Many of you may have noticed, while walking through our Douglas fir forests this spring, occasional spots where the trails are massively littered with small, green fir cone scales. It’s a beautiful and impressive sign of California grey squirrel feeding, and I have seen it in years past, but this year the scales are more abundant—a sign, perhaps, that local squirrels are doing particularly well.
I began stopping for a while near these litter piles. Soon, especially just after dawn and before dusk, the squirrel families would resume their activities around me, scolding, calling, chasing and feeding in a burst of motion.
One thing that caught my attention this year was the conspicuous absence of cones or their cores on the ground, meaning the squirrels were not cutting the cones off and dropping them—they were de-scaling them up in the branches and eating the newly forming nuts up there. Whew! What an appetite for those sappy, bitter fruits!
One day, while inspecting a particularly prolific scattering, I noticed a heap of small strips of thin bark. Looking closer, I saw that the inner surface of every strip was covered with faint diagonal stripes, all double grooves about 1/8” wide— the squirrels’ incisor marks. They were stripping bark and scraping off the sugar-rich cambium layer.
Unable to resist, I climbed the tree. Sure enough, about 40 feet up, I found numerous large, bare patches on the trunk and bare strips on surrounding branches where the bark had been chewed away.
This is springtime behavior. The kids are born and learning the ways of the trees, safe from ground predators. The new fir cones are starting to ripen, certain trees producing stronger crops and sweeter sap. The growth is a welcome addition to fall supplies cached on the ground. Sometimes the squirrels chew circular patches on horizontal branches, creating sap wells. By leaving these wells to fill and evaporate, they can double the concentration of the sugars and other nutrients in the sap.
Grey squirrels have intense social interactions that give rise to a constant flurry of territorial marking and defense, illustrating a principle that is common throughout nature: the multiple layers of meaning in everyday tasks. Grey squirrels create territorial chew marks in certain areas, adding to them regularly and marking them with scent from the glands on their cheeks. Some of these chews are maintained for decades in the same large trees, growing to immense sizes.
In spring, males form strict hierarchies, fighting to be in position when a female comes into her brief estrus, perhaps for only eight hours in the whole year. A female can lead an entourage of males on wild chases through trees. This social positioning and territorial boundary-keeping, along with relentless feeding to maintain their high metabolisms, accounts for their noisy and obvious
activity.
Grey squirrels’ spectacular tail, for which they are named (their genus, Sciurus, means “shade-tail”), also serves several purposes: a blanket when it is cold, a parachute in case of a fall, a balancer on leaps and dashes through branches and an effective signal device.
We are probably all familiar with their incessant “kuk, kuk, kucking” calls, which they use in coordination with tail flicking to challenge competitors or warn neighbors of potential danger. Though they have found relative safety in the trees from ground predators, grey squirrels are also vulnerable to owls and hawks. They are on constant alert, quick to flag any threat and disappear into secondary nests and thickets when an alert becomes an alarm.
Summer brings a shift in eating habits, indicated by the appearance of the cores of fir cones in the litter of scales below feeding trees. The cones are maturing and the squirrels are beginning to sever the whole cone and strip it by rotating it in their front paws like corncobs, dropping the core to the ground. As summer progresses, they begin cutting off cone-covered branch tips, then dashing down and out from the bases of trees to strip the cones on the ground and start their seasonal food caching.
This is perhaps where their erratic movements have given birth to our term for someone with a flakey and unpredictable nature—someone who acts a little “squirrelly.” But in the billion-year-old wisdom of evolution, this comical and endearing behavior has multiple advantages. The herky-jerky bounding motion is designed to be unpredictable to a potential predator; without it, squirrels would be vulnerable during months when they spend more than half their time on the ground, sometimes far from the safety of trees.
Their maddening hop-and-stop, this-way-and-that way motion also serves to confuse thieves ready to steal the newly cached seeds, hidden just under the top layer of forest debris. A single squirrel can store thousands of seeds and nuts—and is able to recover 90 percent of them during the winter, aided by a remarkable spatial memory (like that of Clark’s nutcrackers) and a precise sense of smell. They use a “scatter-hoarding” strategy, increasing the odds of sufficient winter food supplies by spreading it out widely.
In fact, quite a bit of give and take goes on with these scattered caches; you could call it thievery or, more altruistically, neighborly support. Often, when you sit still long enough, you can see the squirrels making phony caches—false digs a short distance from the actual cache—to throw off spies. And, like old misers, they continually reshuffle their caches, counting and re-hiding their treasure.
This iconic friend, obvious, relentless and yet also mysterious, was hunted nearly to extinction around 1900, when a century of unregulated hunting and killing mania had run much of wildlife in America to the brink of extinction. Luckily, a conservation movement was born, and is still making headway against the mindless and ignorant attitudes of a human culture dangerously out of touch with the earth we inhabit.
The hope and humor a squirrel provides can be an inspiration to continue our push to rebuild a true Garden of Eden here on earth.
Richard Vacha lives in Point Reyes Station, where he makes a living as a craftsman and has studied tracking and awareness for 30 years. He feels he is beginning to get a feel for it by now, and is building the Point Reyes Tracking School, to offer classes and other programs, at PRTS.me.