27.

Northern Bog Lemming

Synaptomys borealis

French: Lemming boréal / German: Nordlicher Moorlemming / Spanish: Lemming de pantano septentrional

Other common names: Okanagan Bog Lemming

Taxonomy. Arvicola borealis J. Richardson, 1828, “Great Bear Lake,” District of Mackenzie, Canada.

Nine subspecies are recognized.

Subspecies and Distribution.

S.b.borealisJ.Richardson,1828—NorthwestTerritories,extremeSWNunavut,NEBritishColumbia,N&CAlberta,WSaskatchewan,andNManitoba,Canada.

S.b.artemisiaeR.M.Anderson,1932—extremeSCBritishColumbia,Canada.

S.b.chapmani].A.Allen,1903—SEBritishColumbiaandSWAlberta,Canada,andNEWashington,NIdaho,andNWMontana,USA.

S.b.dalliMerriam,1896—C,SC,&SWAlaska,USA,andYukonandN&CBritishColumbia,Canada.

S.b.innuitusTrue,1894—NQuebec,Canada.

S.b.medioximusBangs,1900—NEQuebecandLabrador,Canada.

S.b.smithiR.M.Anderson&Rand,1943—N&ECSaskatchewan,mostofManitoba,andNOntario,Canada,andNENorthDakotaandNWMinnesota,USA.

S.b.sphagnicolaPreble,1899—SEQuebecandNewBrunswick,Canada,andMaineandNewHampshire,USA.

S. b. truei Merriam, 1896 — SE Alaska, coastal British Columbia, and NW Washington.

Descriptive notes. Head-body 93-113 mm, tail 17-27 mm; weight 27-35 g. Northern Bog Lemmings vary substantially in morphology across their distribution. They are smallto medium-sized, and tail is bicolored and short. Dorsum is grizzled gray to brown, with some black hair interspersed, and venter is plumbeous. Feet are gray to near black. There are a few hairs at bases of ears that are distinctly brighter than rest of pelage. Females have four pairs of nipples. Lower molars do not have closed triangles on labial sides and almost no outer reentrant angles. Lower incisors are relatively slender and sharply pointed. Posterior edge of palate has a noticeable spinous process.

Habitat. Wet habitats with sedges and grasses in riparian zones, meadows and bogs in pine, spruce-fir, or spruce-cedar forests. Northern Bog Lemmings also can be found in wet tundra and successional grasslands after forest fires. In contrast, subspecies artemisiae lives in arid sagebrush habitat of the Okanagan Valley of south-central British Columbia.

Food and Feeding. Northern Bog Lemmings eat grasses, sedges, and other vegetation.

Breeding. Northern Bog Lemmings breed in May—August. Gestation is probably about c.3 weeks.Litters have 2-8 young; a female can produce multiple litters each year, and young females usually have 1-2 litters in their first year.

Activity patterns. Northern Bog Lemmings are reported nocturnal and diurnal throughout the year. Northern Bog Lemmings use surface runways but are also fossorial, living in burrow systems up to 30 cm deep and sometimes in small colonies.

Movements, Home range and Social organization. Home ranges vary with habitat but are likely less than 0-5 ha. Young are born in concealed nests aboveor underground.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Clough & Albright (1987), Hafner et al. (1998), Hall (1981), Linzey & NatureServe (Reichel & Hammerson) (2008), MacDonald & Cook (2009), Musser & Carleton (2005), Wilson & Ruff (1999).