Red squirrels are diurnal (active during the day) although they may occasionally be active during the night. Activity patterns are strongly influenced by weather patterns; high winds, rain, snow, and low temperatures reduce activity. Red squirrels do not hibernate during the winter months and most activity during this time of year occurs during mid-day hours when temperatures are highest. In summer the squirrels are most active during early morning and late afternoon hours, and in the spring and fall activity levels are equally distributed throughout the daylight hours.

Red squirrels are highly territorial and will vigorously defend the area surrounding their hoard of food by using territorial vocalizations and by chasing intruders away. They not only attempt to keep red squirrels and other competitors at bay, but also exhibit territorial defense behaviors against predator species. The most common territorial behavior is a vocalization called a chatter (or rattle) call. This vocalization serves to announce the presence of an individual to its neighbors, warning them to stay away and avoid costly aggressive encounters.

Common Red Squirrel Vocalizations

Vocalization Name


chatter or rattle

territorial defense, announce presence, signature call for individual recognition

bark or chirp

Alarm call, indicate presence of predator


used alone or with chatter in defense


aggressive defense, used during chases and fights


indicates agitation, often precedes chirps


mating, by male approaching female


Chatter calls are often used: when a squirrel first emerges from its nest, when it returns to its territory, after caching food or feeding, and upon sighting an intruder. Barks are most often given in long series, sometimes lasting for several minutes up to an hour. Squeaks are given in response to a potential threat and increase in intensity if the threat does not diminish. They often progress into barking sessions. Growls are most commonly heard during chases and fights over territories or females. Squirrels caught in live traps will also growl when approached. The squeak and buzz calls are the first calls developed by juveniles and are used to call to their mother


Feeding Habits

Red squirrels feed mainly on seeds of coniferous trees, but they also eat mushrooms, insects, bird eggs, nestlings and a wide range of other items. In coniferous forest habitats, red squirrels create "middens", which are the accumulation of cone scales and debris left from feeding. They typically only feed at one or two favorite places within their territory and the debris can pile up to considerable depths.

The midden is used as a storage area, for caching cones, and it likely provides a cool, moist microenvironment which facilitates seed storage. The midden, the territory surrounding the midden, and the center of activity are vigorously defended from all intruders. Each territory (midden site) is occupied by a single squirrel, with the exception of females with young. Midden sites may be occupied by a succession of different squirrels for decades.

Nesting Behavior

Red squirrels use three general types of nests:

Cavity nests - are made inside hollow dead trees (snags) and appear to be the preferred nest type, especially for giving birth to and rearing young.

Bolus nests - are constructed from grass, lichen, leaves, and sticks and are formed into a ball then placed on a branch or branches of a tree.

Ground nests - Are located in underground tunnels, often tunnels left from a rotted tree root system. Nests are often constructed under logs covered with deep snow. These nests are only used for one winter and provide easy access to the squirrels' food caches as well as protection from predators and the weather.