Tree squirrels of the Pacific Northwest

Which of these descriptions best describes the squirrels who pass through your garden?

A lively, adorable, cavorting, wide-eyed, bush-tailed acrobat and is a joy to watch. Or the destroyer of flower beds and home irrigation lines, raider of bird feeders, disease-carrying rodent full of fleas and ticks.

Washington has four native species of tree squirrels: the Douglas squirrel, the red squirrel, the Western Gray squirrel and the northern flying squirrel. In addition to our native squirrels, the eastern gray squirrel and eastern fox squirrel were introduced in Washington in the early 1900s. They are the most common tree squirrels in urban areas.

Squirrels eat acorns, seeds, tree buds and berries as well as plant material and twigs. Occasionally they will eat parts of a bird’s nest – the eggs or baby chicks. Insects and fungi are also a part of their diet. They store their food in hollow stumps, abandoned burrows and any hidey-hole they can find - including exhaust pipes, under flowerpots and in unused cars.

Hollow cavities are also used for nesting. Leaves, twigs, shredded bark, moss, insulation and other soft materials are used to structure their nests. They also build cone shaped nests in trees, bird nesting boxes or even attics. In cold weather, red squirrels may nest underground, often near where they have stored their food. Urban squirrels generally nest in buildings or other structures.

Mating occurs in early winter to late spring, with one litter of two to four babies produced in March through June. Some species may have a second litter in August or September. Squirrels can live for three to five years, but most die within their first year.

Squirrels are most active from dawn to dusk. They do not hibernate in winter but remain in their nests if the weather is stormy or cold. Tree squirrels can be destructive to bird feeders and bulb plantings, among other things. Should a squirrel decide to take up residence in your attic or down your chimney, you will not be pleased. To limit this, look around your buildings and eliminate access through dryer and roof vents, rotten siding or boards. Keep tree and shrub branches pruned away from buildings and roofs to eliminate access to these areas. Barriers around fruit trees, bulbs and tree bark can be used to deter these determined creatures.

To prevent potential conflicts, you should never feed squirrels. Use squirrel-resistant bird feeders and check bird nesting boxes for squirrel nesting sites. If a squirrel gets adapted to hand-feeding (as cute as it is), it may lose the fear of humans and become aggressive. If a person is bitten or scratched by a tree squirrel, immediately scrub the wound with soap and water and flush liberally with tap water.

How would you describe the squirrels in your yard? Cute and amusing entertainers or destructive, vermin-infested rodents? Perhaps a little bit of both? For more information about squirrels or other pertinent gardening information, go to our Ask a Master Gardener Blog at skagitmg.org/pnw-tree-squirrels.

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