84.

Fog Shrew

Sorex sonomae

French: Musaraigne de Sonoma / German: Nebelspitzmaus / Spanish: Musarana de Sonoma

Other common names: Sonoma Shrew

Taxonomy. Sorex pacificus sonomae H. H. T. Jackson, 1921,

“ Sonoma County side of Gualala River, Gualala, California,” USA.

Sorex sonomae is in the S. sonomae group along with S. pacificus and S. bairdi and sub- genus Otisorex. The S. sonomae group 1s sister to the S. monticolus group and includes northern populations of S. monticolus, sister to S. sonomae . Continued taxonomic revision is needed to resolve paraphyly of S. monticolus with respect to the S. sonomae

group and exact placement of S. sonomae, which is either sister to the S. palustris group and the Coastal S. monticolus + S. pacificus / S. bairdi clade, or closer to S. pacificus, S. bairdi, and the Coastal S. monticolus . Two subspecies recognized.

Subspecies and Distribution.

S.s.sonomaeH.H.T.Jackson,1921—WCOregonStoWCCalifornia(WUSA).

S. s. tenelliodus Carraway, 1990 — NW & SC Oregon (NW USA).

Descriptive notes. Head-body 67-89 mm, tail 49-68 mm, hindfoot 15-17 mm; weight 7-14 g. The Fog Shrew is large, very similar to the Pacific Shrew ( S. pacificus) and only distinguishable based on cranial and dental characteristics. Dorsum is rich reddish brown to dark brown, and venter is orangish brown,slightly paler than dorsum. Feet are pale brown. Tail is long, narrow, nearly naked, and slightly bicolored, being pale brown above and slightly lighter below. I' lack tines and have no median tines or protuberances (which is found in the Pacific Shrew). Teeth are pigmented dark reddish. There are five unicuspids, third is smaller than fourth, and fifth is minute.

Habitat. Generally moist wooded areas with dense ground cover, such as chaparral, coastal coniferous forests, and marshy regions.

Food and Feeding. Fog Shrews feed on various small invertebrates, such as insects, snails, slugs, earthworms, and centipedes; some plant and fungal material; and possibly small vertebrates.

Breeding. Pregnant Fog Shrews have been recorded in March-September in California, and litters apparently have 2-6 young.

Activity patterns. The Fog Shrew is probably similar to the Pacific Shrew.

Movements, Home range and Social organization. Fog Shrews are solitary.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Fog Shrew is widespread and has no major threats currently facing it, although little is known of its ecology. Additional research is needed.

Bibliography. Carraway (1985, 1988, 1990), Demboski & Cook (2001).