Part 7

Chipmunks are chiefly terrestrial in habit although they can and do frequently climb into low trees and bushes. The different species of Western Chipmunks vary greatly in their preferred habitat from sagebrush flats to heavily wooded areas. Each type of environment has its distinct type of chipmunk.

The color patterns of the chipmunks vary, each type having its own distinctive pattern; however, the group as a whole is distinguished from other squirrels by the stripes on both body and face. The smaller ground squirrels may have some stripes on the body but do not have striped faces.

Chipmunks are universal favorites with visitors. Lively, interesting, and full of curiosity, they are quite easily tamed and soon learn to frequent the picnic areas and campgrounds. Here they take their toll of food bits from each group of people, either eating it on the spot or carrying it away to store for future use.

Their food consists mainly of seeds, berries, nuts, buds, some insects and any food scraps they may chance to find around camps. Their winter stores are located close to their nest, in underground cavities.

The chipmunks are not active outside during the stormy periods of winter but since they do not become fat in the fall and use some of their food stores during the winter it is not thought that they go into a complete period of hibernation like some of the other animals. Exactly what they do and how they live in Yellowstone during the winter, however, remains yet to be determined.

Their nest is made underground as they burrow into the earth at the foot of a stump, log or rock. In this nest the litter of four to six young are born in the spring. It is not likely that they have more than one litter a year here in the north.

The following forms of Chipmunks are found in Yellowstone Park:

Buff-bellied Chipmunk—Eutamias amoenus luteiventris

This is the abundant little striped chipmunk seen throughout most of the park along the roads and trails and around camp sites. Upper parts with five dark and four light longitudinal stripes from shoulder to base of tail. Median stripe from crown to root of tail. Whitish stripes bordered by dark, above and below eye. Underparts buffy; color rich; 8½ inches over-all length.

Uinta Chipmunk—Eutamias umbrinus

Generally scattered over the park but not as common as the above. Larger in size, 10 inches over-all length; under parts whitish and stripes not as conspicuous as in the Buff-bellied.

Wasatch Chipmunk—Eutamias minimus consobrinus

These little chipmunks were reported by Bailey to be found near Yellowstone Lake and near the eastern and southern boundaries of the park in high, open valleys. They are hard to distinguish from the buff-bellied chipmunk, as their white belly is somewhat concealed. They are slightly smaller in size. A gray form of this species has been reported from Swan Lake Flat but it is probably rare.

PINE SQUIRREL Wind River Mountains Red Squirrel, or Chickaree Tamiasciurus hudsonicus ventorum

These little animals are abundant throughout the forested sections of the park. Lively and noisy, they immediately give voice to a tirade of scolding and chattering at the approach of an outsider to their domain.

Friendly by nature they become quite tame wherever the park visitors are found, especially such areas as provide an opportunity to pick up chance bits of food. Alert and inquisitive they pry into anything that attracts their attention.

This squirrel has been frequently accused of destroying the nests of its bird neighbors and eating the eggs and young. This is true to some extent, especially among certain individuals. However, some of this damage is compensated by their unintentional benefit in assisting in reforestation. Cones and seeds that are buried for winter use are frequently overlooked and some of these later germinate and grow.

Pine squirrels do not hibernate during the winter and are active at all times except during periods of storms. They build warm nests either in hollow trees, woodpecker holes, or balls of leaves and fibers firmly anchored among the branches of a tree. They industriously collect large stores of cones for the winter food supply. These are either stored in hollows or more often buried in storage pits in the ground. After the ground is covered with its winter blanket of snow the squirrels make numerous tunnels under the snow which gives them access to the storage places and act as a protected place where they can scamper about.

The young are usually born in May or June, and number four or five to the litter with seldom more than one litter a year. Young squirrels are blind, naked and helpless for several weeks after birth.

A pine squirrel’s diet consists of nuts, seeds, berries, inner aspen bark, mushrooms, and some animal food such as birds’ eggs and fledglings.

Its enemies are hawks, owls, pine martens and weasels, and occasionally the larger carnivores.

General description: A small arboreal squirrel with flat, bushy tail; fairly long ears and fairly long pelage. Dark olivaceous with white underparts in summer, while in winter it is rusty-red above, sides olive-gray and underparts gray. Sexes alike. Total length about 13½ inches, tail over ⅓ of the length.

Where found: Abundant in all forested areas. Active during the daytime only.

Beaver Castor canadensis missouriensis

The quest for the fur of this little wilderness engineer did more to bring about the exploration of the west than any other one factor. The first daring explorers were continually pushing ever forward into the unknown regions searching for the wealth of furs and establishing the fur trade with the Indians. Thus, the first white man known to have entered the region later known as Yellowstone Park was John Colter, the representative of a fur trader.

These activities greatly depleted the beaver populations but under protection in recent years they have staged a satisfactory recovery in many parts of their former range.

The dams constructed by this animal are well known. Made of sticks, logs and mud, they are a remarkable accomplishment. The dam is for the purpose of impounding a pond of water in which to construct the beaver lodge or house. This also is made of sticks and mud with a room in the middle, above water level, reached by several underwater passages. The pond must be of sufficient depth to provide plenty of water below the level of the winter ice.

Sometimes when suitable ponds or still water are available the beaver digs a sloping tunnel into the bank of a stream, with a room at the end and above the high water level.