Tamiasciurus hudsonicus
red squirrel

Red squirrels are native to the Nearctic region and have one of the widest distributions of all North American squirrels. They are found from Alaska continuously across Canada to the northeast United States and south through the Appalachian states. They also occur throughout the Rocky Mountains. (Ruff and Wilson, 1999)

Red squirrels are found in a variety of forested habitats, including coniferous, deciduous, and mixed forests. They can be found in suburban settings where there are large stands of mature trees. (Ruff and Wilson, 1999)

Red squirrels have a total body length of from 280 to 350 mm, with the tail making up from 95 to 150 mm of that. Fur color is highly variable. Red squirrels in different part of their range can look quite different. Color changes between summer and winter as well. The fur on their back is usually brownish or olive-red in color. During the summer, a black stripe runs along their side, between the fur color of their back and their belly. The belly is white or cream color. The tail is often edged with white. There are white bands encircling their large, black eyes. The tail is not as thick or bushy as other North American tree squirrels. They are well adapted for climbing and running through the trees with compact, muscled bodies, strong claws, and powerful hind limbs. (Ruff and Wilson, 1999)

In warmer climates there are two breeding seasons, in the late winter and mid-summer. In colder climates, there is only one which begins at the spring thaw, from mid-January to mid-February. She gives birth, after a 33 to 35 day pregnancy, in a lined den or tree hollow, to from 1 to 8 young. Litter size is typically 2 to 5. The young develop very quickly and are weaned 7 to 8 weeks after birth. At 40 days old they leave the nest. Juvenile mortality is high, with owls, hawks, and pine martens taking many individuals. About 25% survive to adulthood, which is achieved around one year after young are born. (Ruff and Wilson, 1999)

Females care for and nurse their young in the nest for 40 days. In the fall following their birth the young disperse from their mother's home range. (Ruff and Wilson, 1999)

Red squirrels can live up to 7 years in the wild, though most will die before they are 1 year old. One captive red squirrel lived 9.8 years. (Ruff and Wilson, 1999)

Red squirrels are solitary, diurnal animals that are active throughout the year. Their peak activity times are at dawn and in the late afternoon. They den in old woodpecker holes, tree hollows, or any other small crevice near their home range. In the northern part of their range, red squirrels often spend the winter in a system of underground tunnels. Red squirrels often migrate if their local food supply runs low. During these migrations they will often cross water and are good swimmers. (Ruff and Wilson, 1999)

Home ranges are usually 1 to 2.4 hectares in area. (Ruff and Wilson, 1999)

Red squirrels have keen senses of smell, sight, and hearing. They are very vocal and loudly scold intruders in their home range. Vocalizations consist of rattles, screeches, growls, buzzes, and chirps. (Ruff and Wilson, 1999)

Red squirrels are not picky eaters. They consume seeds, fruit, nuts, bark, buds, shed antlers, reptiles, insects, tree sap, pine cones, fungi (including mushrooms that are poisonous to humans), eggs, young birds, mice, and young rabbits. However, red squirrels eat primary the seeds of conifer trees. They may eat up to 2/3 of the pine seed crop in an area each year. Red squirrels store many seeds and nuts underground, in piles, or under rocks for the winter. They are able to relocate these buried seeds 30 cm underground and 4 meters below snow with their tremendous sense of smell. Many seed stockpiles are not recovered, however, making red squirrels a key tree planter and seed disperser. (Ruff and Wilson, 1999)

Red squirrels are quick and agile and can escape predators by taking refuge in thick vegetation or in the trees. Red squirrels are also fairly aggressive small animals and will defend themselves if cornered. (Ruff and Wilson, 1999)

Red squirrels can have a large impact on tree populations in two ways. They can severely limit the regrowth of conifer trees because they eat so many of their seeds. However, through their activities they also distribute the spores of beneficial fungi that help trees to acquire nutrients and grow and they accidentally plant the seeds of young trees, improving their chances of growing. Red squirrels are important prey animals for many small predators because of their abundance in the habitats in which they live. (Ruff and Wilson, 1999)

Red squirrels are beneficial because of their dispersal of tree seeds and the spores of fungi required by many trees for successful growth. About 1 to 3 million red squirrels are harvested annually for their fur in Canada, bringing in about $1 million. They are a major prey item for other economically important species such as martens, bobcats, and lynx. (Ruff and Wilson, 1999)

Red squirrels can severely damage young trees in plantations, and crops in storage. They may also gnaw on many household items and can become a nuisance if they nest in homes.

Red squirrels are common and not currently threatened throughout most of their range. A subspecies, the Mt. Graham red squirrel in southeastern Arizona, has been reduced to 150 individuals and is listed as endangered. A new observatory complex, campgrounds, and continued logging threatens its last habitat. (Ruff and Wilson, 1999)