Sorex ugyunak

69.

Barren Ground Shrew

Sorex ugyunak

French: Musaraigne de Beaufort / German: Kanadische Tundraspitzmaus / Spanish: Musarafna de tierras aridas

Taxonomy. Sorex cinereus ugyunak R. M. An- derson & Rand, 1945,

“ Tuktuk (Tuktuyak- tok), northeast side of Mackenzie River delta, south of Toker Point, Mackenzie District, Northwest Territories, Canada.”

Sorex ugyunak is in the S. cinereus group and subgenus Otisorex. It is included in the Beringian clade along with S. pribilofensis, S. portenkor, S. jackson, S. camtschaticus, and S. leucogaster; all six species might repre-::: sent one wide-ranging species based on

genetic information, but they are retained as distinct here until additional research is undertaken. S. ugyunak has been included in S. cinereus, but genetic and morphological evidence supports its recognition as a distinct species. Monotypic.

Distribution. N Alaska (USA), N Yukon, N Northwest Territories, Nunavut, extreme NE Saskatchewan, and NW Manitoba (N Canada).

Descriptive notes. Head-body 47-70 mm, tail 32-37 mm, hindfoot 12-14 mm; weight 4-5 g. The Barren Ground Shrew is small to medium-sized, with striking pelage. Dorsum is dark brown—darker than in the Pribilof Island Shrew (S. pribilofensis) but lighter than in the Saint Lawrence Island Shrew (S. jacksoni); venter and lower sides are whitish with brownish tone; and distinctive line separates dorsum and sides. Tailis relatively short, narrow, and bicolored, being light brown above and whitish below, with brown or buffy tuft of hair at tip. Juvenile Barren Ground Shrews are more uniformly colored than adults. Teeth are dark red. There are five unicuspid,fifth is minute, and first through fourth get slightly smaller from front to back. Chromosomal complement has 2n = 60 and FN = 62.

Habitat. Moist tundra, with shrubby willows and birch, and sedge and grass meadows.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Barren Ground Shrew is widespread with no major threats and is considered relatively common throughout its distribution.

Bibliography. Cassola (2016t), Demboski & Cook (2003), Hope et al. (2012), Ivanitskaya & Kozlovsky (1985), van Zyll de Jong (1982, 1991).