Southern bog lemming

Description

The southern bog lemmings are small mammals that are more closely related to voles. They are covered with thick brownish fur on the back ranges in color from reddish to dark brown and have a grizzled appearance. The belly is silver-gray. The grooved upper incisors and a relatively shorter tail distinguish this species from other voles. They have relatively large head and small eyes. The ears barely show through puffy head fur. The southern bog lemmings have 4 toes and 1 small, nailed thumb on the forefeet and 5 toes on the hind feet. Females have 6 mammary glands, which distinguishes this species from its closest relative, northern bog lemmings, which have 8 mammary glands. They have round thick bodies covered with grey-brown fur with silver grey underparts. They have a large head, short legs and a short tail which is lighter underneath. Their small ears are barely visible through their fur. Their upper incisors are grooved. They are 13 centimetres (5.1 in) long with a 2 centimetres (0.79 in) tail and weigh about 35 grams (1.2 oz).

Range and Habitat

Southern bog lemmings are found in eastern North America, from southern Quebec and Manitoba in Canada to western Minnesota, to southwestern Kansas, and east to the Atlantic coast of the United States. This species is more common in deciduous and mixed coniferous –deciduous forests. The grassy openings and edges of these forests, especially where sedges, ferns and shrubs grow and when the soil is loose and crumbly, are habitats the bog lemming prefers. It also inhibits wetter and drier sites when meadow voles are scarce or absent. The southern bog lemmings create a maze of interconnecting tunnels and runways and build nests from plant fibers. Summer nests are on the surface of the ground or in a clump of sedges or grasses but winter nests are usually underground in an enlarged tunnel. These animals are found in mixed forests, wetlands and grasslands in eastern North America.

Diet and feeding behavior

Fresh vegetation, especially the leaves, stems, seeds heads and roots of grasses and sedges is the main food of this species. Raspberries, blueberries and other fruits, insects, fungi and bark form a lesser part of the diet. They cache grasses and sedge stems in underground chambers. The southern bog lemmings are more active during night .They don’t hibernate. They live in groups of a few to several dozen individuals. Female lemmings have 2 or 3 litters of 4 to 6 young in a year. The young are born in a nest in an underground burrow or concealed in vegetation. Most will live less than a year. The range of these animals is thought to be declining in some areas due to loss of wetland habitat.

They are active year round, mainly at night. They make runways through the surface vegetation and also dig underground burrows. These animals are often found in small colonies. Lemming populations go through a 3 or 4-year cycle of boom and bust.

Reproduction

Breeding may occur during any months of the year if there is plentiful food. The gestation period is 21–23 days and females bear many litters in a year, each with an average of 3 young. At birth the newborns are blind and without fur. They also have claws at birth. By the end of their first week, young are well furred. They open their eyes at about 12 days of age. They are weaned at 3 weeks. Male southern bog lemmings reach sexual maturity in 5 weeks. Most individuals breed before they reach their maximum size.

Communication

Southern bog lemmings are thought to communicate using scent marking. They also make squeaking vocalizations. Other methods of communications include; acoustic, chemical, visual and tactile.

Predators

Southern bog lemmings have many predators, including owls, hawks, red foxes, gray foxes, domestic dogs, badgers, weasel, snakes, bobcats, and house cats.

Two subspecies have become extinct: Kansas bog lemming (S. c. paludis), and Nebraska bog lemming (S. c. relictus).