wunder · Library

Part 66

American Weasels · E. Raymond Hall — chapter 66 of 157 · ~2,022 words · public domain

Read in the Wunder reader — free

On May 5, 1933, Mr. Clark P. Streator, informed the writer that he remembered taking the type specimen of Mustela frenata saturata (Merriam) in the town of Siskiyou, Oregon. The exact place, he said, was reached, at the time of his work there, by going one or two blocks east of the depot, then through a garden into the thick woods where there were springs and numerous burrows of the rodent, Aplodontia. Two other weasels labeled as taken at Siskiyou, on September 28 and 29, 1893, by Mr. Streator, are much lighter colored than the type of saturata and have the color of the underparts extended distally on the hind legs to the tips of the toes and in other features of coloration are more like nevadensis, the subspecies to which they are referred, than saturata. Probably these did not come from exactly the same place that the type specimen of saturata did. Although Mr. Streator does not remember the taking of these particular specimens in 1893, he does remember that on this visit to Siskiyou, he walked southward through the railroad tunnel and collected on the opposite side of the ridge from Siskiyou. Here on more southern exposures, the country was markedly different than in the thick forest at Siskiyou. Probably these two specimens taken in 1893, and referred to nevadensis, came from a little way south of Siskiyou and from a different habitat and life-zone than the type specimen of M. f. saturata.

Of the 6 specimens examined, only one, the type, shows malformation of the frontal sinuses such as result from infestation by parasites.

Specimens examined.--Total number, 6, as follows:

=California.= Siskiyou County: Jackson Lake, 5900 ft., 2, Mus. Vert. Zoöl. Humboldt County: South Fork Mt., 5500 ft., 1, Mus. Vert. Zoöl. County in question, Trinity Mts., summit east of Hoopa, 5800 ft., 1, U. S. Nat. Mus.

=Oregon.= Jackson County: Mt. Ashland, 1, Univ. Oreg.; Siskiyou, 1, U. S. Nat. Mus.

=Mustela frenata altifrontalis= Hall

Long-tailed Weasel

Plates 1, 19, 20, 21, 34, 35 and 36

Mustela frenata altifrontalis Hall, Carnegie Instit. Washington Publ. 473:94, November 20, 1936.

Putorius (Gale) brasiliensis frenatus, Coues, Fur-bearing animals, p. 142, 1877 (part).

Putorius saturatus Merriam, N. Amer. Fauna, 11:21, June 30, 1896 (part).

Mustela saturata, Miller, U. S. Nat. Mus. Bull., 79:98, December 31, 1912.

Type.--Male, adult, skull and skin; no. 42093, Mus. Vert. Zoöl.; Tillamook, Tillamook County, Oregon; July 10, 1928; obtained by Alex Walker; original no. 717.

The skull is complete and unbroken. P3 on the left side is missing; otherwise the teeth all are present and entire. The skin is well made and the enlarged scrotal pouch shows the collector's sexing of the specimen to have been correct.

Range.--Altitudinally from sea level up to at least 4800 feet (Mount Baker) in the Transition Life-zone of the humid, coastal region of Oregon, Washington and extreme southwestern British Columbia. See figure 29 on page 221.

Characters for ready recognition.--Differs from M. f. nevadensis in tone 4 of Brownish Drab, pl. 302, rather than tones 1-3, of Raw Umber, pl. 301, of Oberthür and Dauthenay of upper parts, in near (14 a´ to 16 c´) Ochraceous-Buff rather than Buff-Yellow to Straw Yellow of underparts, in that least width of color of underparts amounts to less than 37 per cent of greatest width of color of upper parts, in absence of color of underparts on ventral side of tail and on hind leg distal to knee, and in greater depth of skull through frontal region; from M. f. washingtoni in darker color of upper parts and underparts, latter near (14 a´ to 16 c´) Ochraceous-Buff rather than ranging from Buff-Yellow to Naples Yellow, in deeper skull in both sexes (see measurements), in males a shorter preorbital region, broader skull with longer bullae and in females a larger skull with interorbital breadth averaging more than 24 per cent of basilar length; from M. f. oregonensis in frontonasal white patch absent, color above darker (tone 4 of Brownish Drab, pl. 302, rather than tone 2 to 3 of Raw Umber, pl. 301 of Oberthür and Dauthenay), light-colored underparts narrower and not extended distally beyond knee, in females tooth-row shorter, amounting to less than 38 per cent of basilar length.

Description.--Size.--Male: Eight adult topotypes yield average and extreme measurements as follows: Total length, 426 (392-445); length of tail, 160 (148-170); length of hind foot, 47 (42-53). Tail averages 60 per cent as long as head and body. Length of hind foot averages more than basal length.

Female: Five adults from Tillamook and Blaine, Oregon, yield average and extreme measurements as follows: Total length, 347 (320-370); length of tail, 125 (114-131); length of hind foot, 38 (35-44). Tail averages 56 per cent as long as head and body. Length of hind foot less than basal length.

The average differences in the external measurements are: Total length, 79; length of tail, 35; length of hind foot, 9.

Externals.--Longest facial vibrissae black, brown or white (often all three colors in same specimen) and extending beyond ear; carpal vibrissae same color as underparts and extending to or beyond apical pad of fifth digit; hairiness of foot-soles (in summer pledge) slightly less than shown in figure 19.

Color.--Upper parts, in summer, near (n) Argus Brown or tone 4 of Brownish Drab of Oberthür and Dauthenay, pl. 302. Dark spot at each angle of mouth well developed; often fused with color of upper parts which sometimes covers lower lips. Chin white. Remainder of underparts near (14 a´ to 16 c´) Ochraceous-Buff. In winter, upper parts near (14) Argus Brown with smoked effect and Warm Buff to Naples Yellow below. Tip of tail at all times black. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and usually all of wrists, on medial side of hind legs typically only to knee but sometimes to ankle. Tips of toes of hind feet almost always marked with color of underparts. Least width of color of underparts averaging in a series of 14 males from Blaine, Oregon, 23 (14-36) per cent of greatest width of color of upper parts. Black tip of tail in 8 adult males from Blaine, Oregon, averaging 59 (47-70) mm. long; thus longer than hind foot and averaging 37 per cent of length of tail-vertebrae.

Skull and teeth.--Male (based on 9 adults from Blaine, Tillamook Co., Oregon): See measurements and plates 19-21; weight, 4.4 (3.3-5.3) grams; basilar length, 45.6 (42.4-47.7); zygomatic breadth more or less (usually more) than distance between condylar foramen and M1 or than between anterior palatine foramen and anterior margin of tympanic bulla; mastoid breadth more or less (usually more) than postpalatal length; postorbital breadth less (except in some instances of malformations of frontal sinuses which result from infestation by parasites) than length of upper premolars and more or less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth more or less than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; least width of palate more or less than length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 to 4 (including I3) upper incisors; height of tympanic bulla more than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and more or less than orbitonasal length; anterior margin of masseteric fossa directly below m2.

Female (based on 4 adults): See measurements and plates 34-36; weight, 2.2 (2.2-2.3) grams; basilar length, 38.1 (37.8-39.7); zygomatic breadth more or less (less in three of four specimens) than distance between condylar foramen and M1 or than between anterior palatine foramen and anterior margin of tympanic bulla; relation of postorbital breadth to other measurements in doubt because of malformation of frontal sinuses by parasites; least width of palate not less than greatest length of P4; tympanic bulla as far posterior to foramen ovale as width of 3-1/2 to 5-1/2 upper incisors; height of tympanic bulla more than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer or shorter than rostrum.

Compared with the skull of M. f. washingtoni that of each sex of altifrontalis averages slightly larger in every measurement taken, except measurements of teeth which are approximately the same, and is relatively deeper through the frontal region and through the braincase as measured at the anterior margin of the basioccipital. Skulls of females of altifrontalis have a relatively broader interorbital region. Skulls of males of altifrontalis further differ in having relatively, as well as actually, longer tympanic bullae, relatively lesser orbitonasal length and a greater relative breadth across the mastoids and across zygomata. Compared with M. f. nevadensis, the skull of the male of altifrontalis averages slightly larger and heavier although the skulls of females are of approximately the same size and weight. Relative to the basilar length, the skulls of both sexes are deeper through the braincase and narrower across the mastoids; the rostrum is broader, especially in males; the tooth-rows are shorter and the interorbital breadth less, especially in females. Comparison with the skull of oregonensis is made in the account of that subspecies.

Remarks.--Until the present study was begun, animals of this race have gone under the name Mustela saturata (Merriam). The United States National Museum has a juvenile taken, in 1858, by Wayne at Astoria, O. T.; the Samuel N. Rhoads collection contained one specimen taken in 1891, at Tacoma, Washington; one in the Bangs' collection was taken at Chilliwack, British Columbia, in 1895, and the Field Museum has one taken on the Olympic Peninsula in 1898. The best material is that collected by Alex Walker, at Tillamook, Oregon.

Intergradation with nevadensis is indicated by several specimens. The coloration of the one adult female, no. 90, Chas. R. Conner Mus., from Swamp Creek, Washington, has the color of the underparts extended down the hind legs over the feet, and over the proximal third of the ventral face of the tail as in nevadensis although the other two specimens from the same place have the color pattern of altifrontalis. Of the four specimens from British Columbia referred to this subspecies, only the specimen from Chilliwack is typical as regards color pattern. The one from Cultus Lake has the color pattern of nevadensis and might be referred to that race almost as well as to altifrontalis. The two specimens from Lihumption Park are intermediate between the two races in tone of color. Neither has the color of the underparts extended onto the tail or continuously over the hind feet as in nevadensis but each does have the color of the underparts less restricted and of lighter hue than in altifrontalis. Only one of the specimens, no. 7848 Canad. Nat. Mus., from Lihumption Park is adult and it has a skull which agrees with that of altifrontalis rather than nevadensis.

After writing the above, a good representation of the weasel population along the eastern side of Puget Sound was made available by friends in that area. Study of the weasels from there shows that their color is intermediate between that of altifrontalis and nevadensis. On the whole, they (specimens from Bellingham, for example) resemble one subspecies about as much as the other. In cranial characters some specimens, in certain features, approach nevadensis but most specimens agree with altifrontalis and all are more nearly like altifrontalis to which race all are referred.

The color of these animals is to me indistinguishable from that of washingtoni. The color of washingtoni is merely intermediate between that of nevadensis and altifrontalis. Nevertheless, the race washingtoni has cranial characters (long narrow skull) which set it off from both altifrontalis and nevadensis. This shape of skull is not found in the specimens from along the eastern side of Puget Sound; these animals have skulls like that of altifrontalis and when departures from this occur they are in the direction of nevadensis and not washingtoni.

← Previous chapterAll chaptersNext chapter →

American Weasels · The Wunder Library — complete classics, free to read, with narration.

© 2026 Wunder Learning LLC · Terms & Privacy