Tamiasciurus hudsonicus
(Red Squirrel)


Order:Rodentia
Order Description:Rodents
Family: Sciuridae
Family Description: Chipmunks, Marmots and Squirrels

Description:
The red squirrel, also known as the chickaree, is brownish red to rust red on its upper half with a white ventral side separated from the top by a dark stripe. It has a light colored eye ring which is easy to see when observing the squirrel, and its tail is bushy but not large and prominent like those of other tree squirrels, the outer edge of the tail has a black band edged with white. Behaviorally, it is quick and energetic with jerky and very busy movements.

Range:
From Alaska, east to Newfoundland, south to Smoky Mountains, and south through Rocky Mountains to Arizona and New Mexico.

Habitat:
The red squirrel is found throughout the northern borealClick word for definition forest across Canada and the northern tier of states, much like the northern flying squirrel. They prefer coniferousClick word for definition and mixed forests, but is frequently found in deciduousClick word for definition woodlots, hedgerows, and second-growth areas. Ideal habitat seems to be spruce-fir forests, and the seeds in spruce cones especially are preferred. In Idaho, found in all coniferous forests, mixed forests, and riparianClick word for definition woodlands adjacent to conifers. Young are typically forced into marginal, deciduous forests such as aspen in Idaho.

Diet:
They commonly eat seeds of conifer cones, nuts, fungi, and fruits. Their propensity to eat conifer seeds is a hallmark of their activity and influence on forest ecosystems. They occasionally feed on invertebrates. Recent research in Canada documented that they prey on bird eggs, young birds and even on newly born snowshoe hares.

Ecology:
Like most tree squirrels they are diurnalClick word for definition with peak activity in morning 2 hours after sunrise and evening before sunset. They are usually conspicuous throughout day. They are capable climbers and can easily leap from limb to limb. Because they do not hibernateClick word for definition they store food for the winter. During a 4 to 6 week period in the fall, spruce, fir, and pine cones are fully developed and the seeds in the cones are mature. Red squirrels cut cones from conifer trees and cacheClick word for definition them in storage areas called middensClick word for definition. The middens, often 15 by 30 feet or even larger, are formed over numerous years by continuous storage and feeding activity. As the midden owner feeds, rapidly extracting the numnerous seeds from each cone with its teeth, the cone bracts are stripped off and fall onto the midden. Many middens have a 12 inch layer of cone bracts on top of moist soil. This medium provides an ideal location for the storage of many cones in holes and depressions dug into the midden. Red squirrels also store cones in small depressions in the ground away from their middens, Red squirrels do all of their storing of cones during a 4 to 6 week period in the early fall. If the cones are not cut from the tree during a critical period when the seeds are fully developed, the bractsClick word for definition of many cones open and the seeds are dispersed by the wind. If they are cut from the tree and left lying on the ground, the cones dry out and open up, again allowing the seeds to disperse. Squirrels prevent this by storing the cones they cut in their moist caches or middens, where they are tightly packed into holes like dill pickles in a jar. Middens tend to be near the center of the squirrel's territory, which is about .5 to 1.5 ha (1 to 4 acres). Red squirrels may be the most territorial mammals in Idaho. During the fall cone cutting and storing creates a flurry of activity that can result in the storage of up to 20,000 cones. Squirrels will cut cones from near the tops of trees for 5 or 6 minutes, then descend and carry them into their middens. They rarely carry cones farther than 30 yards from their middens. Cone crop failures often force the squirrels to use year old or older cones from their stores, but only the larger middens seem to hold more than one winter's supply of food. The red squirrel's territorial call is easy to hear and consists of a long churr---of 1 to 4 seconds duration. Similar to territorial songs in birds, the squirrel's call advertises its presence in its territory. Failure to periodically call usually results in an invasion of territory by a neighboring squirrel. This behavior is most pronounced during the fall food storing period, but it also continues throughout the year. They commonly cache more food than it can consume in a winter, which leaves cones for the next year in case of a cone crop failure. Early foresters in Idaho would collect cones and their seeds from red squirrel middens for their tree nurseries. This cone storing behavior also has economic value in seed dispersal in forests. Population densities range from about 1/3.2 ha (Pinaleno Mountains, southeastern Arizona) to 1/0.2 ha. More territorial than most other North American tree squirrels. Populations in British Columbia are limited by food (acting through effect on reproduction). Red squirrels are ecologically connected to grizzly bears in Idaho. Red squirrels at higher elevations collect and store whitebark pine cones in their middens. In the fall grizzlies seek out these middens where they eat the whitebark seeds from the cones stored by the red squirrel. Of course that is tough on the red squirrel who spent a great deal of energy storing up its own winter food supply. But they cannot argue with a grizzly bear.

Reproduction:
Breeds March-April and June-July. Female is in estrusClick word for definition only for 1 day. GestationClick word for definition lasts 31-35 days. Some females produce 2 litters/yr. litterClick word for definition size averages 4-5 young. Some females breed when less than 1 yr old.

Conservation:
Status: Protected nongame species

Global Rank:

G5

State Rank:

S5

Important State References:
Medin, D.E. 1986. The impact of logging on red squirrels in an Idaho conifer forest. West. J. Appl. Forestry 1:73-76.


Information written by Donald Streubel,© 2000
Map image provided by
Stephen Burton,© 2000
Design by Ean Harker©1999, 2000.