Dicrostonyx unalascensis, Merriam, 1900

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 204-535 : 299

40.

Unalaska Collared Lemming

Dicrostonyx unalascensis

French: Lemming des Aléoutiennes / German: Unalaska-Halsbandlemming / Spanish: Lemming de collar de Unalaska

Other common names: Umnak Island Collared Lemming

Taxonomy. Dicrostonyx unalascensis Merriam, 1900 , “Unalaska, Alaska,” USA.

Dicrostonyx unalascensis is considered a subspecies of D. groenlandicus by some authorities, but karyology and breeding studies have led to recognition of D. unalascensis as a distinct species by others. Additional systematic work is needed to fully understand species limits within the D. groenlandicus complex. Monotypic.

Distribution. Unalaska I in Aleutian Is of Alaska.

Descriptive notes. No specific measurements are available. The Unalaska Collared Lemming is larger and paler than other species of Dicrostonyx and is not seasonally dimorphic. In winter, it does not turn white or develop digging claws. Few specimens of Unalaska Collared Lemmings are known (two were collected in 1931 and two in 1964), but several skulls have been salvaged from owl pellets from the island.

Habitat. Sandy or rocky beach soils. The Unalaska Collared Lemming uses burrowsit digs to rest and escape predation.

Food and Feeding. The Unalaska Collared Lemming likely feeds on plant leaves, flowers, buds, and roots.

Breeding. Unalaska Collared Lemmings might breed year-round. Gestation likely averages 20-21 days, with litters of 1-8 young.

Activity patterns. Unalaska Collared Lemmings probably actively feed day or night and throughout the year.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Because the Unalaska Collared Lemming is found on a single island, it could be considered as Endangered, but additional information on population status and threats is needed to determine if it is declining. Impacts of exotic rodent introductions such as the Brown Rat ( Rattus norvegicus ), the House Mouse ( Mus musculus ), and the Arctic Ground Squirrel ( Urocitellus parryi) are unknown. Furthermore, taxonomic status of many collared lemmings needs to be reviewed.

Bibliography. Bradley, Ammerman et al. (2014), Cook et al. (2010), Engstrom et al. (1993), Gilmore (1933), Linzey & NatureServe (Garibaldi & Hammerson) (2008), MacDonald & Cook (2009), Musser & Carleton (2005), Peterson (1967), Rausch (1977), Rausch & Rausch (1972), Stenseth & Ims (1993), Wilson & Ruff (1999).

Figures

34. Nearctic Collared Lemming (Dicrostonyx groenlandicus), 35. Ungava Collared Lemming (Dicrostonyx hudsonius), 36. Nelson's Collared Lemming (Dicrostonyx nelsoni), 37. Ogilvie Mountains Collared Lemming (Dicrostonyx nunatakensis), 38. Richardson’s Collared Lemming (Ducrostonyx richardsoni), 39. Palearctic Collared Lemming (Dicrostonyx torquatus), 40. Unalaska Collared Lemming (Dicrostonyx unalascensis), 41. Gray Red-backed Vole (Craseomys rufocanus), 42. Hokkaido Red-backed Vole (Craseomys rex), 43. Korean Red-backed Vole (Craseomys regulus), 44. Shanxi Red-backed Vole (Craseomys shanseius), 45. Anderson’s Red-backed Vole (Craseomys andersoni), 46. Smith’s Red-backed Vole (Craseomys smith), 47. Western Red-backed Vole (Myodes californicus), 48. Southern Red-backed Vole (Myodes gapperi), 49. Bank Vole (Mpyodes glareolus), 50. Tian Shan Red-backed Vole (Myodes centralis), 51. Large-eared Vole (Myodes macrotis), 52. Northern Red-backed Vole (Myodes rutilus), 53. Silver Mountain Vole (Alticola argentatus), 54. White-tailed Mountain Vole (Alticola albicauda), 55. Kashmir Mountain Vole (Alticola montosus), 56. Royle’s Mountain Vole (Alticola roylei), 57. Strelzov’s Mountain Vole (Alticola strelzouvi), 58. Tuva Mountain Vole (Alticola tuvinicus), 59. Gobi Altai Mountain Vole (Alticola barakshin), 60. null (null), 60. null (null), 61. Mongolian Mountain Vole (Alticola semicanus), 61. Mongolian Mountain Vole (Alticola semicanus), 62. Stoliczka’s Mountain Vole (Alticola stoliczkanus), 62. Stoliczka’s Mountain Vole (Alticola stoliczkanus), 63. Lemming Mountain Vole (Aschizomys lemminus), 63. Lemming Mountain Vole (Aschizomys lemminus), 64. Gansu Red-backed Vole (Caryomys eva), 64. Gansu Red-backed Vole (Caryomys eva), 65. Kolan Red-backed Vole (Caryomys inez), 65. Kolan Red-backed Vole (Caryomys inez), 66. Pere David's Red-backed Vole (Eothenomys melanogaster), 66. Pere David’s Red-backed Vole (Eothenomys melanogaster), 67. Yunnan Red-backed Vole (Eothenomys miletus), 68. Sichuan Red-backed Vole (Eothenomys chinensis), 69. Southwest China Red-backed Vole (Eothenomys custos), 70. Black-eared Red-backed Vole (Eothenomys olitor), 71. Yulongxuen Red-backed Vole (FEothenomys proditor), 72. Ward’s Red-backed Vole (Eothenomys wardi), 73. Hinton’s Red-backed Vole (Eothenomys hintoni), 74. Tarquinius Red-backed Vole (Eothenomys tarquinius), 75. Burrowing Vole (Hyperacrius fertilis), 76. Murree Vole (Hyperacrius wynnei)

Distribution. Unalaska I in Aleutian Is of Alaska.