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.
New World rats and mice (Cricetidae)
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.