Sorex portenkoi Stroganov 1956

70.

Portenko’s Shrew

Sorex portenkoi

French: Musaraigne de Portenko / German: Portenko-Rotzahnspitzmaus / Spanish: Musarana de Portenko

Taxonomy. Sorex portenkoi Stroganov, 1956,

Anadyr River, shore of Anadyr estuary, Chukchi Peninsula, Russia.

Evidence retrieved from karyotype com- position and mtDNA and nDNA sequenc- es classify S. portenkoi in the S. cinereus group and subgenus Ofisorex. Species in subgenus Otisorex mostly occur in North America. Palearctic species in subgenus Otisorex (S. camtschaticus, S. portenkoi, and S. leucogaster) are virtually identical in

mtDNA and nDNA structures. Sorex portenkoi is sometimes considered as a Palearctic subspecies of S. jacksoni. Monotypic.

Distribution. Endemic to Chukchi Peninsula, Russia.

Descriptive notes. Head-body 53-60 mm, tail 25-36 mm; weight 3-7 g (one specimen). Portenko’s Shrew is small. Tail is relatively short and rarely exceeds 50% of the head-body length. Pelage is tricolored, dark brown dorsum has distinct boundary with light brown sides, and venteris light gray. Chromosomal complement has 2n = 60 and FN = 62, with 29 pairs of acrocentric autosomes. X-chromosome is large submetacentric, and Y-chromosome is small submetacentric.

Habitat. Tundra zone in open tundra habitats of seashore valleys, dwarf Arctic birch stands,riverside willow shrubs, alder thickets, and dwarf pine stands. Portenko’s Shrew prefers well-developed moss cover, tussocks, and plant litter accumulations at water’s edge.

Food and Feeding. Adult and larval small insects and spiders were found in gastric contents of Portenko’s Shrews.

Breeding. One young-of-the-year female Portenko’s Shrew was captured on 3 September that had reproduced, and her breasts were reduced.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Portenko’s Shrew dominates the shrew community on the Chukotka Peninsula and is common throughoutits distribution, except in western periphery of the distribution.

Bibliography. Andreev et al. (2006), Demboski & Cook (2003), Dokuchaev (1997b), Ivanitskaya & Kozlovsky (1985), Stroganov (1957), Yudin (1989).