The Nature of Cedar Mill

Your Backyard Squirrels

By Kyle Spinks, THPRD Natural Resources Technician

Most of us have seen the ‘high-wire’ act of a squirrel running across utility lines over city streets…and not without a little amazement at such a feat! These furry little animals are commonly seen in our backyards, often eating the seeds out of the bird feeders we’ve set up. But did you know we have five species of squirrel in the Metro area?

Western Gray Squirrel

Western Gray Squirrel – Sciurus griseus: The largest of our native species, this beautiful squirrel is all gray on the back and bushy tail. It has a whitish belly and the body averages 11” long. It is commonly found in hardwood forests dominated by Oregon white oaks. It dines on acorns, our native hazelnuts, and is very fond of underground fungi. Unfortunately, this beautiful species is losing ground to habitat loss and competition from introduced squirrels (see Eastern Gray and Eastern Fox Squirrels, below) and a population in southern Washington State has been proposed for listing under the Endangered Species Act.

Eastern Gray Squirrel – Sciurus carolinensis: This introduced squirrel grows to about 9” long on average (not counting the tail). The coat is mostly gray with brown highlights on the side and the belly is white. The face, ears, and feet are typically brownish and the bushy tail has a brownish cast to it with white-tipped hairs. This is a very common squirrel that can be found in a variety of habitats, but prefers those with lots of bigleaf and vine maples where the seeds, buds, and twigs of these trees make up a large part of their diet. They may also dine on fungi, berries, and occasionally bird eggs. They are also know to peel the bark of woody plants to eat the cambium layer inside, which may kill the branch.

Eastern Fox Squirrel

Eastern Fox Squirrel – Sciurus niger: This squirrel is mostly brownish-red with an orange belly, the ears are shorter than the Western or Eastern Gray Squirrels, and the body averages 10” long. This introduced species is one of the most common species found in the Metro area parks and is often seen where nut orchards or native hazelnuts are nearby.

Douglas’ Squirrel – Tamiasciurus douglasii: Named after the famous naturalist David Douglas, this is the squirrel you’ll likely hear chattering in the Douglas-fir forests in our region, often as a rapid-fire descending call echoing through the trees. Its body averages about 8 inches and its tail is less bushy than the previous three squirrels. It has a dark gray coat with brownish undertones and an orange belly. It eats primarily conifer seeds and shoots and the telltale signs of a Douglas squirrel are the remnants of a cone that is in hundreds of pieces on a stump or log. It will also eat fungi, leaves, and flowers, and will peel bark to eat the cambium layer of woody plants.

Northern Flying Squirrel – Glaucomys sabrinus: This is the smallest of our forest squirrels, reaching only about 6” in total body length. It is also the squirrel that is least likely to be seen since it is mostly nocturnal, and its very large eyes are typical of nighttime animals. But if you do see one watch it carefully and you may see it leap and glide from tree to tree! This is the only squirrel that has large flaps of skin between the front and rear legs that spread out when it leaps, allowing it to glide through the air (thus, it doesn’t truly fly…but we won’t quibble over details of this unique form of transportation). The coat is gray with hints of brown and the belly is buffy-brown to the exact edge of the skin flaps between the legs. The brownish tail appears flattened due to the black-tipped hairs that spread laterally. The Northern Flying Squirrel in northwestern Oregon feeds almost exclusively on fungi, but in eastern Oregon supplements its diet with lichens.