The snowshoe hare is also called the varying hare. This animal is rusty brown in summer but in the autumn, its guard hairs are replaced by new white hairs which give the mammal an overall white appearance. In addition to allowing this mammal to blend into a snowy landscape, the structure of the white hair includes more air which provides for greater insulation during the colder months. In early spring, the hare goes through another molt which returns it to a summer coat. During the fall molt, the fur on its feet becomes much thicker, aiding in insulation. The extra fur also allows the snowshoe hare to move easily on top of deep snow.
This species has benefited greatly from the clearing and farming of the Commonwealth.
This species was recently recognized as separate from the New England cottontail.
The woodchuck is the largest member of the squirrel family. It builds an extensive burrow system that, once abandoned, provides refuge for many other mammals. This is probably our best-known hibernating mammal.
The gray squirrel easily tolerates life around humans in parks and other small stands of trees where it may build huge leaf nests as well as denning in hollow trees.
One squirrel may bury hundreds or even thousands of nuts. Although many are found again, squirrels contribute heavily to the planting of new trees when unfound food caches sprout and grow.
This small ground squirrel builds an extensive burrow system, with multiple entrances, where large caches of food are sometimes stored. Food may also be stored in a small hole which the chipmunk excavates and then covers. Unlike the gray squirrel that hides a single acorn in each hole, large stores may be transported in the cheeks of a chipmunk for storage at a single site. Trees are sometimes climbed in search of food.
Although they are tree squirrels, these animals also burrow and may store food underground.
Not frequently seen by people, the northern and southern flying squirrels are not easily distinguished from each other at a distance. Young flying squirrels are sometimes found on the ground, in a disoriented state, after a heavy storm.
This species is common in the woodlands of southwestern Pennsylvania but it is not frequently seen because it is active at night. The animal “flies” by spreading its limbs out to the sides and flattening the furry membranes into a sail that allows it to glide down and forward for distances of up to 40 feet.
The beaver is a large rodent adapted for aquatic life. Although awkward on land, it is capable of felling trees eight feet in diameter for construction of its lodge. Details of its engineering prowess make fascinating reading. So, too, is its remarkable recovery in Pennsylvania. The beaver was trapped for its luxuriant fur by early settlers and disappeared from Pennsylvania by the mid-1800s. In the summer of 1917, a pair of beaver from Wisconsin was released in Cameron County. Within five years, the beaver populations of Cameron County and southern McKean County were well established from that original pair. That group and subsequent releases from Canada and New York in 1919, 1920, 1922, and 1924 form the nucleus of the current inhabitants in the Commonwealth.
The mysterious decline of Allegheny woodrat populations throughout eastern North America has been the focus of much research in recent years. In Pennsylvania, there are only a few known sites where woodrat dens persist. As yet, none of the theories explaining this native rat’s diminished populations has been proven.
Found throughout the Commonwealth, this is one of the most common mammals in Pennsylvania.
There are three different subspecies of deer mouse that occur in Pennsylvania. The two most abundant varieties prefer a woodland habitat. The third subspecies prefers open fields and other areas with little cover.
Like many herbivores, this mouse will gnaw on bones and deer antlers to obtain calcium.
This species has often been linked to the long-tailed or rock shrew Sorex dispar because of their common preference for rocky habitats. This vole looks a great deal like the more common meadow vole, except for the distinctive yellow splash of color across its nose and cheeks.
One of the most abundant and widespread mammals in the Commonwealth, it serves as prey for carnivores as tiny as the least weasel and as large as the black bear.
This mammal builds a large network of subterranean tunnels where it caches food for the winter. It can be a serious agricultural pest when it girdles orchard trees in order to consume the bark during the winter months.
This rodent is well adapted to semiaquatic life but is not closely related to the beaver. It, too, is valued for its fur. One of its chief enemies is the mink.
Although this mammal looks similar to several of the voles that occur in the Commonweath, it can be distinguished by its grooved upper incisors, extremely short tail, and grizzled, gray-brown fur.
This tiny rodent is reported to be an excellent swimmer.
Porcupines cannot throw their quills, but as the tail is swished violently to threaten an enemy, loosely attached quills may fall off the body. Young are born with soft, short quills that dry and stiffen within a few hours.
The original elk herd disappeared from Pennsylvania in the late 1800s. Today, the Game Commission manages a reintroduced herd in McKean, Elk, and Cameron counties.
This is undoubtedly our most popular game species. The spots found on a white-tailed deer fawn represent a form of cryptic coloration. Meant to simulate the appearance of sunlight filtering through trees onto the forest floor, a fawn can go undetected while lying motionless only a few feet from a potential predator.