67.

Prairie Shrew

Sorex haydeni

French: Musaraigne des steppes / German: Prariespitzmaus / Spanish: Musarana de pradera

Other common names: Hayden's Shrew

Taxonomy. Sorex hayden: Baird, 1858,

“ Fort Union, Nebraska [later Fort Buford, now Mondak, Montana, near Buford, Williams Co., North Dakota],” USA.

Sorex haydeni is in the S. cinereus group and subgenus Otisorex. It is closest to the southwestern population of S. cinereus (which might represent S. haydeni), together sister

to the Beringian clade. Specific status of S. haydeni has recently been questioned because there is evidence of introgression between it and S. cinereus in Minnesota, but genetic data support it as a distinct species. Monotypic.

Distribution. SC Canada (C & S Saskatchewan and S Manitoba) and NC USA (from NE Montana, North Dakota, and NW Minnesota S to N Kansas, N Missouri, and W Mlinois).

Descriptive notes. Head—body 47-67 mm,tail 30-41 mm, hindfoot 10-12 mm; weight 2-5 g. The Prairie Shrew is small to medium in size, with brown dorsum,slightly paler sides, and whitish venter that is occasionally washed with yellow. Feet are pale. Tail is relatively short, narrow, and clearly bicolored, being brown above and whiter below; tail is tipped with brown hair tuft unlike in the Masked Shrew (S. cinereus) that has black tuft. Teeth are dark red. There are five unicuspids, fifth is minute, and first through fourth get slightly smaller from front to back. Chromosomal complement has 2n = 64 and FN = 66.

Habitat. Most commonly wet prairies and grasslands. The Prairie Shrew has been recorded occasionally in dry conifer forests but generally does not leave open grassland habitats.

Food and Feeding. Prairie Shrews primarily eat small soft-bodied invertebrates.

Breeding. Litters of Prairie Shrews apparently have 4-10 young.

Activity patterns. Prairie Shrews are probably active day and night, with more activity at night. They apparently make bulbous birdlike nests under logs and rocks.

Movements, Home range and Social organization. The Prairie Shrew is probably most similar to the Masked Shrew, but few specific studies have been conducted.

Status and Conservation. Classified as Least Concern on The IUCN Red List. There are no major threats to the wide-ranging Prairie Shrew, but additional research is needed. Fossils have been recorded from Moonshiner and Middle Butte caves in Idaho.

Bibliography. Banfield (1974), Bee et al. (1981), Brunet et al. (2002), Demboski & Cook (2003), Frey & Moore (1990), Hope et al. (2012), Junge & Hoffmann (1981), Mullican & Carraway (1990), Stewart et al. (1993), Volobouev & van Zyll de Jong (1994).