Part 68

Compared with that of M. f. washingtoni the skull of the male is shorter, especially in the preorbital region and is relatively broader across the mastoidal processes and zygomatic arches. The skull of the female is longer in the preorbital region, has a less cylindrical braincase and differs less from the male skull than is the case in M. f. washingtoni. Compared with M. f. effera, the skull of the male is smaller in every part measured and relative to the basilar length is broader across the mastoids and has relatively shorter tympanic bullae. From M. f. nevadensis the skull of the male differs in the same way except that size is about the same. The skull of the female oregonensis is more heavily ridged and is relatively broader across the mastoids than that of effera. From M. f. saturata, oregonensis is not surely known to differ in cranial characters. From M. f. munda, oregonensis differs in having the skull of both sexes smaller, and on the average, in all parts measured, has a less marked postorbital constriction, relatively narrower interorbital region and relatively more expanded zygomata. From M. f. altifrontalis, males of oregonensis differ on the average, in having larger teeth, and relative to the basilar length, a greater mastoid breadth and a shallower braincase as measured at the anterior margin of the basioccipital. Females of oregonensis differ in larger average size of skull, except for breadth of rostrum and interorbital breadth which, therefore, are relatively less in oregonensis, as also is the relative depth of the skull measured at the posterior borders of the upper molars and at the anterior margin of the basioccipital. However, skulls of females of oregonensis have relatively longer tooth-rows and are relatively broader across the zygomata and mastoidal processes.

Remarks.--In 1896, Merriam named oregonensis as a subspecies of the California bridled weasel on the basis of a single specimen taken by Clark P. Streator. Three additional specimens were acquired in later years, by workers of Dr. Merriam's bureau, from near the type locality and specimens from farther north in Oregon have been accumulated at the University of Oregon. The most satisfactory material is that saved from Humboldt County by the late H. E. Wilder, which, when brought together, is adequate to give some idea of the range of variation that can be expected in a given population.

Of two specimens from Goldbeach, one shows approach to altifrontalis in that the color of the underparts stops at the ankle, and in one, the angle of the mouth is dark colored. Specimens from Eugene and vicinity lack the white facial markings, and in this feature approach the adjoining washingtoni-effera-nevadensis stock. A specimen from 6 miles south of Medford shows approach to saturata in the interruption, on the ankle and lower tibial region, of the color of the underparts. One adult female, no. 1413, Univ. Oregon, from the Rogue River Valley, 13 miles southwest of Grants Pass, stands out prominently, among the other specimens from extreme southern Oregon and northwestern California, by reason of the near (18) Apricot Yellow color of the underparts, but this same color occurs in specimens from the more northerly localities of Buchanan, Eugene, Vida Fish Hatchery, and McKenzie Bridge, as well as in no. 2178, Univ. Oregon, from Cresent Lake. The last mentioned specimen is here referred to nevadensis.

Two females referred to oregonensis from southern Oregon differ so greatly in size of skull that they challenge one's imagination in any attempt to provide an explanation for so wide a range of variation in one subspecies. One of these, no. 244520, U. S. Nat. Mus., is an adult female from Medford. The other, no. 224034, U. S. Nat. Mus., is a subadult female (though labeled male) from 43 miles northeast of Grants Pass. The skull of the adult from Medford has a basilar length of 41.5, upper tooth-rows, 16.1 in length, and a weight of 2.75 grams, whereas corresponding figures for the subadult are only 33.8, 12.9, and 1.4. Two other adult females are intermediate in size: No. 1413, Univ. Oregon, from 13 miles southwest of Grants Pass, Oregon, approaches the specimen from Medford in size, and the second specimen, no. 34325, Mus. Vert. Zoöl., from Carlotta, California, is smaller.

Not only is there a difference in length between the skulls of the two extremes of the females but this difference extends to all other dimensions of their skulls, and is most pronounced in the preorbital region. The differences in breadth of the braincase and other parts of the skull are relatively less than the differences in length. Differences of the same nature, although of lesser degree than found in the females, are to be seen in two males. The skull of an adult no. 51590, Mus. Vert. Zoöl., from 6 miles south of Medford, has a basilar length of 46.4, upper tooth-rows, 17.6 mm. long, and a weight of 4.0 grams, whereas corresponding figures for the subadult type specimen from Grants Pass, are only 43.0, 16.2, and 3.3.

The wide range of variation in size of skull of both sexes, together with the considerable variation in color pattern of the specimens here referred to oregonensis raises the suspicion that we are using the name in a composite sense; nevertheless, to recognize more than one subspecies with the material now available would be unwise.

A subadult female, of abnormal color, no. 47149, Mus. Vert. Zoöl., taken by Mr. H. E. Wilder at Carlotta, California, on December 20, 1930, in a region where weasels do not turn white in winter, is white, except for the black tip of the tail, but has a suffusion of orange. This specimen, discussed at greater length on page 43, is instructive in that it suggests that there are separate determiners for the brown and red elements of the pelage. It is interesting also as suggesting how natural selection may tend to eliminate from the population a conspicuous color-variation of this kind. At any rate, Mr. Wilder (Ms.) states: "This specimen was picked up in a field, where it evidently had been dropped by a hawk or an owl." The braincase of the skull is crushed in three places as though by a raptor's beak. None of the several other weasels, all normally colored, saved by Mr. Wilder from this general locality gives evidence of having fallen a victim to a raptor.

Only 2 skulls of the 12 adults and subadults examined show malformation of the frontal sinuses such as results from the presence of parasites.

Specimens examined.--Total number, 29, arranged within states from north to south by counties. Unless otherwise indicated specimens are in the collection of the United States National Museum.

=California.= Del Norte County: Requa, 1. Humholdt County: Eureka, 2 (1, 1); Ferndale, 1; Fortuna, 2; Carlotta, 6 (3, 3); 12 mi. E Bridgeville, 1; 2 mi. W Bridgeville, 1.

=Oregon.= Washington County: Forest Grove, 1. Marion County: Salem, 2. Benton County: Buchanan, 1. Lane County: McKenzie Bridge, 1; Vida Fish Hatchery, 1; Eugene, 1. Douglas County: Anchor, 1. Curry County: Gold Beach, 2. Josephine County: Rogue River Valley (Grants Pass), 1; 13 mi. SW Grants Pass, 1. Jackson County: Medford, 2; 6 mi. S Medford, 1.

=Mustela frenata munda= (Bangs)

Long-tailed Weasel

Plates 1, 19, 20, 21, 22, 23, 30, 34, 35, 36 and 40

Putorius xanthogenys mundus Bangs, Proc. New England Zoöl. Club, 1:56, June 9, 1899; Stephens, California mammals, p. 247, 1906.

Mustela frenata, Audubon and Bachman, Journ. Acad. Nat. Sci. Philadelphia, 8 (Pt. 2):291, 1842 (North California about 40° latitude).

Mustela xanthogenys munda, Miller, U. S. Nat. Mus. Bull., 79:99, December 31, 1912.

Mustela frenata munda, Hall, Carnegie Instit. Washington Publ. 473:107, November 20, 1936.

Type.--Male, adult, skull, os penis and skin; no. 5459, collection of E. A. and O. Bangs, but now in collection of Mus. Comp. Zoöl.; Point Reyes, Marin County, California; June 19, 1896; obtained by C. A. Allen; original no. 931. (See comments under "Remarks," below, on places in California to which the name Point Reyes has been applied.)

The skull (pls. 19-21, 30) is complete and unbroken. I1 on each side and right I2 are broken away; p2 and p3 on each side have been aborted and the only alveoli remaining are two for the right p3. Otherwise all teeth are present and entire. The skin is fairly well made and in good condition.

Cranially, the type is a "runt"; its small size and the circumstance that the tympanic bulla is longer than the lower molar and premolar tooth-row and longer than the rostrum are features which differentiate the type from any other specimen seen of this race.

Range.--Sea level to at least 6,000 feet (South Yolla Bolly Mountain, Trinity County, California); Upper Sonoran and Transition life-zones of the coast and Coast Range of northwestern California from the Golden Gate northward into southern Humboldt and Trinity counties. See figures 29 and 30 on pages 221 and 314.

Characters for ready recognition.--Differs from M. f. oregonensis in longer hind foot of males which is more than 50 mm., and in both sexes, larger, more prominently ridged skull (see measurements and plates); from M. f. saturata by presence of nasofrontal white spot, larger and relatively shallower skull of males and larger skull of female; from M. f. nevadensis by presence of well-developed, white, facial markings; absence of color of underparts on ventral face of proximal third of tail; and hind foot of males more than 50; from M. f. xanthogenys by near (l) Sudan Brown to near (l) Antique Brown rather than Buckthorn Brown colors of upper parts and greater size, and in adult male basilar length more than 45 and hind foot more than 47; from M. f. nigriauris by having inside of ears same color as back rather than much darker than back.

Description.--Size.--Male: Three adults and two young from Point Arena and Gualala, Mendocino County, yield average and extreme measurements as follows: Total length, 447 (434-470); length of tail, 167 (150-185); length of hind foot, 53 (50-60). Corresponding measurements of three adults from 5 and 6 miles west of Inverness, Marin County, are: 430 (420-440), 154 (141-160), 48 (48-49). Corresponding measurements of four individuals (3 adults and 1 young of large size) from South Yolla Bolly Mountain, Trinity County, are: 383 (374-400), 134 (130-138); 44 (43-44). The tail averages 60 per cent as long as the head and body in the series from Point Arena, 56 per cent in the series from Point Reyes, and 53 per cent in the series from South Yolla Bolly Mountain. In every specimen except two, length of hind foot less than basal length. The two exceptions are no. 19720, M.V.Z., male adult from Point Arena in which the hind foot is recorded as 60 (probably an error in measurement), and no. 19721, M.V.Z., from the same place, in which the skull has not yet attained its full growth.

Female: One adult from Point Arena measures as follows: Total length, 383; length of tail, 134; length of hind foot, 43. Corresponding measurements of an adult from seven miles north of Laytonville, Mendocino County, are: 336, 121, 33 (= 36 on dried skin). Corresponding measurements of an adult from South Yolla Bolly Mountain, Trinity County, are, 326, 113, 37. In these three specimens, the tail is, in the order given, 54, 56, and 53 per cent as long as the head and body. Length of hind foot more than basal length.

Differences in external measurements of the two sexes as indicated by the five males and one female from Point Arena, are: Total length, 64; length of tail, 33; length of hind foot, 10. Weights of 2 adult males are 265 and 221 grams and of one adult female 155 grams.

Externals.--As described in Mustela frenata nigriauris.

Color.--Spot between eyes, narrow band or spot confluent with color of underparts on each side of head anterior to each ear, chin, lower lips, and rarely posterior third or less of each upper lip white; dark spot posterior to each angle of mouth uniformly present and of large size; tip of tail black; remainder of upper parts near (14 l) Sudan Brown and tone 4 of Raw Umber of Oberthür and Dauthenay, pl. 301; occasionally, slightly darker brown on forehead, nose, and about eyes. Underparts near (a to c) Ochraceous-Buff and sometimes Orange-Buff. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind limbs over antiplantar faces of toes. Least width of color of underparts averaging, in a series of 5 males from Mendocino County, 57 (46-67) per cent of greatest width of color of upper parts; 38 (35-40) in 3 males from Point Reyes, Marin County. Black tip of tail in Mendocino County series averaging 53 (46-60) mm., which is same length as hind foot and 32 per cent of length of tail. In Point Reyes males, black tip of tail averages 44 (34-52) mm., which is less than length of hind foot and 45 per cent as long as tail-vertebrae.