Take Me Outside: Squirrels act as arboreal acrobats

A gray squirrel holds an acorn and looks down from a branch.

At this time of year, many people enjoy feeding birds. Inevitably, if you put up bird feeders, you'll also end up feeding squirrels. While this can be frustrating, rather than spending energy and funds on "squirrel proofing" a feeding station, why not give in to squirrel tenacity and enjoy some of the marvels of these tree rodents?

In this part of the country, we have five resident squirrel species. Chipmunks, our only ground squirrel, are dormant in underground burrows at this time of year. Two species of flying squirrels are nocturnal and rarely seen. The common tree squirrels include the eastern gray squirrel and the smaller red squirrel. Both are arboreal and extremely adept at tree climbing (and birdfeeder jumping). Beyond that, they have surprisingly different habits.

Gray squirrels eat acorns, hickory nuts, beechnuts, butternuts and walnuts. They like to live in forests with nut-bearing trees. Red squirrels will eat nuts if they find them, but more commonly they feed on seeds from conifers, such as pine, spruce, fir and hemlock. So, red squirrels are usually found in forests dominated by evergreens.

They also gather, store and consume their food in different ways. When a gray squirrel finds a nut, the squirrel will either eat it immediately or bury it, marking the spot with its scent. Later, perhaps during the winter when the place is concealed under snow, the squirrel may use its sense of smell to find it, dig up the nut and eat it. Or it may not. Another squirrel may have found it first, and many nuts are never found — so squirrels inadvertently plant trees, ensuring a food source for future squirrel generations.

Red squirrels have a different strategy. They cache their food in a hollow tree or underground, sometimes accumulating bushels of intact pine cones all in one place. When they retrieve the cones, they bring them to a feeding stump or log and nibble on a cone the way people munch on corn on the cob. A midden, or large pile of cone scales and cores, left on a stump is a sure sign of a red squirrel dinner table.

Both squirrels also feed on softer plant material. Berries and tree buds become part of their diet during warmer weather. A wild apple found in the crotch of a tree or a mushroom speared onto a branch to dry are clues that a squirrel is trying to vary its diet.

Surprisingly, these rodents are not exclusively vegetarians. Both are known to eat birds' eggs and baby birds. Gray squirrels will eat insects, caterpillars and even woodland frogs. Red squirrels may consume smaller mammals, like mice or voles.

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On the flip side of the consumption equation, squirrels are eaten by many larger animals like foxes, coyotes, bobcats, fishers and birds of prey. They are wary and have amazing survival skills.

One of their best defenses is climbing a tree and leaping from branch to branch with the precision of a circus performer. What seems like a random romp to us is actually a carefully chosen route. Squirrels lay out and follow (probably by scent) familiar pathways through the branches, and those paths give them a distinct advantage of knowing where to go in a hurry.

Familiarity with territory also helps them survive. Red squirrels are extremely defensive of their home range, food caches and dens. They use a wide variety of sounds, tail waving and foot stomping to let intruders know they are not welcome.

Gray squirrels, who are less particular, are known to den communally in the winter (males and juveniles) and have overlapping home ranges. Only when the female has young in a nest does she defend her space.

When gray squirrels have conflicts, they usually only involve a friendly chase, avoiding any real aggression. You may see a chase in the February breeding season. If you see a train of gray squirrels scampering across the ground, up and around a tree trunk, it is likely a female being pursued by one or more males, hoping to pass on their genes.

If one of them is successful, in about six weeks there will be a new generation of squirrels to observe and learn from as they share our "bird" feeders.