Southern Bog Lemming

The southern bog lemming (Synaptomys cooperi) is a small North American lemming. Its range overlaps with the other species in genus Synaptomys, the northern bog lemming, in southeastern Canada but extends further south.

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. Females of this species have 6 mammae; female northern bog lemmings have 8. They are 13 cm long with a 2 cm tail and weigh about 35 gram.

These animals are found in mixed forests, wetlands and grasslands in eastern North America. They feed on grasses, other green vegetation, fungi and mosses. Their droppings are green. Predators include owls, hawks, mustelids and snakes.

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.

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.

The range of these animals is thought to be declining in some areas due to loss of wetland habitat.

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