Ecology

Squirrels

Anne Gageby
Strawberry Hill Nature Preserve

(10/2024) Raise your hand if you have a bird feeder. Give it a wave if you’ve ever dealt with squirrels getting into said bird feeder. It seems like there are a hundred ways of preventing the pesky rodents from stealing bird food and just as many ways squirrels find their way in anyway. Squirrels are sneaky, tricky, and snap-quick at evading predators. They’re also kind of cute.

Sometimes, when I’m out on the trails, I’ll stop and watch as these small to medium-sized rodents scurry along the forest floor or across branches. It’s fascinating to watch them bolt then stop to look around and swish their tails, before bolting again as if spooked by the dappled sunlight or maybe their own imaginations.

Not that squirrels don’t have real predators. Hawks, foxes, snakes, and owls are the most common predators though they are most successful when squirrels are young. As adults, all squirrels are incredibly adept at evasive changes in direction and disappearing. Gray squirrels are especially quick, much faster than reds. Unlike many other animals, adult squirrel populations are not usually impacted by predators as food accessibility is a bigger determining factor. A bad year makes a more noticeable impact on population density.

Grey squirrels consume mast such as hickory nuts, beechnuts, walnuts, and acorns. The quintessential image of a squirrel is of one holding or hiding a nut. They’re famous for burying extras and inadvertently growing a forest. But they eat other foods, too. Berries, mushrooms, corn germ, insects, and amphibians round out squirrels’ diets. Yes, squirrels are technically opportunistic feeders that will consume animal parts alongside the more typical nuts and fruits. Foods such as bones, bird eggs, and even dead animals are consumed when season and availability call for it.

As for water, squirrels consume high-moisture foods such as buds and flowers though gray squirrels will drink from ground-water sources as needed. They’ve been known to scratch at maple trees until sap flows and indulge in a tasty drink. Hobbyist maple sugarers can often spot the little rascals sneaking drinks from winter maple taps. Work smarter, not harder, after all.

Pennsylvania is home to four native arboreal, or tree, squirrel species – the gray, fox, red, and flying squirrels. The gray is the most common species found in Pennsylvania. Squirrels are members of the family Sciuridae; a family that includes the previously mentioned tree squirrels, ground squirrels including chipmunks, and flying squirrels. They have keen senses of hearing and smell. All species are most active during the day except for flying squirrels which are nocturnal. Unlike many animals, these interesting little rodents only see in black and white. Like many other mammals, however, they’re born hairless and blind and are dependent upon their mothers for the first two months of life. Upon maturation, squirrels become incredibly agile and able to care for themselves.

They’re one of the only mammals that can descend a tree upside down due to two unique adaptations. First, their tiny claws are hook-shaped and are able to grab tree bark with ease. Second, their wrists and ankles can turn 180 degrees which allows them to climb, hang, and flee as needed, no matter the direction. They are among the most skilled tree-climbers in Pennsylvania. They have the added advantage of having powerful abdominal and back muscles which make climbing a breeze. And even non-flying squirrels have the ability to jump about seven feet at a time as they move from branch to branch.

Interestingly, the northern flying squirrel doesn’t actually fly. It travels by gliding, reaching an average distance of about 65 feet. They can also reach eight miles per hour in ground speed. Unfortunately, the northern flying squirrel is listed as endangered here in Pennsylvania as it’s becoming more and more rare. Its home range is now limited to northern conifer forests. The smaller southern flying squirrel is not endangered as is more widespread in both habitat and range. Fortunately, the northern flying squirrel is considered secure nationally so that’s a positive checkmark for the species.

If you’ve ever seen a squirrel up close, you might notice how gray squirrels are only partly gray. They are often silver-gray on top and off-white on their bellies. There are usually rust-colored markings on their sides that add interesting visual contrast. Like many creatures, albino squirrels do occur though they are considerably more rare than melanistic squirrels. In fact, dark gray-black to jet-black squirrels are fairly common.

Their long, bushy tails are iconic and useful. They aide squirrels in maintaining body heat when temperatures drop by acting like a fluffy blanket to curl up under. They help keep rain and snow from the main body and when necessary, can signal to other squirrels if danger is close by. Probably the coolest use of squirrel tails is parachuting. Squirrels are just as adept at landing as they are jumping. That’s because they can flatten their bodies and use their tails like a parachute to help slow their fall. Squirrels are fantastic showmen when it comes to feats of falling.

Just today I was out on the trail and watched a gray jump between branches. He lost his balance just enough to slide sideways before catching himself and scurrying up the tree trunk. It was pretty impressive and definitely took skill. I continued to watch him as he paused, looked around, and climbed back down to his previous spot. It made me wonder what exactly was going through his mind. Do squirrels have thoughts and if so, do they operate at the same warp speed as the rest of them? Better yet, do they understand how interesting they are to watch as they scramble across yards, backtrack, and bound playfully around as if physically unable to sit still? They’re adorable and fascinating. Although, I’m quite certain birds trying to get to feeders would disagree.

Anne Gageby is the Environmental Education Manager of the Strawberry Hill Foundation. Strawberry Hill inspires stewardship of our natural world by
connecting the community with educational opportunities.
 Learn more by visiting StrawberryHill.org.