Wandering Shrew
The size of the wandering shrew varies from small in the subspecies monticola and vagrans to large in the subspecies pacificus. The tail makes up from a little more than a third to almost half of the total length. The color pattern ranges from tricolored through bicolored to almost monocolored. Color ranges from reddish (Sayal or Snuff Brown) to grayish in summer pelage and from black to light gray in winter. Diagnostic dental characters include: 3rd upper unicuspid smaller than 4th, and unicuspids, except 5th, with a pigmented ridge extending from near apex of each tooth medially to cingulum and sometimes ending as internal cusplet. S. vagrans differs from members of the ornatus group in less flattened skull, and in more ventrally situated foramen magnum that encroaches more on the basioccipital and less on the supraoccipital. The wandering shrew differs from S. trowbridgii and S. saussurei in the dental characters mentioned above. These dental characters also serve to distinguish S. vagrans readily from S. cinereus, S. merriami, and S. arcticus which may occur with vagrans. The large marsh shrew and water shrew, S. palustris and S. bendiri, can be distinguished at a glance from S. vagrans by larger size and darker color.
Fig. 15. Diagrammatic representation of the probable phylogeny of Sorex vagrans and its near relatives.
In the following treatment of the 29 subspecies of Sorex vagrans, the subspecies are arranged in geographic sequence, beginning with the southernmost large subspecies on the California coast and proceeding clockwise, north, east, south, and then west back to the starting point.
Sorex vagrans sonomae Jackson
Sorex pacificus sonomae Jackson, Jour. Mamm., 2:162, August 19, 1921.
Type.—Adult female, skin and skull; No. 19658, Mus. Vert. Zool.; obtained on July 2, 1913, by Alfred C. Shelton, from Gualala, on the Sonoma County side of the Gualala River, Sonoma Co., California.
Range.—Coastal California from Point Reyes north to Point Arena.