Southern bog lemmings are found in eastern North America, from southeast Canada to western Minnesota, down to southwest Kansas and east to northeast North Carolina.
Synaptomys cooperi occurs mainly in sphagnum bogs, as its common name suggests, but it may also occur in grasslands, and in Canada it occurs in coniferous or deciduous forests. In Michigan, it can be found in clear cuts, old fields, or upland woods. Occurrence within the larger geographic range is patchy--it tends to occupy isolated areas. This is thought to be due to competition with meadow voles.
Southern bog lemmings are small voles, weighing 20 to 50 grams and measuring 110 to 140 mm in total length. The dorsal pelage ranges in color from a chestnut to dark brown that has a grizzled appearance. The venter is silver-gray. Females of this species have 6 mammae, which differentiate it from its closest relative, Synaptomys borealis, which have 8 mammae. The orange incisors are broad and longitudinally grooved. The tail is short, barely longer than the hind foot.
Breeding occurs in all seasons, especially where food is not limiting. Most young are born between April and September. Females are polyestrous--one captive bore 6 litters in 22 weeks. Wild females produce 2 or 3 litters per year. Gestation lasts from 23 to 26 days. Mean litter size is 3 but can range from 1 to 8. Males can reach sexual maturity in 5 weeks.
Southern bog lemmings weigh 3.7 grams at birth. Young are born with no fur, closed eyes, and with the ear pinnae folded over. Claws are apparent at birth. By the end of the first week, the young are well furred. The female nurses her young for three weeks.
Wild southern bog lemmings usually do not live for more than a year. In captivity, they may live up to 29 months.
Not much is known about social interactions of southern bog lemmings. Population density can range from 6 to 35 individuals per hectare. Synaptomys cooperi does not hibernate and can be active any time of day or night, but is mostly nocturnal. It makes runways and tunnels or uses those of other species. It also builds nests from dry grasses which are concealed under stumps or sphagnum mounds.
There is thought to be intraspecific communication in the form of scent marking from anal secretions. Vocalizations are squeaks.
Southern bog lemmings eat mostly vegetation such as grasses, sedges, mosses, fruits, fungi, bark and roots. Bog lemmings snip stems near the ground to get access to the upper parts. Often surrounding vegetation prohibits the stems from falling, so additional snips must be made. Some invertebrates such as slugs and snails are also taken. The jaws are powerful and thought to be used extensively for gnawing.
Once very common, numbers seem to be declining as a result of habitat destruction and the overgrowth of bogs. One subspecies, Synaptomys cooperi helaletes, is thought endangered and possibly extinct. Other subspecies also appear to be threatened.
Allison Poor (editor), University of Michigan-Ann Arbor.
Bridget Fahey (author), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.
uses smells or other chemicals to communicate
active at dawn and dusk
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
an animal that mainly eats leaves.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
An animal that eats mainly plants or parts of plants.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
breeding takes place throughout the year
Linzey, A. V. 1983. Syamptomys cooperi. Mammalian Species, no. 210: 1-5.
Kurta, A. 1995. Mammals of the Great Lakes Region. University of Michigan Press, Ann Arbor MI
Nowak, R.M. Walker's Mammals of the World, 5th Edition. Johns Hopkins University Press.
"Animal Life Histories Database" (On-line).
Ruff, S., D. Wilson. 1999. The Smithsonian Book of North American Mammals. Washington [D.C.]: Smithsonian Institution Press in association with the American Society of Mammalogists.