Dicrostonyx groenlandicus (Traill, 1823)

Wilson and Reeder (1993) list four species that would occur in Alaska:

Dicrostonyx exsul G. M. Allen, 1919 - St. Lawrence Island collared lemming
Dicrostonyx nelsoni Merriam, 1900 - Nelson's collared lemming
Dicrostonyx rubricatus (Richardson, 1889) - Bering collared lemming
Dicrostonyx unalascensis Merriam, 1900 - Unalaska collared lemming

In doing this, they formalize the suggestion of Rausch & Rausch (1972) that many of the North American chromosonal races represent full species. We follow the view of Jarrell & Fredga 1993, that the Alaska forms are Dicrostonyx groenlandicus.

Species diagnosis

General Characteristics

Cheek teeth longitudinally complex (many loops)
Inner and outer salient angles approximately equal in size
m1 with 7 closed triangles between terminal loops
Supraorbital ridges strong but not fusing in interorbital region

Alaska subspecies

Subspecies	Type Locality
Dicrostonyx groenlandicus exsul G. M. Allen	St. Lawrence Island, Bering Sea
Dicrostonyx groenlandicus nelsoni Merriam	St. Michael, Norton Sound
Dicrostonyx groenlandicus peninsulae Handley	Near sea level at Urilla Bay, Unimak Island
Dicrostonyx groenlandicus rubricatus (Richardson)	American side of Bering Strait
Dicrostonyx groenlandicus stevensoni Nelson	Umnak Island
Dicrostonyx groenlandicus unalascensis Merriam	Unalaska

Literature Cited

Jarrell, G. H. & K. Fredga. 1993. How many kinds of lemming? A taxonomic overview. In:
N. C. Stenseth & R. A. Ims, The Biology of Lemmings, Academic Press, pp 45-57.
Rausch, R. L. & V. R. Rausch 1972. Observations on chromosomes of Dicrostonyx
torquatus stevensoni Nelson and chromosomal diversity in varying lemmings. Zeitschrift
fur Saugetierkunde 37:372-382.