White oaks, for example, made what looks like a bid to game the terms of the coevolutionary contract by producing acorns that germinate rapidly, sprouting soon after they are buried. To thwart this strategy and still reap the energy in the nutmeat, squirrels eat these nondormant seeds rather than burying them. When they do decide to bury a nondormant acorn, they first gnaw out the embryo, transforming the seed into an inert mass of calories that cannot sprout.
Steele and other scientists investigating half-eaten acorns have found that an acorn has more fats, which squirrels like, in its top half, and in its bottom half, around the embryo, there are more tannins, which squirrels dislike. Tannins—the same chemicals that make wines “dry”—are poisonous in high concentrations. They are a mainstay of plant chemical warfare, used by everything from apples to persimmons. That feeling of all the moisture being sucked out of your mouth when you bite into an acorn or an unripe apple comes from the tannins you’ve just released, which act as molecular vacuum cleaners, hoovering up all the proteins that make your saliva feel slippery. Unlike squirrels, humans can’t eat acorns without processing the tannins.
The researchers thought they’d found the answer: The oak trees are giving the squirrels half of each acorn, yet protecting the important bits. And, it seemed, guiding the squirrels to the more delicious half of the acorn with its shape. When a researcher whittled acorns so the top looked like the bottom and vice versa, the squirrels ate the wrong end: the one containing more tannins, less fats, and most importantly, the embryo. Squirrels use the shape of an acorn to find the tastier end, just as we use the shape of an apple to bite into the flesh rather than the core. If a team of devious scientists reshaped our apples so the core ran widthwise, we might find ourselves inadvertently eating it.
When squirrels are hungry, they always eat the whole acorn. But when there is an abundance of them, they will just eat the best part and discard the rest. This may explain the evolutionary logic behind a mast year: By producing gigantic pulses of nuts, oak trees ensure that some of their acorns will make it past the predators. The same logic drives trees, even in normal years, to produce all their nuts or fruits within a small window of time. The tree evolved toward boom and bust. The squirrel is a shock absorber. By working to bamboozle each other, they work together.
SQUIRRELS AND PEOPLE
Of course, squirrels eat more than acorns, and their options are especially diverse when they live among humans. Humans frequently put out buffets of seeds from which squirrels can eat their fill. The humans, however, usually intend these seeds for wild birds and view the squirrels as unwanted guests. You probably know some of these humans.
There’s a whole genre of Internet videos and forums dedicated to the contest between humans and squirrels for control over bird feeders. I have a book on the subject: Outwitting Squirrels: 101 Cunning Stratagems to Reduce Dramatically the Egregious Misappropriation of Seed from Your Birdfeeder by Squirrels, by Bill Adler Jr. The fact that humans must summon this much collective brainpower and earnest scheming to match wits with a one-pound rodent says something not so complimentary about us. At the end of his book, Adler urges his readers not to give up and admit defeat:
I have high hopes for civilization. We have survived world wars, the cold war, devastating plagues. We have gone to the moon, and sent probes past the outermost edge of our solar system. We have eliminated major diseases, and we have invented Wheel of Fortune.
But only if we keep up our struggle to outwit squirrels can humankind expect to progress towards the next level of development, whatever that may be.
Late one night, lost deep in the Internet of squirrels, I stumbled across a series of videos by Steve Barley that offered an admirable alternative to the no-holds-barred warfare I’d grown used to seeing, and I was moved to write to him.
Barley, who lives in suburban Hertfordshire, England, entered into his relationship with squirrels in the traditional way: They destroyed his bird feeders, and he got annoyed and started looking for ways to stop them.
His local squirrels severed the rope supporting one feeder, sending it crashing to the ground. Squirrel incisors also made quick work of his plastic feeders. Next, Barley bought steel feeders covered in wire mesh. Of course these didn’t deter them either. But as Barley watched the squirrels dismantling the defenses, instead of growing angry, he began to feel something resembling admiration.
“It was only when I watched them figure out how to hang upside down on the wire mesh “squirrel-proof” ones and then widen a hole low down with their teeth and claws to get the nuts out like in a gumball machine that I began to respect their ingenuity and acrobatic skills,” he told me.
“They were fascinating to watch, especially the way they can reverse their rear claws to hang on with ease, leaving their front paws to do their stuff.”
Squirrels have hinged ankles that rotate 180 degrees. For comparison, imagine a ballet dancer going up on pointe; that’s not quite ninety degrees. This flexibility allows squirrels to drape themselves over the shields and baffles employed by some bird feeders. Squirrels also have the right sort of brain for this sort of thing. They are problem solvers, Delgado had told me, motivated and persistent. And though they lack opposable thumbs, they have good motor skills and dexterous fingers.
As Barley and his son were watching the squirrels empty the feeders, he hit upon the idea of hanging one off a clothesline, just to see how they would manage it. This was not much of a challenge: The squirrels made what had looked like an impossible leap from a bird platform. At this point, Barley’s annoyance ceded to curiosity: How much could these squirrels do?
“We experimented with a piece of trellis,” Barley said, “and they jumped onto that to reach the feeder hanging further down the line.” He and his son were playing with the squirrels now rather than against them, and kept adding bits and pieces to the collection of obstacles: an old ironing board, a plunger, a bicycle mudguard, a lampshade, and on and on.
They filmed squirrels making short work of this obstacle course, and, as is the way with these things, it ended up on You-Tube, where it became a minor sensation.
As amusing as Barley’s contraptions are, they don’t truly test the outer limits of what squirrels are capable of doing. The closest we have ever come to accomplishing that was in 1999, when the BBC built an obstacle course for a series about squirrels called Daylight Robbery (Barley hadn’t seen it when he started building his own in 2010).
To beat this course, squirrels had to climb up through a vertical pipe, leap onto a blade of a spinning windmill, cling to it, and then sail off on the right trajectory to land on a platform. Then they had to go paw over paw upside down along a suspended chain that passed through a series of spinning disks, negotiate a revolving door, run through a slack canvas tube, and keep their balance while crossing a pole covered with slick spinning rollers. From there, it was a six-foot jump to another tunnel, through which they had to ride a sliding vehicle made to look like a rocket ship by pushing it along with their paws. Finally, there was an eight-foot jump to the food.
This challenge took the squirrels a little over a month to figure out. They mastered the obstacles with varying levels of grace—one female learned to complete the course without hesitation or error each time she tried, earning her the starring role in the production.
Despite their skills, squirrels are not known for their cunning, or their athleticism. Squirrels are known for their teeth: They have no canines, so they have their distinctive incisors sticking way out in front and then a honking gap between those and their molars. The incisors have a chiseled edge that’s sharpened by use. These grow continuously throughout life (as is the case with many rodents), and squirrels must wear them down.
Squirrels are also known for their tails. The tail becomes an effective blanket when it is cold, an umbrella when it is wet, and a cooling system when it is hot. In hot weather a squirrel can dilate arteries at the base of the tail to allow blood to rush down its length, whe
re the heat from its core may dissipate.
The scientific name for the squirrel genus is Sciurus, which translates roughly to “shade-tail.” The squirrels in North American cities are eastern grays (Sciurus carolinensis, “Carolina shade-tail”) and eastern fox squirrels (S. niger, “swarthy shadetail”). The eastern grays also come in black—as do many of those around Washington, DC—and there are a few populations that are entirely white.
Eastern grays were the first to populate cities, but fox squirrels, which are larger and have bigger brains, are pushing them out in some places, like my town. Fox squirrels have darker coats, with a ruddy orange fringe along the bottom by their paws.
Outside cities, there are several others: the western gray in the Sierra Nevada, the Arizona gray and Abert’s squirrels in the Southwest, and the Eurasian red across the Atlantic. In England the red squirrels have retreated to the northern conifer forests because they are unable to cope with the diseases introduced by eastern grays—one native American species taking retribution for smallpox and cholera. In North America our conifer tree squirrels are larder hoarders that build and defend towers of cones. In the east there is the red squirrel, Tamiasciurus hudsonicus, the hoarding shade-tail of the Hudson, and in the Pacific Northwest the Douglas squirrel, T. douglasii. But if you see a tree squirrel in a city, it’s almost certainly a fox squirrel or an eastern gray.
Reluctant Urbanites
Before 1840, cities were pretty much squirrelfree. The historian Etienne Benson has shown that it took painstaking effort to urbanize squirrels. City beautifiers released squirrels first in Philadelphia, then in Boston, and in New Haven, Connecticut. They provided the animals with food and nesting boxes. Children were encouraged to bring them nuts and cakes.
These days we generally discourage kids from feeding wild animals. We want our city wildlife to live parallel to us, never quite touching us. But back then, people wanted to civilize wildlife. Benson relates that George Perkins Marsh, often called the first American environmentalist, applauded the city squirrels, saying their tameness “was a foretaste of the rewards to be expected when man moderated his destructive behavior toward nature.” In other words, once Americans stopped conquering the land, we could settle down to live in harmony with the conquered. That harmony would look a lot like a city park full of gracious trees and squirrels that would eat out of your hand.
And eat they did: A report in 1865 declared that the squirrels in New Haven Green had “become so obese from good living that they are continually missing their hold and falling from the tree tops.” But despite all this effort to feed and house the rodents, the initial squirrel urbanization projects failed. The squirrels died; the environment just couldn’t support them. Presumably, after the initial enthusiasm for feeding squirrels wore off, obesity gave way to starvation. To move in and take over cities, squirrels needed an ally to reshape their landscapes. They found that ally in Frederick Law Olmsted.
Olmsted introduced the idea that cities should contain large tracts of idealized wilderness (his most famous design was New York’s Central Park). It was ideal for reading poetry in the shade or wandering with a friend, but mostly, it was ideal for being a squirrel.
In 1883, six years after sixty-eight squirrels were released in Central Park, it had an estimated population of 1,500. Olmsted is the acknowledged father of American landscape architecture, but it’s not as well recognized that he also is the father of city squirrels. City dwellers unwittingly contributed to the effort by lining the streets with trees and installing elevated squirrel transportation infrastructure in the form of telephone and electrical lines.
To Love or to Kill
In the late 1800s, not everyone approved of Marsh’s vision of wilderness tamed. There were also those who said it was ludicrous to think that nature could ever be conquered and wanted to keep fighting it. This debate was personified on one side by Ernest Thompson Seton, who in 1910 helped start the Boy Scouts of America and wanted to befriend nature. On the other side was Theodore Roosevelt, who wanted to hunt down and kill nature. Both Roosevelt and Seton were fascinated with manliness, and they both believed that communion with wild animals was a crucial part of the mystical process that transformed boys into men of character. But their agreement ended there.
Seton thought squirrels would teach boys to be nurturing and empathetic. “Some day,” Seton wrote, “while a boy is feeding a squirrel, a dog may dash at it with evil design and the child will certainly and naturally try to save the squirrel that he was feeding, and thus cast in his lot with the squirrels against the dogs.”
This would plant a seed of empathy that would blossom into righteousness and chivalry. Seton wrote, “You can rely on work being done by these missionary squirrels whose influence will not end with the boundaries of the city park, but will continue to go as far as the boys go.”
Roosevelt thought squirrels, and all wild animals, were there to teach boys to learn courage. In his view, you’d start by killing spiders and beetles, move on to birds and squirrels, work your way up to bears, and before you know it you’d be a general like him. Ultimately, you’d need a war to truly become a man, and Roosevelt lamented that too much peace was emasculating the United States. Instead of teaching boys to protect squirrels so that they might later protect people, Roosevelt wanted boys to kill squirrels so they might later kill people.
Roosevelt attacked Seton for being a “nature faker,” and the slur stuck because it was true, at least in part. Seton sought to teach morality with animals, but to do this he took outrageous liberties in giving animals human qualities, populating his writing with heroic rabbits, crows that fly in military formation, and rams driven by dandyish pride.
But Roosevelt was just as much a faker. He constructed his macho persona from the ground up. When he first entered public life at the age of twenty-three as a New York state assemblyman, he was a rich kid with soft hands, a squeaky voice, and clothes that were a little too fashionable for his own good. The newspapers gave him nicknames: “Jane-Dandy,” “our own Oscar Wilde,” and “Punkin-Lily.” He went west to shake this reputation. Viewed from this angle, Roosevelt’s entire life looks like one gigantic exercise in overcompensation.
This argument between Roosevelt and Seton over nature and manhood had staying power. To this day, when people argue about saving endangered species or managing wildfires or responding to climate change, you can detect the ghosts of Roosevelt and Seton in the background.
I’ve spent a lot of time considering what lessons I want to pass on to my own kids. I grew up in the Seton mode: I understood that my moral development depended on protecting squirrels rather than shooting them. And yet, I wouldn’t want to pass on Seton’s ideology to Josephine, because it has so little grounding in reality. I’d also like to keep her away from Rooseveltian displays of masculine violence. Rather than conquering nature or giving it fake human morality, I’d want her to simply approach nature with open eyes and curiosity.
The Squirrel That Owns My House
One of the benefits of writing about squirrels, as opposed to, say, wolves, is that—thanks to those nineteenth-century civic boosters—you can see them without any effort. There’s one squirrel that likes to eat the rose hips that hang over our wooden fence. It’s a fox squirrel, orange and white underneath and gray on his back. One morning he and I found ourselves face-to-face as I was taking my coffee grounds out to the compost pile. The squirrel was on top of the fence, at eye level about three feet away, gripping a rose hip in his mouth. There was what seemed like an insane intensity in his beady, close-set eyes. He regarded me with a cheeky lack of respect, then scrabbled forward and down onto the vertical face of the fence, all four legs spread. In this gravity-defying position, he traversed to the far end of my backyard.
I can’t help but see human emotions in squirrels. But I try not to go as far as Seton did—I refrain from making up motives and morals, and I strive to watch closely enough that my ideas might be shattered by something a squirr
el does.
I don’t feel bad about anthropomorphizing my furry neighbor. That’s just how people work: We project our own expectations and ways of understanding the world onto the creatures around us, be they squirrels or family members. A few days earlier Josephine—at this point three years old, and a genius—had seen the same squirrel running along the same fence.
“Papa,” she said, pointing. “A cat!”
I do the same thing; I just don’t have someone around to correct me. We see what we expect to, what we have a name for, what pops immediately into our heads. But confirmation of the expected is boring, and false. Life only becomes interesting when you watch it closely enough to see something surprising, and with that surprise come a little closer to the real thing. That, I suppose, is the point of this book: to allow people to see past their expectations. When actual seeing pierces the skin of habituation, if only for a moment, it permits a bit of wonder to bleed through. Wonder is the animating ether that allows some lucky few to perceive not just the prosaic, but the most profound laws of the universe at work in the prosaic. I think that’s what the poet Philip Appleman was getting at in the prologue of Darwin’s Bestiary when he wrote:
The habit stays with us, albeit it’s puerile:
when Darwin saw squirrels, he saw more than Squirrel.
SQUIRRELS ON SQUIRRELS
Unseen City Page 7