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Western Gray Squirrel EC 1572 May 2005 S. Headley and S. Sells Do you want to print a copy? We recommend downloading the print version (343 KB). First download the free Adobe Reader, if you don't already have it. Contents Species description Where they live and why Creating habitat Fun facts Have you ever watched a squirrel? Watching squirrels is fun. They look like a circus act as they jump from tree to tree. They run along tree branches, leaping from branch to branch—it is unbelievable that they can move so fast and not fall! Sometimes you can hear them barking even when you cannot see them. You may find chewed nutshells and pinecones scattered beneath large trees. Up in the trees, you may see squirrels’ large, leafy nests. The best time to watch squirrels is 1 to 2 hours after sunrise. As the day warms up, squirrels spend more time resting. They may sprawl on their belly on tree limbs with their legs and tail dangling. Or, they might sit on a limb with their tail curled over their back. The Western gray squirrel is listed in Oregon as a sensitive species, which means it is declining in population. In Washington, the species is listed as threatened, which means there is concern of possible extinction. Competition with other species and loss of oak woodlands and older trees may contribute to the species’ decline. The Eastern gray squirrel, which was introduced from the eastern United States, looks a lot like our Western gray squirrel. Eastern gray squirrels compete for much of the same habitat and food as the Western gray squirrel and are more aggressive. They also are fond of bird seed and often raid feeders. They can be troublesome for homeowners by getting into attics and digging up flower beds. Species description Animals are grouped according to similar characteristics and relationships, and squirrels are part of a very large group, or order, called Rodentia, the gnawing mammals we call rodents. Within this group, squirrels are in the Sciuridae family, a large subgroup that also includes chipmunks, flying squirrels, and marmots. The Western gray squirrel is the largest tree squirrel in Oregon. Western gray squirrels look silvery gray, except for their belly, which is white. White tips on gray hairs give them a silvery appearance. They have a bushy, silvery gray tail with black hairs. Adults weigh between 18 to 33 ounces. They can be as long as 2 feet, including their tail. They have strong, curved claws and strong legs for tree climbing and leaping. Look for squirrel tracks the next time you are outside. Their front feet leave 1-inch-long round tracks with four toe prints. The back feet leave 2.25-inch-long tracks with five toe prints. When a squirrel runs or hops, its trail has the hind prints in front of the fore prints. Tracks are especially fun to look for in the snow, when squirrels may leave trails from tree to tree. Western gray squirrels are diurnal, which means they are active in the daytime and sleep at night. When squirrels wake up at sunrise, they first groom themselves. They are most active during the first 2 to 3 hours of the day. Squirrels spend a lot of time looking for, storing, and eating food. They often store their food to survive during seasons when less food is available. About 3 hours before sunset, squirrels usually go to their nests for the night. In the winter, they like to sleep in tree cavities, which are holes (often made by woodpeckers) in tree trunks. They also build nests called dreys high in trees. A drey is a flat nest made of large sticks on the outside and lined with soft leaves and shredded bark. Dreys often are used for sleeping and raising young. Female squirrels give birth after being pregnant for at least 6 weeks. A litter can range from one to five young, though two or three seem common. Females give birth to one litter between February and June. The young may be born in dreys, or they may be born in tree cavity nests and moved to dreys when they are older. They are born with their eyes closed and without hair. You can look for babies outside of their nests beginning in mid- to late spring. Squirrels are eaten by bobcats, weasels, coyotes, hawks, owls, snakes, and other predators. Humans hunt squirrels, and many are hit by cars. Where they live and why Western gray squirrels live in many parts of California, Oregon, and Washington. In Oregon and Washington, they live mainly on the west side of the Cascade Mountains, but some also live on the east side. They generally do not live on the coast. In California, they live nearly everywhere except for the Central Valley, the coast, and most of the deserts of southern California. Western gray squirrels are arboreal, which means they live in trees. They also spend time on the ground traveling between trees and looking for food. They prefer wooded areas with lots of oak trees. They also are found near streams and in forests where there are maples, tanoak, madrone, Douglas-fir, white fir, and pines. They also live in urban parks and orchards near forested areas. Squirrels eat a variety of foods. They prefer fungi, acorns, and seeds from trees such as Douglas-fir, true firs, spruce, and pines. On a quiet day, you may hear a nibbling noise coming from high in a tree. If you look closely, you might find a squirrel holding a pine cone in his hands like a corn cob and chewing on it. In the summer, squirrels also eat green vegetation, berries, and insects. Squirrels are like miniature tree farmers. They help new trees grow by storing nuts and seeds in the ground, hoping to eat them later. If they forget where they hid them, the seeds can sprout into new trees. Squirrels also help plants by eating aphids, a type of insect that can attack Oregon ash trees and cause a disease called leaf roll. Squirrels can damage trees by chewing the bark when food is scarce. Creating habitat Western gray squirrels need you to maintain and create habitat for them! If you have oak trees in your habitat area, that’s a good start. If not, you can plant oaks or other trees that produce seeds or nuts, such as maple, walnut, hazelnut, spruce, sugar pine, ponderosa pine, and lodgepole pine. Knowing your area’s soil type and weather will help you decide which species to plant. You can provide shelter for Western gray squirrels by leaving large trees and dead or dying trees if they do not pose a safety hazard. If woodpeckers make cavities in these trees, squirrels can nest in them after the woodpeckers leave. If you wish, you can attract squirrels to feeders with peanuts, walnuts, corn, sunflower seeds, and suet. Squirrels like to eat corn. Simple feeders can be made to hold an ear of corn. There are many other types of squirrel feeders, which you can buy at bird and nature stores or online at sites such as http://www.wildwoodfarms.com, which has over a dozen fun and interesting designs. Please note, however, that feeding squirrels can attract the non-native Eastern gray squirrel rather than the more shy Western gray squirrel. Too many squirrels in one area can drive away birds and other desirable wildlife. Fun facts Tree squirrels don’t hibernate. They store nuts to last through the winter. Squirrels can use their tail as a parachute and to land on if they fall out of a tree. There are more than 270 species of squirrels. They live in a variety of habitats around the world. Squirrels look different than chipmunks; they have no stripes on their faces. Some squirrels are arboreal (live in trees), while others are fossorial (live underground in burrows). Prepared by Sandra K. Headley and Sarah Sells, students in Fisheries and Wildlife, Oregon State University. Published May 2005

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