There are several species of squirrel, including the ground, gray and flying squirrels. Many squirrel species live in tree tops and scamper on the ground in pursuit of a potential mate or foraging for nuts and foodstuffs, but there are also species of squirrel such as the Eastern chipmunk (Tamias striatus) that are primarily ground dwellers. Most squirrel species are considered pests because they can quickly and severely deplete agricultural crops such as corn. The different species of squirrels occupy different types of habitats, which puts them at risk for several types of predators.
Hawks and Owls
The lined ground squirrel (Spermophilus tridecemlineatus) inhabits fields, prairies and agricultural lands in Minnesota and other mid-western states making it prey to large predatory birds. Hawks and owls can swoop down while grounds squirrels dart between feeding on acorns and insects. Some species of hawks that commonly feed on squirrels are the red-tailed and Coopers hawk. Some species of owls that will feed on various species of squirrel are the great horned owl and the barred owl.
Coyotes, Snakes, Raccoons and Weasels
Coyotes will also feed on the woodchuck (Marmota monax), also known as the ground hog as it forages on grasses and clover. Raccoons and weasels feed on various species of squirrel depending on which part of the United States they inhabit. The rattlesnake feeds on ground squirrels in Northern California as they forage for food in dense woods and burrow 2 to 4 feet into moist soil conditions building complex chambers up to 30 feet in length.
Foxes, Bobcats and Eagles
The eastern grey squirrel (Sciurus carolinensis) forages the ground for acorns, seeds, buds and flowers only in the eastern part of the United states, thus making is susceptible to predators such as the red and gray fox species. This particular species of squirrel inhabits hardwood forests and is uncommon in the coniferous forests of Minnesota. Eagles will commonly feed on ground squirrels that inhabit Northern California, as well.
Cats and Dogs
Although cat and dogs are considered predators, they may not feed on the squirrel species they hunt and chase unless they are hunting under feral (wild) conditions. And, even though dogs and cats will "prey" on squirrel species, they are not considered effective methods in controlling squirrel populations.
Squirrels are also susceptible to parasites and skin diseases that are fatal, and thus can be considered a predator of squirrel species. The scabies mite is a parasite that causes mange; in turn the squirrel scratches until it is bleeding and hairless. As a result of the mite, the squirrel becomes unable to fight off the elements or predators. Another parasite that can be fatal to squirrels is the warble fly. The adult fly lays an egg inside the bark of trees, and the larvae latch on to squirrels and burrow into the skin.