California: Del Norte Co.: Smith River, 2 BS; Gasquet, 4 BS; Crescent City, 17 BS. Humboldt Co.: Orick, 13 BS; 1 mi. N Trinidad, 18 FC; Trinidad Head, 1 BS; Carson's Camp, Mad River, Humboldt Bay, 5 BS; Arcata, 3 BS; Cape Mendocino, 2 BS; 5 mi. S Dyerville, 1 BS. Mendocino Co.: Mendocino, 6 BS.
Marginal Records.—Oregon: Marshfield; Umpqua. California: Gasquet; 5 mi. S Dyerville; Mendocino, thence up coast to point of beginning.
Sorex vagrans yaquinae Jackson
Sorex yaquinae Jackson, Proc. Biol. Soc. Washington, 31:127, November 29, 1918.
Sorex pacificus yaquinae, V. Bailey, N. Amer. Fauna, 55:364, August 29, 1936.
Type.—Adult female, skin and skull; No. 73051 U. S. Biol. Surv. Coll., obtained on July 18, 1895, by B. J. Bretherton, from Yaquina Bay, Lincoln Co., Oregon.
Diagnosis.—Size large for the species; average and extreme external measurements of 11 specimens from Oakridge, Lane Co., Oregon, are: total length, 125.3 (11-136); tail, 55.1 (49-61); hind foot, 14.9 (14-16). Color reddish in summer, browner or grayer in winter.
Comparisons.—See account of S. v. pacificus for comparison with that subspecies. Larger and more reddish than S. v. bairdi with which it intergrades to the north and east. Much larger and more reddish than the sympatric S. v. vagrans.
Remarks.—The name yaquinae actually applies to a population of intergrades between pacificus and bairdi. There is much variation over the range of the subspecies, and individuals from the western and southern parts are larger than those from the west slope of the Cascades. Specimens from Vida and McKenzie Bridge are smaller than those from Mapleton, Mercer, and the type locality but still seem closer to yaquinae than to topotypes of bairdi. Between Marshfield and Umpqua on the one hand, and the Columbia River and the Cascade Mountains on the other, the size of Sorex vagrans decreases quite rapidly from the large pacificus to the smaller permiliensis. Size decreases less rapidly northward along the coast than it does eastward toward the mountains; consequently, at any given latitude, coastal shrews are larger than mountain shrews. In this area of rapid change in size it is difficult to draw subspecific boundaries between pacificus, yaquinae, and bairdi, and this must be done somewhat arbitrarily.
Jackson (1928:141) remarked upon the possibility that intergradation between pacificus and yaquinae took place. He noted also the close resemblance between yaquinae and bairdi, and stated (loc. cit.) that specific affinity between the two might be demonstrated with more specimens. He had a series of eight specimens from Vida, Oregon, seven of which he assigned to S. o. bairdi and one to yaquinae. I have examined these specimens and find no more variation between the largest and the smallest than would be expected in any normally variable series of shrews. Vernon Bailey (1936:364) arranged yaquinae as a subspecies of pacificus without giving his reasons for so doing.