that color sometimes brown in winter (with more smoky tinge than
summer coat); upper parts ranging from tone 2 through tones 3 and
4 of Dark Chocolate (pl. 342) into tone 4 of Chocolate (pl. 343)
of Oberthür and Dauthenay; underparts (always white in winter) in
summer Sulphur Yellow or more whitish; least width of color of
underparts averaging, in 5 males from Mount Rainier, 31 (18-45)
per cent of greatest width of color of upper parts. Black tip of
tail, in same series, averaging 34 (29-40) mm., which is 45
(41-50) per cent of length of tail-vertebrae.
_Skull._--Male (based on 2 ad. and 13 sad.): See measurements and
plates 5-7. As described in _Mustela erminea richardsonii_ except
that: Weight, 1.0 (0.95-1.16) grams; basilar length, 32.3
(30.9-33.4); length of tooth-rows more or less than (about equal
to) length of tympanic bulla.
Female (illustrated by 5 adults): See measurements and plates
12-14. As described in _Mustela erminea richardsonii_ except that:
Weight, 0.59 (0.53-0.65) grams; basilar length, 28.1 (27.8-28.4);
breadth of rostrum ordinarily more than 30 per cent of basilar
length.
In comparison with _streatori_, skulls of males and females average
smaller in every cranial measurement taken. Teeth of about same size
and males 9 per cent, and females 8 per cent, lighter. In relation to
basilar length, skull of female shallower, tympanic bullae slightly
shorter and, on the average, zygomata less expanded.
In comparison with _muricus_, males average larger in every measurement
taken; 23 per cent heavier; in relation to other dimensions, braincase
shallower at anterior end of basioccipital. Females are of about equal
size; in relation to other dimensions, braincase shallower and mastoid
and zygomatic breadths less.
Comparisons with _invicta_ and _fallenda_ have been made in the
accounts of those subspecies.
_Remarks._--This is not a strongly marked race and in most of the
characters used for differentiating it from other races it resembles
either _streatori_ to the west or _muricus_ to the southeast.
Nevertheless, there is a geographic area, the southern Cascades of
Washington, throughout which individual characters are combined in
essentially the same way and there are a few features, for instance,
smaller skull of the female, in which _gulosa_ differs from either of
its close relatives. In view of these circumstances and because the
animals can not well be included in the subspecies _streatori_ or
_muricus_, _gulosa_ is recognized as distinct. The races _gulosa_ and
_olympica_ are what might be termed weakly differentiated subspecies in
contrast to the strongly differentiated subspecies _streatori_ and
_muricus_.
Of the 21 specimens in winter pelage, 17 are white and four are brown.
The brown winter coat is distinctly paler, with more of a smoky tinge,
than the brown summer pelage. The light-colored underparts are narrower
than in the subspecies immediately to the east but are wider than in
the coastal forms to the west. The dark color of the upper parts
extends onto the chest in front of the forelegs, as in the coastal
forms, in only one of the 13 specimens in summer pelage and in it on
one side only. The black tip of the tail is short as in the coastal
forms. One specimen is in transitional pelage. It has acquired
approximately half of the white winter pelage and was taken on October
12, 1897, at Keechelus Lake.
_Specimens examined._--Total number, 38, arranged by counties from
north to south. Unless otherwise indicated, specimens are in the
U. S. National Museum.
=Washington.= _King County_: 2 mi. E Skykomish, 2[51]. _Kittitas
County_: Keechelus Lake, 3 (1[1]); Martin, 1[1]; Easton, 3.
_Pierce County_: James Lake, 4370 ft., Mt. Rainier, 1; Glacier
Basin, 5935 ft., Mt. Rainier, 1; Meslers Ranch, 2000 ft., 1 mi. W
Rainier Park, 1. _Lewis County_: Mt. Rainier Nat'l Park, 5 (1 each
from: Paradise Park, 5400 ft.; Reflection Lakes, 4900 ft.;
Ohanapecosh [Hot] Springs, 2000 ft.; Tahoma Creek, 1[72]; Bear
Prairie); also in Mt. Rainier Nat'l Park, Longmire, 3 (1[72],
1[94]). _Skamania County_: Mt. St. Helens, 6000 ft., 1. _Klickitat
County_: Trout Lake, 18.
=Mustela erminea muricus= (Bangs)
Ermine
Plates 7, 8, 12, 13, 14 and 41
_Putorius (Arctogale) muricus_ Bangs, Proc. New England Zoöl. Club,
1:71, July 31, 1899.
_Putorius streatori leptus_ Merriam, Proc. Biol. Soc. Washington,
16:76, May 29, 1903. Type from Silverton, San Juan County,
Colorado.
_Putorius muricus_, Stephens, California Mammals, p. 248, 1906.
_Putorius cicognani_, Taylor, Univ. California Publ. Zoöl., 7:298,
June 24, 1911.
_Mustela streatori leptus_, Miller, U. S. Nat. Mus. Bull., 79:96,
December 31, 1912; Bailey, N. Amer. Fauna, 35:48, September 5,
1913; Dixon, Journ. Mamm., 12:72, February 12, 1931; Whitlow and
Hall, Univ. California Publ. Zoöl., 40:246, September 30, 1933.
_Mustela muricus_, Miller, U. S. Nat. Mus. Bull., 79:96, December
31, 1912; Kellogg, Univ. California Publ. Zoöl., 12:358, January
27, 1916.
_Mustela cicognanii lepta_, Dice, Journ. Mamm., 1:12, November 28,
1919; Hall, Mamm. Nevada, p. 184, July 1, 1946.
_Mustela rixosa_, Seton, Journ. Mamm., 14:70, February 14, 1933.
_Mustela cicognanii leptus_, Miller, Journ. Mamm., 14:368, November
13, 1933; Bailey, N. Amer. Fauna, 55:293, August 29, 1936.
_Mustela erminea murica_, Hall, Journ. Mamm., 26:84, February 27,
1945; Hall, Journ. Mamm., 26:181, July 19, 1945.
_Type._--Male, young, skull and skin; no. 9146, collection of E.
A. and O. Bangs in Mus. Comp. Zoöl.; Echo, 7500 ft., El Dorado
County, California; July 15, 1897; obtained by W. W. Price and E.
M. Nutting.
The skull has a fracture along the sagittal suture and fractures
on the left side of the braincase but these have been glued, and
no part of the skull is missing except in the region of the right
P4 which part has been shot away. On the left side m2 never
developed. Excepting this tooth and the right P4, all the teeth
are present and entire. The skin is well made but has the soles of
the hind feet turned up.
_Range._--Near 5300 feet (Denver) to 11000 feet (Santa Fe Baldy);
typically boreal but taken in Upper Sonoran Life-zone in winter at
Denver; from central and southwestern Montana, southern Idaho, and
Blue Mountains of southeastern Washington southward east of the
Cascade Divide through the Salmon River Mountains and Sierra
Nevada at least into Fresno County of California, in the Great
Basin to central Nevada, in the Rocky Mountains into northern New
Mexico; eastward to the Black Hills. See figure 25 on page 95.
_Characters for ready recognition._--Differs from _M. e. invicta_
by hind foot less than 36 and basilar length less than 35 in males
and by hind foot less than 29.5 and basilar length less than 30.5
in females; from _M. e. gulosa_, in both sexes, by upper parts
lighter, tone 2 of Chocolate or lighter (see description of
color), least width of light-colored underparts averaging about
two-thirds instead of one-third of greatest width of dark-colored
upper parts, in males, on the average, tail less than 65, weight
of skull less than 0.90 grams, basilar length less than 30.8
grams; from _M. e. streatori_, in both sexes, by upper lips white
(not brown), light color of underparts extending down hind leg
below knee, depth of skull at posterior border of upper molars
less than 7.7 in females and ordinarily less than 9.6 in males,
tail less than 62 in males and less than 49 in females.
_Description._--_Size._--Male: An adult from Black Butte,
California, measures: Total length, 227; length of tail, 55;
length of hind foot, 27. Corresponding measurements of another
from Wheeler Peak, Nevada, are: 220, 56, 26. Two subadults from
Colorado, one from Crested Butte and another from Coventry,
measure, respectively, as follows: 238, 227; 66, 60; 30, 30. An
adult from Wheeler Peak, Nevada, weighs 57.7 grams and another
from 2 mi. W Black Butte, Calif., 54.5 grams.
Female: Two adults from Teton County, Wyoming, measure: Total
length, 205, 200; length of tail 52,--; length of hind foot, 23,
23.7. A subadult from 9-1/2 mi. E Pocatello, Idaho, measures: 197,
50, 25. An adult from Wheeler Peak, Nevada, has corresponding
measurements of 190, 42, 23, and weighs 33.8 grams.
_Color._--As described in _Mustela erminea richardsonii_ except
that upper parts tone 2 or lighter of Chocolate of plate 343 of
Oberthür and Dauthenay; underparts white, Pale Buff or with faint
wash of Sulphur Yellow; least width of color of underparts in male
from Black Butte and one from Wheeler Peak, amounting to 65 and 59
per cent of greatest width of color of upper parts. Black tip of
tail, respectively, 28 and 33 mm., which amounts to 51 and 59 per
cent of length of tail-vertebrae. In two adult females, one from
Teton County, Wyoming, and one from Wheeler Peak, Nevada, the
least width of the underparts amounts to 55 and 60 per cent of the
greatest width of color of upper parts. Black tip of tail,
respectively, 23 and 19 mm., which amounts to 44 and 45 per cent
of length of tail-vertebrae.
From the other subspecies of small-sized weasels of more
northwestern occurrence, namely _anguinae_, _fallenda_,
_olympica_, _streatori_ and _gulosa_, _muricus_ differs in lighter
color of upper parts, wider light-colored underparts and
relatively longer black tip of tail.
_Skull._--Male (illustrated by 5 adults in table of measurements,
which see): See plate 7. As described in _Mustela erminea
richardsonii_ except that: Weight, 0.78 (Wheeler Peak) and 0.85
(Black Butte) grams; basilar length, 30.6 (29.8-31.2); length of
tooth-rows more or less than (approximately equal to) length of
tympanic bulla.
Female (illustrated by 6 adults in table of measurements, which
see): See plates 12-14. As described in _Mustela erminea
richardsonii_ except that: Weight, 0.60 (0.575-0.645); basilar
length, 28.0 (27.3-29.4); breadth of rostrum approximately 30 per
cent of basilar length.
In comparison with _streatori_, males average smaller in every
measurement taken with no overlap in most dimensions; 25 per cent
lighter; anterior margin of tympanic bulla more nearly flush with
squamosal, that is to say less protruded from braincase; in relation to
other dimensions of skull, braincase shallower anteriorly (at plane of
last molars) and deeper posteriorly (at anterior end of basioccipital).
Females average smaller in every measurement taken except mastoid and
zygomatic breadths which are actually more; 6 per cent lighter; in
relation to other parts of skull, preorbital and interorbital parts
slightly smaller; in relation to length of skull, braincase shallower.
Comparison with _invicta_ and _gulosa_ is made in the accounts of those
subspecies.
_Remarks._--The smallest males of the entire species are of this
subspecies and the females of it are barely larger than those of
_olympica_ and _gulosa_ and hence are among the three smallest. The
material now available consists only of one or a few specimens from
each of several widely separated localities. If as many specimens per
unit area were available as there are of the species _M. erminea_ from
southern British Columbia, geographic variation warranting the division
of _muricus_ into more than one subspecies might be revealed. Evidence
pointing in this direction is comprised in the pale color and small
size of the pair of adults from Wheeler Peak on the eastern border of
Nevada; the suggestion is that there is a distinct pale race of small
individuals in the isolated spots of boreal life-zone in the mountains
of the desert. The color and size of the specimens from the Toyabe
Mountains, and that from the Pine Forest Mountains, both places also in
Nevada, nevertheless, lend no support to this suggestion. Comparison of
specimens from the Rocky Mountains of Colorado with those from the
Sierra Nevada of California gives no basis for recognizing more than
one subspecies. Therefore, _Putorius streatori leptus_ Merriam with
type locality at Silverton, San Juan County, Colorado, falls as a
synonym of the earlier named _Putorius (Arctogale) muricus_ Bangs with
type locality at Echo, El Dorado County, California. Furthermore,
specimens from northern New Mexico, the southernmost known area of
occurrence for the subspecies (and for the species), are as large as
specimens from far north in the range of the subspecies, say, in
northwestern Wyoming; there is therefore no evidence of progressive
decrease in size to the southward as in advance of study I supposed
existed in _muricus_. This erroneous supposition was held because I
knew that there was a decrease in size to the southward in the species
as a whole and also in each of the subspecies _richardsonii_ and
_invicta_ directly to the north of _muricus_.
Intergradation with _invicta_ is shown by specimens from southwestern
Montana. Where the margins of the geographic ranges of _invicta_ and
_muricus_ approach one another elsewhere, low-lying territory, zonally
unsuited to the existence of the species, occurs along the Snake and
Columbia rivers, and precludes any chance of intergradation except
around the head of the Snake River Plains. Two specimens, here referred
to _muricus_, from Siskiyou County, California, in both color and
cranial characters, are intergrades with _streatori_ and might be
referred with almost equal propriety to _streatori_.
_Specimens examined._--Total number, 52, arranged alphabetically
by states, then by counties from north to south within each state.
Unless otherwise indicated, specimens are in the Museum of
Vertebrate Zoölogy, University of California at Berkeley.
=California.= _Siskiyou County_: head of Rush Creek, 6400 ft., 1;
Castle Lake, 5434 ft., 1. _Tehama County_: 2 mi. W Black Butte,
6800 ft., 1. _Placer County_: ridge W of Tahoe Pines, Lake Tahoe,
1; Blackwood Creek, 6250 ft., near Tahoe Pines, 1. _El Dorado
County_: Fallen Leaf Lake, 6500 ft., 1[33]; Echo, 1[75]. _Tuolumne
County_: Ten Lakes, 9200 ft., Yosemite Park, 1. _Mariposa County_:
Vogelsang Lake, 10350 ft., Yosemite Park, 1. _Mono County_:
Mammoth, 1[59].
=Colorado.= _Rio Blanco County_: Marvine, 1. _Boulder County_:
Camp Albion, 10600 ft., 1[60]; Boulder, 1[91]. _Denver County_:
Denver, 1[57]. _Park County_: Jefferson, 1[57]. _Gunnison County_:
near Placita in Gunnison County, 1[26]; Crested Butte, 9000 ft., 3
(1[91], 2[19]). _El Paso County_: Turkey Creek, SW Colorado
Springs, 6000 ft., 1[19]. _Chaffee County_: Arbourville, 1[91];
Hancock, 1. _Montrose County_: Coventry, 6800 ft., 1[19]. _San
Juan County_: Silverton, 1[91]; in San Juan County above
timberline, 1[87].
=Idaho.= _Bannock County_: West Fork of Rapid Creek, 9-1/2 mi. E
Pocatello, 1.
=Montana.= _Meagher County_: Camas Creek, Big Belt Mts., 4 mi. S
Ft. Logan, 1[91]. _Beaverhead County_: Donovan, 1[91]. _County_ in
question: Yellowstone Park, 1[75].
=Nevada.= _Humboldt County_: Alder Creek, 6000 ft., Pine Forest
Mts., 1. _Ormsby County_: 1/2 mi. S Marlette Lake, 8150 ft., 1.
_Nye County_: South Twin River, Toyabe Mts., 1[91]. _White Pine
County_: Baker Creek (8500 ft., 8675 ft., 11100 ft.), 3.
=New Mexico.= _Taos County_: Twining, 10700 ft., 1[91]. _Sandoval
County_: 9 mi. E Cuba, 9000 ft., 1. _Santa Fe County_: Saddle S of
Santa Fe Baldy, 11000 ft., Santa Fe Range, 1[1].
=Oregon.= _Wasco County_: Mill Creek, 20 mi. W Warmsprings, 1[91].
_Klamath County_: Fort Klamath, 1[91].
=South Dakota.= _Pennington County_: 4 mi. SE Hill City, 5300 ft,
2[76]; Pfander's Ranch, 3 mi. SSE Hill City, 5300 ft., 1[76];
Palmer Gulch, 3 mi. SE Hill City, 5300 ft., 1[76]; Spring Creek, 2
mi. W Oreville, 5500 ft., 1[76]. _Custer County_: 1/2 mi. E Sylvan
Lake, 6250 ft., 1[76].
=Washington.= _Columbia County_: Butte Creek, 1; Stayawhile
Spring, 5150 ft., 1:
=Wyoming.= _Crook County_: 5 mi. NW Sundance, 5900 ft., 1[93].
_Teton County_: Whetstone Creek, 2[76]; 1/4 mi. E Moran, 6700 ft.,
1[93]. _Sublette County_: 1/2 mi. NE Pinedale, 7500 ft., 1[93].
_Albany County_: 30 mi. N and 10 mi. E Laramie, 6560 ft, 1[93]; 26
mi. N and 4-1/2 mi. E Laramie, 6960 ft., 1[93]. _Carbon County_: 8
mi. N and 19-1/2 mi. E Savery, 8800 ft., 2[93].
=Mustela erminea? angustidens= (Brown)
Plates 7, 12, 13 and 14
_Putorius cicognanii angustidens_ Brown, Mem. Amer. Mus. Nat.
Hist., 9 (pt 4):181, pl. 17, 1908:
_Mustela cicognanii angustidens_, Hay, Iowa Geol. Surv. Bull.,
23:32, 1914; Hay, Carnegie Inst. Washington, Pub. no. 322A:252,
October 15, 1924; Hay, _ibid_., Pub. no. 390 (vol. 2): 528, 1930;
Hall, _ibid_., Pub. no. 473:111, 112, November 20, 1936:
_Type._--Female, adult, skull and lower jaws lacking zygomata,
right P2 and incisors, no. 12432, Amer. Mus. Nat. Hist.; from
Conard Fissure, four miles west of Willcockson, Newton County,
Arkansas; obtained sometime in the period 1903 to 1905 inclusive
(see plates 8, 14).
_Range._--Known only from the Pleistocene deposit in Conard
Fissure, at the type locality in northern Arkansas.
_Description._--_Skull._--Male (based on nos. 12437, 12441 and
12444): See measurements and plates 7 and 8; weight, unknown;
basilar length, 38:1 (36:6-39:2); length of tooth-rows more than
length of tympanic bulla; breadth of rostrum measured across
lacrimal processes less than a third of basilar length;
interorbital breadth ordinarily equal to distance between glenoid
fossa and posterior border of external auditory meatus; zygomatic
breadth probably averaging approximately the same as distance
between last upper molar and jugular foramen.
Female (based on nos. 11766 and 12435): See measurements and plates
8, 12-14; weight, unknown; basilar length, 34:0 (32:5-35:1);
length of tooth-rows more than length of tympanic bulla; breadth
of rostrum about equal to (more or less than) 30 per cent of
basilar length; interorbital breadth less than distance between
glenoid fossa and posterior border of external auditory meatus;
zygomatic breadth probably less than distance between last upper
molar and jugular foramen.
Comparison of the cranial description given above with those of the
American races of _erminea_ from the far north will show that
many characters are held in common--more than with more southern
subspecies of _erminea_.
_Remarks._--The ten specimens studied by the writer fall into two
groups of six larger individuals and four smaller. Upon comparing these
with each sex of the three species of American Recent weasels,
_frenata_, _erminea_ and _rixosa_, it is seen that size, and to some
degree shape, rule out of consideration both sexes of _rixosa_ and also
males of _frenata_. Thus we are left with females of _frenata_ and
males and females of _erminea_. So far as size is concerned, it can be
assumed that the larger specimens are females of _frenata_ and that the
smaller are males of _erminea_. This assumption has in its favor also,
the fact that the postglenoidal length of the skull accords with that
in Recent specimens. The difference in this regard in Recent animals is
that the postglenoidal length of the skull, expressed as a percentage
of the total (condylobasal) length of the skull, amounts to:
in _frenata_ in _erminea_
[M] ordinarily less than 46 [M] ordinarily more than 46
[F] less than 47 [F] more than 48
In the fossils the percentage for the larger skulls is 46; for the
smaller skulls it is 48.
It may be that the ten fossil skulls are six female _frenata_ and four
male _erminea_ but I think not. In the first place a skull of different
shape, seemingly of the _frenata_ stock, is known from the deposit and
it is almost certain that two subspecies of the same species would not
occur at the same place at the same time. It is possible, of course,
that parts of the deposits were laid down at times so far apart that a
shift in geographic range of two subspecies had occurred. This one
skull, seemingly of the _frenata_ stock, is the type of _Putorius
gracilis_ Brown (see p. 404) and was regarded as the only known
specimen of _gracilis_. Regardless of the specific identity of this one
specimen named _gracilis_, the chances of obtaining otherwise from a
deposit, like that in Conard Fissure, six females of frenata and four
males of _erminea_ without a male _frenata_ or a female of _erminea_
coming to light are so slight as strongly to incline me to the view
that the six larger specimens are males of the same species to which
the 4 smaller specimens belong. By either this interpretation, or the
one initially considered (of female _frenata_ and male _erminea_), the
animals from the fissure are at least subspecifically distinct from any
American Recent weasel. Furthermore, by this latter interpretation each
sex of this weasel, _angustidens_, is intermediate between the
_frenata_ and _erminea_ stocks in the feature of postglenoidal length
which feature, at any place where the two Recent species occur
together, serves to distinguish one from the other. In the northernmost
subspecies of _erminea_ (_arctica_ for example) the postglenoidal
length in some males is no longer than in males of _frenata_.
Considering general size, _angustidens_ agrees better with _erminea_
than with frenata and this circumstance has influenced me to place
_angustidens_ as a subspecies of _erminea_.
Today, _erminea_ is not known to occur nearer Conard Fissure than
northern Iowa, more than 400 miles to the northward. In comparison with
the race there, _bangsi_, males of _angustidens_ are of approximately
the same size but in the shorter distance between the glenoid fossa and
anterior margin of the tympanic bulla, and also in the lesser
postglenoidal length of the skull, _angustidens_ resembles the
northernmost American subspecies of _erminea_. Females of _angustidens_
differ more from any living weasel than the males do. The females are
much larger than those of _bangsi_, and among living American races of
_erminea_ most closely resemble intergrades between _arctica_ and
_richardsonii_ which intergrades are found approximately 1700 miles to
the north of Conard Fissure. In females, the preorbital part of the
skull in _M. e. arctica_ is broader and in _M. e. richardsonii_
narrower than in _angustidens_. If it seems strange that females of
_angustidens_ resemble one subspecies whereas males, in size, resemble
another subspecies almost a thousand miles distant, it should be
remembered that the degree of sexual dimorphism varies much from one
subspecies to another in the Recent animals. An example is furnished by
_Mustela erminea fallenda_ and _Mustela erminea invicta_.
The assemblage of mammals from Conard Fissure includes several species
of boreal predilections which, like _Mustela erminea_, now occur only
much farther north than Arkansas. At one time the edge of the sheet of
ice was only about 200 miles north of Arkansas. It may be significant
that the cranial characters of the female ermine from the Fissure, and
qualitative cranial characters of males from there, are most nearly
approximated among Recent weasels by those which live along the
southern edge of the frozen tundra.
In view of what has been said, the possibility should be considered
that the distinctive cranial features of _angustidens_ may be the
result of evolutionary change in time as well as of geographic
variation resulting from horizontal placement.
=MUSTELA RIXOSA= (Bangs)
Least Weasel
(Synonymy under subspecies)
_Type._--_Putorius rixosus_ Bangs, Proc. Biol. Soc. Washington,
10:21, February 25, 1896.
_Range._--From Norway and Switzerland eastward through Siberia and
all the way across North America, but unknown from Iceland,
Greenland and the Arctic islands west of Greenland; in North
America, from the Arctic Life-zone south to Central British
Columbia, Montana and into parts of the Upper Austral Life-zone as
in the eastern half of the continent.
The southern extension of range in the Appalachians (to North
Carolina) is not duplicated in the Rocky Mountains of western
North America probably because the region there suitable for
_rixosa_ south of Central British Columbia and Montana is occupied
by the almost equally small _Mustela erminea muricus_ and related
subspecies which seem to fill the ecological role that _rixosa_
plays where it occurs. The small size of females of _M. erminea
cicognanii_ in New England may similarly account for the absence
of _rixosa_ there.