaye Christie, F47246
January 2011
Although we often go hiking in search of birds and mammals, many times our best looks come through the picture window of our motorhome or just outside the windows of our home office. Since wild animals are much more observant than humans, they usually see, hear, or smell us moving around in their habitat long before we notice them. This gives these critters the opportunity to quickly leave the area or blend into the background. But when you watch these creatures from a stationary vehicle or a house, they may not even know you’re there.
Mammals are particularly difficult to watch, since most of them do their exploring at night. An exception that almost everyone knows is the tree squirrel. It is one of the easiest animals to see simply because it is active during the day and has little fear of people. If you don’t have tree squirrels in your backyard, they usually can be found in a nearby park. Our yard has a family of squirrels that entertain us all year.
Several North American species of tree squirrels exist, but they all have similar characteristics and habits. Most are named for a color (gray, red, etc.), but you should not rely on the color used in the name for identification. The gray tree squirrel, for example, comes in shades of gray, brown, black, and occasionally white. There are even Eastern and Western versions. The Western gray squirrel is the one that tries to steal food from the birdfeeders at our house, so we’ll use it as an illustration.
Like other rodents, tree squirrels have upper and lower teeth (incisors) that grow as much as 6 inches a year. But because of heavy use, the teeth constantly are being worn down, particularly by gnawing on their favorite foods: nuts and acorns. The average adult squirrel eats about a pound of food each week. During spring and summer, it adds fruit and insects to its diet.
Depending somewhat on the location, December to January marks the beginning of the mating season, and the time when the squirrels become most active. Since the sexes look identical, this is also the easiest time to tell the males from the females “” the males are the ones doing the chasing, as they jump from branch to branch and create circular racetracks around the trunks of larger trees.
If you watch during the next several months, you may notice a squirrel scrambling from place to place with bunches of leaves hanging out of its mouth. The leaves, along with sticks, are the raw materials used in making a “drey,” or nest. Squirrels actually prefer to nest in hollow tree cavities “” and their young have a higher survival rate “” but when these are unavailable, a structure similar to a bird’s nest will do. These usually are built at least 20 feet above the ground to avoid predators, but low enough that the upper tree branches provide some protection during storms. The interior is lined with fur or other soft materials, and two exits normally are created. In wintertime, when the leaves have fallen, these squirrel nests are easy to see high in the trees.
Unlike their close relatives, the ground squirrels, tree squirrels don’t hibernate; they remain active year-round. During extreme cold or rainy weather they may stay in their nests for several days at a time, but when the sun comes out again, so do the squirrels.
After breeding in late winter, the female tree squirrel gives birth in early spring to three to five young. Weighing about a half-ounce to an ounce each, the young squirrels are hairless and blind. Once they are weaned at 10 to 12 weeks, they’ll begin exploring the area around their mother’s nest.
At this time they have reached only about half of their adult weight. Western gray squirrels eventually weigh between 1.5 pounds and 2 pounds and grow to 22 inches in length. The largest of the tree squirrels is the Eastern fox squirrel, which may reach 3 pounds and 29 inches. Of course, when you see a tree squirrel, the most noticeable feature is the tail.
Our resident squirrels have tails that are about equal in length to their bodies. A squirrel tail has many uses, not the least of which is communication with other squirrels. Combined with the frequency and duration of its chirps, the position of the tail makes up part of the squirrel’s language.
The primary purpose of the tail is to provide balance as the squirrel runs and jumps through the branches high above the ground. And if it misses its mark after a long jump, the tail acts as a parachute to slow the squirrel’s descent. On a cold winter’s night, the fluffy tail also acts as a warm comforter as the squirrel curls up in its nest.
Since our local squirrels like to bury (and reclaim) acorns in the soft soil just a few steps from our sliding glass door, we’ve gotten a good look at another use for the tail during light winter rains. Rather than retreat from the showers, the hungry squirrels will stretch their tails forward over their entire body, keeping their heads dry while digging up supper.
Squirrels have a good sense of smell and usually can track down their buried stores of food. Some squirrels, before caching their acorns or nuts, will break open the shell and either lick the nut or rub it against their fur. They are adding a scent to help them locate the provisions at a later date.
Although they spend time on the ground foraging or burying acorns, the tree squirrel is designed for life in the trees. Besides an excellent sense of balance, squirrels have four sharp claws on their front feet and five on the rear that allow them to cling to any textured surface (such as bark). The back feet are “reversible,” so the rear claws can support the animal’s weight as it cautiously comes down a tree headfirst.
When on the ground, tree squirrels never walk “” they move in short hops of 10 to 20 inches. But if they sense danger, they can scamper back up a tree in a flash.
In the winter we watch the males chase the females. In spring we laugh at the young squirrels playing tag as they learn how to maneuver up and down the trees. And the rest of the year they are just friendly backyard companions. We do like squirrels.