Myopus schisticolor (Lilljeborg 1844)

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Cricetidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 955-1189 : 1030

Myopus schisticolor (Lilljeborg 1844)

[Myodes] schisticolor Lilljeborg 1844 , Ofv. K. Svenska Vet.-Akad. Forhandl. Stockholm, Part I: 33.

Type Locality: Norway, Gulbrandsdal, N end of Mjosen, near Lillehammer.

Vernacular Names: Wood Lemming.

Synonyms: Myopus middendorfii Vinogradov 1922 ; Myopus morulus Hollister 1912 ; Myopus saianicus Hinton 1914 ; Myopus thayeri G. M. Allen 1914 ; Myopus vinogradovi Skalon and Raevski 1940 .

Distribution: Coniferous taiga zone from Norway and Sweden through Siberia to Kolyma River and Kamchatka ( Nikanorov, 2000), south to the Altai Mtns, N Mongolia and NE China (N Heilongjiang and N Nei Mongol; Zhang et al., 1997), and the Sikhote Alin Range ( Corbet, 1978 c); also a southern isolate in the Ural Mtns, near source of Ural River, about 450 km south of previously recorded limit at 58ºN.

Conservation: IUCN – Near Threatened.

Discussion: Described in detail by Miller (1912 a) and Hinton (1926 a); reviewed by Gromov and Polyakov (1977) and Corbet (1978 c, 1984). Intraspecific chromosomal variation and extraordinary genetic system of sex determination leading to female-biased sex ratio documented by Gropp et al. (1976), Kozlovskij (1986), Fredga et al. (1976, 1977, 1993), and Gileva and Fedorov (1991). Departures from the usual 2n = 32 documented for Siberian samples ( Gileva et al., 1983; Kozlovsky, 1985), but the chromosomal difference does not signify more than a single species ( Jarrell and Fredga, 1993). Genetic variation is low in populations from Western Siberia and Scandinavia ( Fedorov, 1990, 1993; Fredga et al., 1993). Using isozyme analysis, Fedorov et al. (1994) recorded significant genetic divergence between the Fennoscandian, Western Siberian, and Eastern Siberian regions but little differentiation among populations within each. Age and geographic variation among Norwegian populations assessed by Kratochvíl (1979).

Courant et al. (1997) discovered cranial shape convergence between M. schisticolor and certain voles and discussed possible ecological influences for such parallel shape changes in distantly related arvicolines. Regarded as rare, but Emelyanova (1994) found wood lemmings to be a dominant species in small mammal communities of the taiga zone, NE Siberia, forming the primary food of hawk owls .