Dicrostonyx unalascensis
| Unalaska Collared Lemming
(Dicrostonyx unalascensis) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Myomorphi |
| Superfamily: | Muroidea |
| Family: | Cricetidae |
| Subfamily: | Arvicolinae |
| Tribe: | Dicrostonychini |
| Genus: | Dicrostonyx |
| Subgenus: | Dicrostonyx (subgenus) |
| Binomial details | |
| Dicrostonyx unalascensis C. H. Merriam, 1900 | |
| Other resources | |
| Full taxonomic details at MDD | |
The Unalaska Collared Lemming (Dicrostonyx unalascensis) is a lemming that inhabits several of the Aleutian Islands of western Alaska. Members of the genus Dicrostonyx are the only rodents in North America that turn white in winter.
Description
From Handley (1953): "Adult summer coloration: Red of flanks extending prominently as a wash on dorsum; subapical orange bands of dorsal hairs wide; black tips of dorsal hairs narrow; total color effect of dorsum reddish-brown, between Tawny and Orange-Cinnamon; nape and cheeks buffy, poorly distinguished from dorsum; ear patched about Sanford's Brown; black median dorsal stripe pronounced; feet and tail whitish; underparts between Pale Yellow-Orange and Light Buff; throat collar wide and dark, but poorly defined (about Amber Brown); well defined ventral stripe of same color extending from collar to middle of belly. Juvenal summer coloration: Dorsum dark and bright, between Cinnamon-Brown and Dresden Brown in mass effect; cheeks and ear patches similar to remainder of dorsum; black median dorsal stripe well developed; underparts buffy, with poorly defined brownish collar. Winter pelage: At least some individuals white."
Members of genus Dicrostonyx are the only rodents in North America that turn white in winter.
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
| Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
|---|---|---|---|---|---|---|
| Alaska (Unimak Island) | Handley (1953) | 130–133 (n=3, including type) | 11–18 (n=3, including type) | 19–19 (n=3, including type) |
Skull
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Holotype: USNM 235552. Dicrostonyx unalascensis stevensoni. Adult female. Umnak Island, Aleutian Islands, Alaska. Collected 14 December 1920. Dorsal view of the skull. -
Holotype: USNM 235552. Dicrostonyx unalascensis stevensoni. Adult female. Umnak Island, Aleutian Islands, Alaska. Collected 14 December 1920. Ventral view of the skull. -
Holotype: USNM 235552. Dicrostonyx unalascensis stevensoni. Adult female. Umnak Island, Aleutian Islands, Alaska. Collected 14 December 1920. Lateral view of the skull. -
Holotype: USNM 235552. Dicrostonyx unalascensis stevensoni. Adult female. Umnak Island, Aleutian Islands, Alaska. Collected 14 December 1920. Dorsal view of the mandible. -
Holotype: USNM 235552. Dicrostonyx unalascensis stevensoni. Adult female. Umnak Island, Aleutian Islands, Alaska. Collected 14 December 1920. Lateral view of the left mandible. -
Holotype: USNM 99622. Dicrostonyx unalascensis unalascensis. Adult. Unalaska [Island, Aleutian Islands], Alaska. Collected 8 July 1899. Dorsal view of the skull. -
Holotype: USNM 99622. Dicrostonyx unalascensis unalascensis. Adult. Unalaska [Island, Aleutian Islands], Alaska. Collected 8 July 1899. Upper molars. -
Holotype: USNM 99622. Dicrostonyx unalascensis unalascensis. Adult. Unalaska [Island, Aleutian Islands], Alaska. Collected 8 July 1899. Lateral view of the left mandible.
Similar species
References
Handley CO. 1953. Three new lemmings (Dicrostonyx) from arctic America. Journal of the Washington Academy of Sciences 43(6):197-200.
Merriam CH. 1900-03-14. Papers from the Harriman Alaska Expedition. I. Descriptions of twenty-six new mammals from Alaska and British North America. Proceedings of the Washington Academy of Sciences 2:13-30.