Part 17

For comparisons with Zapus princeps cinereus, Zapus princeps pacificus and Zapus princeps idahoensis see accounts of those subspecies.

Remarks.--The coloration in Z. p. oregonus varies somewhat from north to south. In the northern part of the range the average coloration of the upper parts is darker with more ochraceous on the sides. To the southward the upper parts are progressively paler and the sides are near Light Pinkish-Cinnamon. Because of this variation of color, and because of the small samples available to workers in the past, three populations of this subspecies have been named as distinct. However, with the large amount of additional material now available, the supposed diagnostic characters of these "forms" prove to be within the range of individual variations of each of several populations of which large samples are available.

Zapus major Preble (1899:24) was described as having zygomata short, palate broad and long, incisive foramina large and elliptical, and color dark. Some specimens of Z. p. oregonus, from nearly all parts of its geographic range, show these same characters. Resemblances in anteriorly divergent tooth-rows, broad interorbital region, small auditory bullae, and posteriorly narrow nasals, are additional reasons for placing Z. major as a synonym of Z. p. oregonus.

Zapus nevadensis Preble (1899:25), here considered a synonym of Z. p. oregonus, was described as having: auditory bullae small, posterior border of the palate usually convex anteriorly, palatal bridge long, and color pale. These characters, however, are within the range of individual variation of Zapus p. oregonus. Similarities such as tooth-rows diverging anteriorly, nasals narrow posteriorly, interorbital region broad, and incisive foramina enlarged posteriorly are added reasons for placing Z. nevadensis as a synonym of Z. p. oregonus.

Zapus princeps palatinus Hall (1931:8) was described as having: palatal bridge long, incisive foramina wide posteriorly, posterior border of palate straight or convex posteriorly, and color pale. These characteristics are to be found in some individuals in most populations of Z. p. oregonus. Additional well marked cranial similarities, such as small auditory bullae, broad interorbital region, and nasals narrow posteriorly offer additional evidence as to the close relationship of Z. p. palatinus and Z. p. oregonus. Hall (loc. cit.), with a small sample available to him for comparative purposes (14 specimens of Z. p. palatinus and 12 specimens of Z. p. nevadensis), was impressed by the condition of the palate in Z. p. palatinus and wrote: "the generally straight, or even posteriorly convex, posterior border of the palate seems to be unique among described forms of Zapus. The name palatinus is given in allusion to this structural feature." With more than 300 specimens of Z. p. oregonus available for study I find that a straight or posteriorly convex posterior border of the palate occurs in more than 50 per cent of the individuals examined. Specimens displaying this described palatal condition are known from all parts of the range of Z. p. oregonus, but do occur in a higher percentage of specimens in the area ascribed by Hall (loc. cit.) to the range of Z. p. palatinus.

Intergradation with Zapus princeps idahoensis and Zapus princeps cinereus is discussed in the accounts of those subspecies.

Specimens examined.--Total, 340, distributed as follows:

CALIFORNIA: Modoc Co.: Buck Creek R. S., 1 (CAS); Willow Ranch, 4 (CAS); Sugar Hill, 5000 ft., 1 (MVZ); Goose Lake Meadows, near Sugar Hill, 4 (MVZ); Parker Creek, Warner Mts., 5500 ft., 18 (MVZ); Dry Creek, Warner Mts., 4800 ft., 3 (MVZ) east face Warner Peak, Warner Mts., 8700 ft., 1 (MVZ); 5 mi. NW Eagle Peak, 7000 ft., 5 (MVZ); Lassen Creek, 1 (SDM); Happy Camp, 1 (CAS).

IDAHO: Boise Co.: Bald Mtn. R. S., Boise Nat'l Forest, 10 mi. S. Idaho City, 7400 ft., 2 (USBS). Elmore Co.: Trail Creek, Boise Nat'l Forest, 2 (USBS). Washington County: 1 mi. NE Heath, SW Slope Cuddy Mtn., 4000 ft., 20 (5 MVZ).

NEVADA: Elko County: 6 mi. SW Mountain City, Cobb Creek, 6500-6550 ft., 44 (MVZ); summit between heads of Copper and Coon creeks, Jarbidge Mts., 18 (9 MVZ); head of Ackler Creek, 6800 ft., 2: Steel Creek, 7000 ft., 11 (4 MVZ); summit of Secret Pass, 6200 ft., 8; south fork Long Creek, 7830 ft., 4; Harrison Pass R. S., Green Mtn., Canyon, 6050 ft., 12. Eureka County: 4 mi. S Tonkin, Denay Creek, Roberts Mt's, 1 (MVZ). Humboldt County: Martin Creek R. S., 1 (MVZ); 13 mi. N Paradise Valley, 6700 ft., 19 (MVZ). Lander County: Kingston R. S., 7500 ft., 4 (MVZ). Nye County: Wisconsin Creek, 7000 ft., 12 (MVZ). White Pine County: Willow Creek, 2 mi. S Elko County line, Ruby Mts., 6500 ft., 24 (2 MVZ).

OREGON: Baker Co.: East Pine Creek, 2-1/2 mi. NE Cornucopia, 6 (USBS); McEwen, 2 (USBS); Bourne, 7 (USBS). Clackamas County: Marks Creek, 12 mi. N of Howard, 2 (USBS); Howard, 2 (USBS). Crook County: Ochoco R. S., 4000 ft., 4 (MVZ). Grant Co.: Austin, 2 (USBS); Cold Spring, 4900 ft., 8 mi. E Austin, 4 (MVZ); Beech Creek, 1 (USBS); Strawberry Mts., 6 (USBS); north fork Malheur River, 21 mi. SE Prairie City, 5000 ft., 21 (MVZ). Harney Co.: 10 mi. N. Harney, 1 (USBS); Steen Mts., Keiger Gorge, 6900 ft., 6 (USBS); Diamond, 4300 ft., 2 (USBS). Jefferson Co.: Foley Creek, 12 mi. E Hay Creek, 1 (USBS). Klamath Co.: Fort Klamath, 1 (USBS). Lake Co.: Silver Creek, 7000 ft., Yamsey Mts., 1 (USBS); 2 mi. E Lakeview, 5200 ft., 3 (MVZ). Malheur Co.: Jordan Valley, 4200 ft., 1 (USBS). Umatilla Co.: Meacham, 1 (USBS). Union County: Elgin, 2 (USBS). Wallowa Co.: Paradise, 10 mi. N Horse Creek, 7000 ft., 1 (USBS); Minam Lake, 1 (USBS); 16 mi. S and 3 mi. E Lostine, 5500 ft., 9 (MVZ); west fork Wallowa River, 5000 ft., 2-1/2 mi. above Wallowa Lake, 1 (FM); near Wallowa Lake, 4500 ft., 3 (FM). Wheeler County: 11 mi. W and 7 mi. S Mitchell, 4850 ft., 20 (MVZ).

WASHINGTON: Asotin Co.: Anatone, 3300 ft., 1 (USBS). Columbia County: Twin Buttes, 25 mi. SE Dayton, Blue Mts., 2 (MVZ); Stayawhile Spring, 5150 ft., 4 (MVZ).

Marginal records.--Washington: Anatone, 3300 ft. Oregon: East Pine Creek, 2-1/2 mi. NE Cornucopia. Idaho: 1 mi. NE Heath, SW slope Cuddy Mtn., 4000 ft.; Bald Mtn., R. S., Boise Nat'l Forest, 10 mi. S. Idaho City, 7400 ft.; Trail Creek, Boise Nat'l Forest. Nevada: Harrison Pass R. S., Ruby Mts.; Steel Creek, 7000 ft.; Wisconsin Creek, 7000 ft.; 13 mi. N Paradise Valley, 6700 ft. California: Lassen Creek; Buck Creek R. S. Oregon: Fort Klamath; Howard; Meacham. Washington: Twin Buttes, 25 mi. SE Dayton, Blue Mts.

=Zapus princeps pacificus= Merriam

Zapus pacificus Merriam, Proc. Biol. Soc. Washington, 11:104, April 26, 1897; Preble, N. Amer. Fauna, 15:30, August 8, 1899.

Jaculus hudsonius, Baird, Repts. Expl. and Surv. 111 8 (pt. 1):433, July 14, 1858 (part--the part from Canoe Creek, California).

Zapus alleni Elliot, Field Columbian Mus., publ. 27, zool. ser., 1:212, April 19, 1898, type from Pyramid Peak, Lake Tahoe, El Dorado County, California.

Zapus trinotatus alleni, Elliot, Field Columbian Mus. Publ. 91, zool. ser., 3:315, July 5, 1904; Preble, N. Amer. Fauna, 15:27, August 8, 1899.

Zapus pacificus alleni, Howell, Univ. California Publ. Zool., 21:232, May 20, 1920.

Zapus trinotatus pacificus, Bailey, N. Amer. Fauna, 55:233, August 29, 1936.

Zapus princeps alleni, Hall, Mammals of Nevada; Univ. California Press, Berkeley, California, 579, July 1, 1946.

Type.--Male, subadult, skin and skull, No. 80445, U. S. Nat. Mus. Biol. Surv. Coll.; Prospect, Rogue River Valley, Jackson Co., Oregon; obtained on August 29, 1896, by Edward A. Preble, original No. 1454.

Range.--Sierra Nevada Mt's, from Kern Peak, Tulare County, California, northeastward to Mt. Rose, Washoe County, Nevada, then northwestward through the Trinity and Salmon mountains, California, to the upper Rogue River Valley, Oregon, thence southwestward to South Yolla Bolly Mt'n, Tehama County, California. See fig. 46. Zonal range: Transition, Canadian, and Hudsonian.

Description.--Size medium; color bright; back near Ochraceous-Buff with admixture of black hair forming dark dorsal band; sides bright Ochraceous-Buff with fine admixture of black hair; lateral line blending with color of sides or wanting or indistinct; ventral surface white; tail bicolored, grayish-brown above, yellowish-white below, in some specimens with white tip; feet grayish-white above; ears dark, edged with Ochraceous Buff; braincase relatively narrow; incisive foramina relatively short; pterygoid fossae usually broad; proximal part of inferior ramus of zygomatic process of maxillary broad; postpalatal notch usually broadly rounded; auditory bullae relatively small and flattened; nasals parallel sided; maxillary tooth-row short; interorbital region moderately broad.

Comparison.--From Zapus princeps oregonus, Z. p. pacificus differs in being brighter in all pigmented areas; more ochraceous and less yellow laterally; dorsally more ochraceous and less black; size averaging smaller; maxillary tooth-rows shorter; auditory bullae less inflated and smaller; interorbital region averaging narrower; palatal bridge averaging shorter; incisive foramina shorter and posteriorly narrower; nasals parallel rather than narrowed posteriorly.

Remarks.--Original describers considered both Z. pacificus and Z. alleni as specifically distinct from Z. trinotatus. Merriam (1897a:104) named Z. pacificus and gave the following diagnostic characters: short rostrum and nasals; small auditory bullae; basioccipital broad between bullae. Elliot (1898:212) named Z. alleni and ascribed to it the following diagnostic characters: cranium long and narrow; nasals same breadth for entire length; palate wide; pterygoid fossae wide posteriorly; auditory bullae small; basisphenoid and basioccipital wide; upper tooth-rows short. Preble (1899:27) considered Z. alleni to be a subspecies of the species Z. trinotatus, remarking that the skulls are similar to those of Z. trinotatus but smaller with much smaller bullae; in coloration the animals are lighter above and without fulvous below. Preble remarked that the skull of Z. alleni differs so greatly from that of Z. montanus that comparison was not required. Preble (op. cit.:30) treated Z. pacificus as a full species. Howell (1920:233) considered Z. pacificus and Z. alleni to be subspecies of Z. pacificus. Howell (loc. cit.) pointed out size, cranial, and color similarities between the two, and remarked that pacificus is clearly distinct from Z. montanus, its nearest geographic neighbor. Hall (1946:578) arranged Z. alleni as a subspecies of Z. princeps, although not on grounds wholly satisfactory to him because actual intergrades between alleni and neighboring races of princeps were not available.

I here consider Z. alleni to be synonymous with Z. pacificus; the latter is a subspecies of Z. princeps. Certain diagnostic characters, such as the shape and size of the os penis, the diameter and pigment pattern of the hair, the over-all proportions of the skull, and the size and shape of the teeth indicate that alleni and princeps belong to the same species, even though animals from intermediate geographic areas are not available to show actual intergradation.

The diagnostic characters referred to in the original description of Z. alleni, as given earlier in this account, agree with characters of specimens of Z. p. pacificus. Howell (1920:233) remarks that, in coloration and length of foot, typical alleni differs but slightly from pacificus. Howell (loc. cit.) noted, as I also have, that there are slight cranial differences in specimens from various parts of the range of Z. p. pacificus; these variations are somewhat clinal in nature, cranial dimensions showing a slight increase from south to north. The largest animals occur in western Tehama, Trinity, and Siskiyou counties, California. Samples from various localities in Jackson County, Oregon, are slightly smaller than these, but are larger than specimens from the southern Sierra Nevada.