Squirrels: Why many aren't nuts about them
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Eastern grey squirrel. Photo: Wikimedia Commons
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.
Cute, right?
Tree squirrels: cute but destructive
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.
Ground squirrels: the most serious native rodent pest in California
California ground squirrel pair. Photo: Wikimedia CommonsGround 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 have been confounding farmers for generations. Photo by Jack Kelly Clark, UCANR
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.
Managing tree and ground squirrels
If squirrels are creating havoc in your garden, heed the advice of the experts and the University of California. And please avoid baits, which are not appropriate control methods for Marin County gardens and can harm other wildlife. See below.
By Marie Narlock