Category Archives: Mammals

Least chipmunk (Neotamias minimus)

least chipmunk
Photo by Ramona Abrego

Least chipmunk (Neotamias minimus) is the most widespread and also the smallest of the North American chipmunks. In Canada it occurs from Ontario to Yukon Territory. In the United States it occurs west of the Great Plains and in the upper Great Lakes region. In Minnesota it occurs in the Arrowhead and north-central regions. It is found at the edges and in the openings, clearcuts, and disturbed areas of coniferous and mixed forests. It eats seeds, nuts, fruits, acorns, snails, insect eggs and larvae, and small birds and mammals. It nests under stumps, logs, and rocks. It winters in a burrow it digs that reaches up to one meter underground. When running it holds its tail erect.

The adult is 7¼″ to 8¾″ long. It weighs about half as much as an eastern chipmunk. The coat (pelage) on the sides is reddish-brown in the front, grayish brown in the rear. The rump is grayish-brown. There are five dark brown or black stripes on the back separated by white or cream-colored stripes. The middle stripe stretches from the nape of the neck to the base of the tail. On each side of the face there are three dark brown stripes separated by two white or cream-colored stripes. The facial stripes are well defined and highly visible. The tail is orangish-brown, and bushy.

Franklin’s ground squirrel (Poliocitellus franklinii)

Franklin’s ground squirrel
Photo by Lynn Rubey

Franklin’s ground squirrel (Poliocitellus franklinii) is a medium-sized squirrel but a large ground squirrel. It is the largest and darkest ground squirrel in its range. It occurs in the tallgrass prairie region in the United States and Canada. It is considered scarce in Minnesota. It is found in areas with tall vegetation including edges of fields and prairies, open woodlands, and edges of marshes.

Franklin’s ground squirrel is superficially similar in appearance to an eastern gray squirrel but it is smaller and has a shorter, less bushy tail, shorter ears, and a more pointed snout. The coat (pelage) is short and dark gray with pale and dark flecks and a brown wash over the back and rump.

Franklin’s ground squirrel spends most of its time in an underground burrow that can be up to 8 feet deep. It is tolerant of humans and can be seen at camp sights, in state parks, and at dumps. It is omnivorous, feeding on plants, ground nesting bird eggs, insects, and small animals, including other ground squirrels.

American badger (Taxidea taxus)

American badger

Photo by Wayne Rasmussen

American badger (Taxidea taxus) is a solitary, medium-sized, common but seldom seen, carnivorous mammal. It is a solitary animal, active mostly at night but also often during the day, especially in early morning. It has a home range of about 1 square mile in which it may have up to 46 burrows. It is a good digger, the only mammal that can dig out pocket gophers. It eats mostly ground squirrels and pocket gophers, but also voles, mice, reptiles (including rattlesnakes), amphibians, ground-nesting birds and their eggs, insects, and other invertebrates.

Badgers are easily recognized. The low, flattish profile and white middorsal head stripe are diagnostic. The common name is thought to refer to the black “badge”-shaped markings on their cheeks. There are four, fifteen, or twenty-one subspecies of badger in North America, depending on who you ask. All sources recognize the two subspecies found in Minnesota. Common badger, the largest subspecies, is found in the western border counties. Jackson’s badger, typically darker and smaller, is found in the remainder of the state.

Northern short-tailed shrew (Blarina brevicauda)

northern short-tailed shrew

Photo by Bill Reynolds

Northern short-tailed shrew (Blarina brevicauda) is the only poisonous mammal on the North American mainland. Its poisonous bite allows it to paralyze its prey and eat it at a later time. It is sufficiently strong to kill animals up to the shrew’s size, and to produce a very painful reaction in humans who handle the shrew.

It has a poor sense of smell and very poor vision. It can navigate and detect objects in its environment using echolocation and and touch. Like bats, it emits a series of ultrasonic squeaks to detect its surroundings. Unlike bats, it does not use echolocation to locate prey. Its snout and whiskers are highly sensitive to touch.

There are 385 species of shrew worldwide, 7 in Minnesota. Northern short-tailed shrew is the largest and most widespread in eastern North America and the most common in Minnesota. The combination of large size and short tail distinguish this from all other shrew species in Minnesota.

Southern red-backed vole (Myodes gapperi)

southern red-backed vole

Photo by Kirk Nelson

There are six species of voles found in Minnesota. Southern red-backed vole (Myodes gapperi) is one of the smallest. It is common in moist deciduous, coniferous and mixed forests with stumps and logs for ground cover. It is usually the most common rodent in cedar, tamarack, and black spruce swamps. It is active both during the day and at night but more often at night. It is solitary, not forming colonies or pair bonds. It forages mostly on the ground but also in trees. This is the only vole in Minnesota that is a good climber of trees.

Southern red-backed vole is distinguished from mice by a stouter body; shorter, hairy tail; smaller ears and eyes; and molars with high crowns and angular cusps. It is easily distinguished from other voles by the gray sides and reddish back.

Eastern red bat (Lasiurus borealis)

eastern red bat

Eastern red bat (Lasiurus borealis) is a medium-sized hairy-tailed bat. In their definitive work on eastern mammals, John O. Whitaker, Jr., and William J. Hamilton, Jr. describe it as “one of the most beautiful of all American bats.” It is widespread in Minnesota but not common. It is found in trees near open areas.

During the day they hang by their feet in a tree or shrub with dense foliage above and to the sides but clear below, leaving a clear flight path. They for just a few hours beginning at dusk. They locate their prey both by echolocation and by sight. Males and females have different summer ranges. They are solitary individuals but come together to migrate in flocks of up to several hundred individuals. They head south for the winter but their wintering range is unknown.

Bats are important vectors of the rabies virus but rabid bats pose little threat to humans. They are passive, will not attack, and will not bite unless handled.

Eastern red bat is named for the brick-red fur of the male. It is further distinguished from other bats in Minnesota by white shoulder patches, long tail not extending beyond the wing-like flight membrane, flight membrane near the tail densely furry above, tail hairy above, and the projection partially covering the ear opening hairy at the base.

Prairie deer mouse (Peromyscus maniculatus bairdii)

prairie deer mouse

Photo by Kirk Nelson

North American deer mouse (Peromyscus maniculatus) is common and widespread in North America. It is probably the animal most responsible for the transfer of the deadly hantavirus to humans in the central and southwestern United States. The species is recognized by its small size and its sharply bicolored tail.

There are 67 currently recognized subspecies of Peromyscus maniculatus in North America. Two of these occur in Minnesota.

Prairie deer mouse (P. m. bairdii) is found on grasslands and agricultural fields. This subspecies is recognized by its smaller size, its shorter tail, and its preference for grassland habitats.

Don’t Eat the Blue Snow

Minnesotans “of a certain age” will remember roadside billboards with nothing but the words “Don’t Eat the Yellow Snow.” The billboards were a (stealth?) advertising campaign by Rudy Boschwitz’s Plywood Minnesota. It was a long time ago and a Google search does not return any relevant results. But you may want to add blue to the snow colors to avoid eating.

Don't eat the blue snow!

Don’t eat the blue snow!

In the late winter when there is usually very little for deer to eat they begin to browse on common buckthorn, a plant they normally avoid. Common buckthorn contains a chemical that is expelled with the urine. The tainted urine is initially yellow or brown but, after exposure to about ten minutes of sunlight, turns bright blue or sky blue.