September 15, 2018
The adage about not judging a book by its cover is spot-on for squirrels. These critters may look cute — the stuff of cartoons and greeting cards — but they can be infuriating foes.
Tree squirrels are ubiquitous. The familiar Western gray squirrel, sporting its iconic bushy white-tinged tail, enjoys oak and pine forests — and your garden. The Eastern gray squirrel, first introduced into Golden Gate Park, has the dubious distinction of being on the list of 100 world’s worst invaders by the Global Invasive Species Database. Reddish-brown Eastern fox squirrels are also displaced East Coasters — and highly mischievous.
Active all year, these acrobats are excellent entertainers, amazing us mortals as they zip across powerlines and zoom through tree canopies. During breeding season, tree squirrels chatter adorably and scamper up tree trunks and telephone poles, the males loudly pursuing females. They live in tree cavities and build cushy nests called dreys. When frightened, they chirp-bark, stamp feet and flick tails.
Unfortunately, tree squirrels have some less-endearing habits. They decimate fruit and nut trees, tear up lawns, gnaw phone lines, chomp into buildings, strip bark, and carry fleas, mites, and ringworm. Don’t get me wrong: they’re not intentionally evil. It’s just that when we grow apricots, tomatoes, strawberries and other tasty goodies, it’s difficult to persuade squirrels to dine elsewhere. And when we live in homes with aging vents and wooden siding, those man-made barriers may be no match for squirrels’ natural instinct — and sharp teeth.
If you’ve fought and lost the squirrel battle, take heart: they do have two important eco-benefits. Like furry Johnny Appleseeds, they bury nuts here, there and everywhere, a habit called scatterboarding, then unearth their buried snacks by smell in winter. But some seeds are forgotten and sprout, thus helping with forest renewal. Squirrels are also keystone species, meaning other species such as owls, hawks and foxes rely on them.
If that doesn’t allay squirrel frustrations you may be harboring, then please consider anti-squirrel techniques. Close entrances to your home or attic with sheet metal or ¼-inch wire mesh. Protect trees with bird netting. Enclose veggie crops with one-inch chicken wire. Do not leave out pet food or hang bird feeders that aren’t squirrel-proof.
If all else fails, be happy you don’t have ground squirrels, the most serious native rodent pest in California that confounds farmers and inflicts up to $50 million of damage every year. They eat crops, chew irrigation lines, carry fleas and diseases, weaken hillsides, re-route waterways, harm farm equipment, undermine roadways and buildings, deplete livestock forage and sprain ankles.
Ground squirrels dig burrows for shelter and safety, with generations inhabiting the same burrow for years. Most protect and stay 150 yards from their burrows, even killing snakes when necessary. Lucky for them, they’re immune to rattlesnake venom. Part-time architects and full-time excavators, they add on to burrows every year — and live around six years. Each remodeling phase results in more openings, with each squirrel boasting his or her own entrance. One notable squirrel village measured 741 feet long, had 33 openings and was 28 feet deep.
Good luck digging that out with a shovel. Even if you went full Bill Murray gopher-crazy and took a backhoe to it, you wouldn’t eradicate this squirrel condominium complex, because the evicted tenants leave pheromones that attract new squirrels.
Ground squirrels hibernate in winter, reproduce in spring, then line up for the all-you-can-eat buffet in summer. Make no mistake: these guys are hungry. Twenty squirrels consume as much as a sheep in one day. They eat greens, grains, nuts, seeds, fruits, tubers, acorns, roots, mushrooms, birds’ eggs, and insects — stuffing excess into cheek pouches for later. Some are mini Hannibal Lecters, scavenging road kill to cannibalize their own or other furry victims.
Squirrel behavior isn’t always appealing to humans, so aim to appreciate their darling faces and amusing antics instead.