Never underestimate the gray squirrel
Consider the Eastern Gray Squirrel. I certainly do often enough, particularly when a representative of the species is hanging poised in a delicate three-point stance, deftly trumping my allegedly squirrel-proof bird feeder. Every now and then it will sit back to savor a particularly tasty morsel of sunflower seed and fix me with a beady-eyed look of disdain as if to say simply, “Hah!”
So how does a creature with a brain the size of a grape possess the mind of a safe-cracking genius? For the answer to this and other questions on the subject of Sciurus carolinensis, we turn to Peter Smallwood, associate professor of biology at the University of Richmond, who has made a study—quite a few in fact—of the gray squirrel. And if there is one lesson that several decades on the job has taught him, it is this: never underestimate a squirrel. “They usually know more than you think they do.”
One of the first things Smallwood discovered is that in the fall, when gray squirrels are gathering acorns, their choice of which to eat immediately and which to bury for later consumption isn’t arbitrary. Acorns from red oaks don’t germinate until spring, while acorns from white oaks germinate immediately when they drop in the fall, sending down a taproot and, as a result, using up the nutrients in the acorn. So the squirrel, somehow knowing the difference, eats the fall-germinating white oak acorns immediately while burying the spring-germinating red oaks to save them for later. What if though, in a particular year, there is an abundance of white oak acorns but a scarce supply of the red oak variety? Well, the squirrel has a strategy for that, too. To prevent the white oak acorn from germinating, they destroy the embryo before burying the acorn, explains Smallwood.
Another thing Smallwood learned while watching squirrels is that squirrels know when you’re watching. As every heist-caper film you’ve ever seen makes clear, there’s no honor among thieves, and one squirrel is perfectly happy to dig up another squirrel’s carefully buried acorn. To foil such predation, the squirrels have developed a crafty paranoia. “They practice deceptive caching,” says Smallwood, explaining that if one squirrel thinks that another might be watching, it will—with all the deliberation of a Method actor—go through an elaborate display of stereotypical burying behavior, then run off with the acorn still in its mouth, foiling the watcher’s thieving ambitions.
And then there’s your bird feeder. To a squirrel, born to an acrobatic life in the vertical world of trees, it’s all in a day’s work. “They are selected,” says Smallwood, “to solve three-dimensional puzzles.” When the producers of the UK documentary Daylight Robbery 2 (see the video tab for a YouTube clip) constructed an elaborate “super assault course” with leaps, spinning tubes and even a ride in a rocket car, it took the local gray squirrels only a month to master the setup and get to the food at the end.
The challenge highlighted the remarkable agility of these backyard aerialists. They can jump up to seven feet from a standing position, scramble along the narrowest wire, and swivel their ankles around backwards to hang by their toenails from a tree trunk—handy when hurling imprecations at passing dogs.
Squirrels have their darker side, too. Smallwood has seen them take road kill (including their own dead brethren), and steal eggs and baby birds from the nest. But it’s their own vulnerable position on the food chain that helps explain one of their more mysterious behaviors—why they seem to suffer a helpless compulsion to throw themselves under oncoming automobiles. As it turns out, “they’re not so much running out in front of your car as dodging,” explains Smallwood. When escaping pursuit by a hawk or other predator, a squirrel’s preferred strategy, he says, is “to wait until the last moment and then dodge out of the way.” Alas, this tactic proves counterproductive when the looming threat has an engine and four wheels.
And yet a squirrel is a tough nut. Once I was standing on the sidewalk when one plummeted from the branches far above to hit the pavement with an audible “crack!” After a brief pause it rose, shook its head, then shot off up the nearest tree. No doubt it had my bird feeder to get back to.