Fig. 18. Probable geographic ranges of Sorex vagrans vagrans, its derivative subspecies, and S. v. mixtus.

1. S. v. vancouverensis
2. S. v. vagrans
3. S. v. halicoetes
4. S. v. paludivagus
5. S. v. obscuroides
6. S. v. mixtus

Remarks.—Restriction of the range of S. v. monticola to Arizona and New Mexico leaves shrews that were formerly assigned to this subspecies from Utah, Idaho, Washington and southern British Columbia unassigned. Several names are available for consideration. The name Sorex vagrans dobsoni Merriam, 1891, type locality Alturas Lake, Blaine Co., Idaho, was once applied to small shrews from Idaho, Montana, Wyoming, and Utah, but was considered by Jackson to be synonymous with S. v. monticola. The name Sorex vagrans amoenus Merriam, 1895, type locality near Mammoth, Mono Co., California, has been applied to wandering shrews from western Nevada, northeastern California and southern Oregon. Sorex vagrans nevadensis Merriam, 1895, type locality Reese River on Nye-Lander Co. line, Nevada was considered by Hall (1946:119) to be synonymous with S. v. amoenus. Specimens of Sorex vagrans west of the Cascade Mountains have long been referred to the nominate subspecies which has its type locality at Willapa Bay, Pacific Co., Washington. Over so wide an area it is only to be expected that some geographic variation is to be found. Thus specimens from central Nevada average slightly paler in summer pelage than those from the Pacific Coast or from the foothills of the Rocky Mountains. In addition there are slight average differences in size from place to place. Topotypes of S. v. vagrans, however, show a fair degree of variability and some are nearly as pale as the paler Great Basin stocks. Furthermore topotypical individuals of vagrans can be lost in series of S. v. amoenus, although amoenus is shorter-tailed on the average. Specimens from the western foot-hills of the Rocky Mountains show an amazing series of relationships with the montane S. v. obscurus. In Utah, as previously pointed out, complete intergradation occurs. At 1 mi. N Heath, Washington Co., Idaho, the lowland and the highland forms approach each other within a short distance and still maintain a degree of distinctness, especially in size. In northwestern Montana intergradation is extensive (Clothier, 1950). In northeastern Washington distinctly separable populations occur within a few miles of one another. In southern British Columbia some populations are clearly intergrades while at 6 mi. S Yahk intergradation seemingly has not taken place. Where some intergradation has occurred the result often has been increased size of the lowland shrews, although they usually retain the reddish summer pelage rather than acquiring the more grayish pelage of obscurus. The name dobsoni was based upon shrews from a place where lowland and highland forms occur almost together with only a slight amount of intergradation. Examples of "dobsoni" may not with certainty be distinguished from typical vagrans except that they are, as Merriam (1895:68-69) points out, somewhat larger. Merriam (loc. cit.) further notes that dobsoni is "intermediate in size and cranial characters between S. vagrans and obscurus;" a statement which hits very close to the heart of the matter. I consider the name dobsoni to apply to intergrades. To attempt to apply the name to the highly variable populations of intergrades from British Columbia to southern Idaho seems inadvisable. I have examined the possibility of using the name amoenus for the animals from this region. The characters which set amoenus apart from vagrans, slightly shorter tail and slightly darker summer pelage, however, are not universally found in shrews from the Columbian Plateau and eastern Great Basin and furthermore these differences between amoenus and vagrans do not seem to me to be of great enough magnitude to warrant subspecific recognition of the former. Thus the name S. v. vagrans may apply to shrews in the region under consideration. The subspecies, as thus thought of, embraces several incipient subspecies, namely (1) the populations on the isolated mountain ranges of Nevada, (2) the coastal rain forest population and possibly (3) the population on the Columbian Plateau.

In western British Columbia, Washington, and Oregon no evidences of intergradation between S. v. vagrans and the races setosus, permiliensis, bairdi, yaquinae, or pacificus are seen. In this region S. v. vagrans occurs sympatrically with one or the other of these subspecies. Different degrees of differentiation thus obtain between the subspecies vagrans as here defined and the surrounding subspecies of Sorex vagrans to wit: complete intergradation and allopatry in Utah with S. v. obscurus; partial intergradation and partial sympatry with S. v. obscurus in the foothill region from Idaho to British Columbia; no intergradation and complete sympatry with all the other races of Sorex vagrans from the Cascades to the coast and south to San Francisco Bay. The relationship of S. v. vagrans to the wandering shrews of the high Sierra is discussed on page 58.

Throughout most of the Great Basin and Columbian Plateau Sorex vagrans is, with the exception of the rare S. merriami and S. preblei, the only small shrew. In the Cascades and in the coastal lowlands it is the only small shrew except for S. cinereus and S. trigonirostris, both extremely rare and local in this region. S. vagrans seemingly competes to a certain extent with the larger S. trowbridgii in western Washington and seems to be partially dominant to trowbridgii, at least in marshy habitats (Dalquest, 1941:171).

Specimens examined.—Total number, 1197.

British Columbia: Osoyoos District: Okanagan, 20 PMBC; Okanagan Landing, 2 PMBC; Nahun Plateau, 2 PMBC. Vancouver District: Vancouver, 2 PMBC. New Westminister District: Port Moody, 16 BS; Westminster Jct., 4 AMNH; Langley, 1 BS; Vedder Crossing, 1 PMBC; Huntingdon, 69 NMC; Sumas, 16 BS; Cultus Lake, 1 NMC. Similkameen District: Princeton, 6 Mile Creek, 1 NMC. Hedley, Stirling Creek, 7 NMC; Fairview-Keremeos Summit, 5 NMC; Oliver, 1 NMC; Westbridge, 6 NMC; Osoyoos, 1 PMBC; Osoyoos-Bridesville Summit, 4 NMC; Cascade, 7 NMC. Nelson District: Kuskonook, 1 PMBC; Rossland, 14 NMC; Trail, 2 NMC; Creston, 4 PMBC, 4 NMC; near Creston, 7 NMC. Cranbrook District: Cranbrook, 5 BS; Yahk, 2 NMC; Yahk Camp 6, 2 NMC; Goatfell, 2 NMC. Fernie District: Newgate, 3 NMC.