Chapter IX: Introduction (8)

The color of the upper parts is uniform and the color pattern varies less than in geographically adjoining races. The white color of the underparts is restricted to a thin line on the abdominal region, but widens out posteriorly in the inguinal region and anteriorly over the pectoral region, throat, chin and lower lips. The upper lips are brown. The brown of the upper parts extends around in front of each foreleg, the two brown areas not quite meeting on the lower throat. The above description applies to each of the 19 specimens examined with regard to these details. Every specimen seen in the winter coat was brown, not white.

_Specimens examined._--Total number, 20, arranged by counties from
north to south. Unless otherwise indicated, specimens are in the
U. S. National Museum.

=Washington.= _Clallam County_: Clallam Bay, 2 (1[74], 1[94]);
Elwha, 2[10]; Johnsons Ranch, 1[60]; Happy Lake, 1[60]; Boulder
Lake, 2[60]; near head of Soleduc River, 4500 ft., 1; 12 mi. S
Port Angeles, 1[10]. _Jefferson County_: Hayes Cr., 2000 ft.,
Elwha River, 2; head N Fork Quinault River, 4000 ft., 1;
Duckabush, 3; N Fork Skokomish River, 1. _Mason County_: Lake
Cushman, 2[76]; 4 mi. S Olympia, 1.

=Mustela erminea streatori= (Merriam)

Ermine

Plates 5, 6, 7, 12, 13 and 14

_Putorius streatori Merriam_, N. Amer. Fauna, 11:13, pl. 2, figs.
5, 5a, 6, 6a, June 30, 1896.

_Putorius cicognanii_, Baird, Mamm. N. Amer., p. 161, 1858 (part
unless no. 2395 was a female of _M. frenata_).

_Putorius pusillus_, Baird, Mamm. N. Amer., p. 159, 1858 (part).

_Putorius (Gale) vulgaris_, Coues, Fur-bearing animals, p. 102,
1877 (part).

_Mustela streatori streatori_, Miller, U. S. Nat. Mus. Bull.,
79:96, December 31, 1912; Grinnell, Univ. California Publ. Zoöl.,
40:101, September 26, 1933.

_Mustela cicognanii streatori_, Hall, Murrelet, 12:22, January,
1931; Hall, Univ. California Publ. Zoöl., 38:417, November 8,
1932.

_Mustela erminea streatori_, Hall, Journ. Mamm., 26:77, February
27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

_Mustela rixosa_, Beer, Journ. Mamm., 29:296, August 31, 1948.

_Type._--Male, adult, skull and skin; no. 76646, U. S. Nat. Mus.,
Biol. Surv. Coll.; Mount Vernon, Skagit Valley, Skagit County,
Washington; February 29, 1896; obtained by D. R. Luckey, original
no. 3.

The skull is unbroken and the teeth all are present and entire.
The skin, in brown winter pelage, is stuffed and in good
condition.

_Range._--Western Washington along eastern side of Puget Sound,
western Oregon from the Cascades to the coast, and northwestern
California south in the humid coastal district nearly to the
Golden Gate. See figures 25, 27 on pages 95, 149.

_Characters for ready recognition._--Differs from _M. e.
anguinae_, in male, by sagittal crest present and hind foot
ordinarily less than 33.5, in female by hind foot less than 27.5,
basilar length less than 30.2; from _M. e. fallenda_, in both
sexes, by black tip of tail less than half of length of
tail-vertebrae, in males hind foot less than 33.7, tympanic bulla
about same length as, instead of longer than, upper tooth-rows;
weight of skull less than 1-1/4 grams, in female weight of skull
less than 0.7 grams, length of lateral side of P4 less than 4 mm.;
from _M. e. olympica_, by larger size, in males hind foot more
than 33.0, basilar length ordinarily more than 32.5, in females by
hind foot ordinarily longer than 24, by breadth of rostrum more
than 8.6, depth of braincase at posterior border of upper molars
more than 7.6; from _M. e. gulosa_ and _muricus_, in both sexes,
by upper lips brown (not white), light color of underparts
extending down hind leg no farther than knee, depth of skull at
posterior border of upper molars more than 7.7 in females and
ordinarily more than 9.6 in males, further from _muricus_ by tail
more than 62 in males and more than 49 in females; from _M. e.
invicta_ by upper lips white (not brown), in males hind foot more
than 36 and basilar length more than 35, in females hind foot more
than 29.5 and basilar length more than 30.5.

_Description._--_Size._--Male: Twelve adults from Blaine and
Tillamook, Oregon, yield average and extreme measurements as
follows: Total length, 255 (245-275); length of tail, 72 (64-80);
length of hind foot, 31.5 (30.0-33.5).

Female: Seven adults from Blaine and Tillamook, Oregon, yield
average and extreme measurements as follows: Total length, 214
(193-230); length of tail, 55 (50-63); length of hind foot, 25
(24-27).

_Color._--Winter and summer pelages indistinguishable; upper parts
uniform and ranging from Raw Umber to slightly darker (16_n_), and
about tones 1 to 3 of Dark Chocolate of Oberthür and Dauthenay,
pl. 342; underparts white, in summer rarely with a faint buffy
suffusion in pectoral region; color of underparts extends from
chin, and often lower lips, posteriorly to inguinal region,
distally on posterior sides of forelegs onto antipalmar faces of
toes (sometimes interrupted at and above wrist) and on medial
sides of hind legs hardly to knee. Least width of color of
underparts averaging, in twelve adults from Blaine and Tillamook,
10 (0-47) per cent of greatest width of color of upper parts.
Black tip of tail, in same series, averaging 28 (24-33) mm. which
is 40 (34-47) per cent of length of tail-vertebrae.

_Skull._--Male (based on 12 adults): See measurements and plates
5-7. As described in _Mustela erminea richardsonii_ except that:
Weight, 1.1 (1.0-1.2) grams; basilar length, 33.2 (32.5-33.8);
length of tooth-rows more or less than (about same as) length of
tympanic bulla.

Female (based on 7 adults): See measurements and plates 12-14. As
described in _Mustela erminea richardsonii_ except that: Weight,
0.64 (0.60-0.67) grams; basilar length, 28.5 (27.6-29.5); breadth
of rostrum more than 30 per cent of basilar length.

Comparison with _anguinae_, _fallenda_, _olympica_, _gulosa_ and _muricus_ is made in accounts of those subspecies.

_Remarks._--This weasel is rare in collections and the best material of it was obtained by Alex Walker in Tillamook County, Oregon, where he resides. The almost ideal series of 30 specimens showed the range of secondary sexual, age, and individual variation expectable in the small ermines of the Pacific Coast of the United States and was the means of allowing satisfactory decision on questions of classification in the related subspecies in which individuals are of comparable size.

Intergradation with each of the geographically adjoining subspecies, _olympica_, _fallenda_, _invicta_, _gulosa_ and _muricus_ is shown by specimens examined. With the last mentioned subspecies, intergradation is shown by two specimens from as far south as Siskiyou County, California, assigned to _muricus_.

The application of the name _streatori_ is difficult because it was based on a specimen from a place where two clines cross. The north-south cline is one of size which decreases to the south. The east-west cline is one of intensity of color, the westernmost (coastal) population being the most intensely colored. The type locality of _streatori_ is at the place where two lines perpendicular to one another, and representing the two clines, cross. This intersection is near the place where the ranges of several subspecies meet. The nomenclatural question is, to which one of 6 subspecies should the name _streatori_ apply. Specimens from barely within the geographic boundaries of four of these subspecies so closely resemble topotypes of _streatori_ that a student with material at his disposal from only the area about Puget Sound naturally would apply the name _streatori_ to all of his specimens, and knowing even of the arrangement adopted in the present account the student will have difficulty in identifying his specimens according to it. Not only will the student find the arrangement difficult, but probably unsatisfactory if he thinks of _streatori_ as being the kind of animal represented by topotypes. I conceive of topotypes of _streatori_ as being nontypical of the subspecies; they are intergrades with _fallenda_. My aim was initially to work out the geographic ranges of subspecies and only subsequently to apply names, according to which type localities fell within the previously determined geographic ranges. By this procedure no greater weight was given to a holotype and to topotypes than to specimens from any other locality.

Of the 40 specimens seen in winter pelage, only one is white. It is from Darrington in the Cascade Mountains of Washington. The 39 others are brown and I doubt that the white pelage ever occurs in the low coastal territory included within the geographic range of _streatori_. This subspecies resembles _anguinae_ and _olympica_ in the great extension of area of the dark-colored upper parts at the expense of the area of the light-colored underparts. The usual arrangement is one where the brown of the two sides nearly meets on the midventral line leaving a sizable, inguinal area of light color connected by a thin line to the sizable area of light color on the pectoral region. The light color of the pectoral area ordinarily is continuous with the light-colored area of the throat and chin but the dark color of the upper parts extends around in front of each foreleg. These extensions of dark color meet on the chest in only 2 of the 56 specimens examined in this regard. Across the abdomen the dark color is continuous in 4 of the 56 specimens. The lower lips are brown instead of white in only 3 individuals and in 2 of these the lip of one side is brown and its opposite is white. The variation in color-pattern is less than in _anguinae_ or than in _fallenda_.

_Specimens examined._--Total number, 63, arranged alphabetically
by states, then by counties from north to south in each state.
Unless otherwise indicated, specimens are in the U. S. National
Museum.

=California.= _Humboldt County_: 10 mi. NE Carlotta, 1[74].
_Mendocino County_: Russian Gulch State Park, 1[74]. _Sonoma
County_: Mouth of Gualala River, 1[74].

=Oregon.= _Clatsop County_: Astoria, 1. _Tillamook County_:
Tillamook, 16 (14[14], 1[59]); Blaine, 12 (7[14], 2[59], 1[93],
2[76]). _Washington County_: Beaverton, 1[60]; Forest Grove,
1[36]. _Clackamas County_: Oregon City, 1[46]. _Lincoln County_:
Newport, 1. _Linn County_: Sico, 1[46]. _Lane County_: Vida Fish
Hatchery, 2[101]; McKenzie Bridge, 1[101]; Mercer, 1[75]. _Klamath
County_: Deschutes River, 6 mi. E Crescent Lake, 1[101]. _Douglas
County_: Gardiner, 1[60]. _Curry County_: Port Orford, 1; Gold
Beach, 2[60].

=Washington.= _Skagit County_: N end Whidby Island opposite
Deception Pass, 1; Hamilton, 4; Mt. Vernon, 3. _Snohomish County_:
Oso, 550 ft., 1; Darrington, 600 ft., 1. _Pacific County_:
Wallicut River, 2 mi. E Ilwaco, 1[74]. _Wahkiakum County_: 4 mi.
E. Skamokawa, 3[74]. _Cowlitz County_: 4 mi. E mouth Kalama River,
2[74]; 6 mi. E mouth Kalama River, 1[74]. _Skamania County_: 15
mi. N Govt. Springs, 1300 ft., 1.

=Mustela erminea gulosa= Hall

Ermine

Plates 5, 6, 7, 12, 13 and 14

_Mustela erminea gulosa_ Hall, Journ. Mamm., 26:84, February 27,
1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

_Putorius streatori_ Merriam, N. Amer. Fauna, 11:14, June 30, 1896.

_Type._--Male, subadult, skull and skin; no. 81998, U. S. Nat.
Mus., Biol. Surv. Coll.; Trout Lake, Klickitat County, Washington;
February 3, 1897; obtained by P. Schmid, original no. 147.

The skin is in brown winter pelage, and appears to have been made
up from a skin split along the midventral line from the anus to
the forelegs. It probably was dried by a trapper, is well made,
and lacks a patch of hair on the left flank but otherwise is in
good condition. The skull lacks the central part of the left
zygomatic arch and the posterior two-thirds of the right one. The
right m2 is represented only by an abortive stump or the broken
root, and i1 and i2 on each side are absent; otherwise, the teeth
all are present and entire.

_Range._--Cascades of Washington from northeastern King County
south to Mount Adams. See figures 25, 27 on pages 95, 149.

_Characters for ready recognition._--Differs from _M. e. invicta_
and _fallenda_, in both sexes, by anterior margin of tympanic
bulla flush with squamosal rather than projecting below floor of
braincase (difference slight in females), in males hind foot less
than 33.5, weight of skull less than 1-1/4 grams, basilar length
less than 33.9, in females by total length less than 222, hind
foot shorter than 26, weight of skull less than 0.7 grams, basilar
length less than 29; from _M. e. muricus_, in both sexes, by upper
parts darker, tone 4 of Chocolate or darker (see description of
color) least width of light-colored underparts averaging one-third
instead of approximately two-thirds of greatest width of
dark-colored upper parts, in males, on the average, tail more than
65, weight of skull more than 0.90 grams, basilar length more than
30.8 mm.; from _M. e. streatori_, in both sexes, by upper lips
white (not brown), light color of underparts extending down hind
legs 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.

_Description._--_Size._--Male: One adult and four subadults from
Mount Rainier yield average and extreme measurements as follows:
Total length, 253 (238-266); length of tail, 75 (70-83); length of
hind foot, 31.5 (30-33). Corresponding measurements of 9 subadults
from Trout Lake are: 257 (233-282); length of tail, 76 (56-83);
length of hind foot, 30.2 (26-33).

Female: Of adults, 2 from Mount Rainier and 2 from Trout Lake
measure as follows: Total length, 202, 203, 216, 210; length of
tail, 54, 52, 57, 51; length of hind foot, 24, 24, 25, 24. The
averages for these females are 208, 54, 24.3.

_Color._--As described in _Mustela erminea richardsonii_ except
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.

_Characters for ready recognition._--Differs from both _Mustela erminea_ and _Mustela frenata_ by tail a fourth or less of length of head and body and without a black tip (at most a few black hairs at extreme tip in rixosa), and from _M. frenata_ and from _M. erminea_ in regions where it and _rixosa_ occur together, by basilar length of skull less than 32.5 in males and less than 31.0 in females.

_Characters of the species._--Size small: Total length less than 250 in males and 225 in females; tail a fourth or less of length of head and body, and without a black pencil and at most with a few black hairs at extreme tip; caudal vertebrae 11 to 16, normally 15 in _M. r. rixosa_, and 11 in one _M. r. eskimo_ examined; skull with long braincase and short precranial portion, thus essentially same shape as in _M. erminea_ but the largest males of _M. rixosa_ always with a lesser basilar length that even the smallest females of _M. erminea_ or _M. frenata_ of the same geographic area. In fact no specimens of _M. frenata_ have skulls so small as the largest _M. rixosa_, and skulls of equal size of _M. erminea_ and _M. rixosa_, for example, _M. erminea muricus_ of Colorado and _M. rixosa eskimo_ of Alaska, differ in that when the skulls are viewed from directly above those of _rixosa_ have the mastoid processes more prominent, or the braincase is higher in relation to its width or both differences together prevail. Stated in another way, comparison of skulls of equal size of _rixosa_ and _erminea_ shows that in the latter the braincase is more nearly flat and is wider above and in front of the mastoid processes; therefore, the greatest breadth of the braincase equals or exceeds the mastoid breadth, whereas the reverse is ordinarily true of _rixosa_.

_Geographic variation._--In the Old World four subspecies are currently recognized (see Allen, 1933:316) and the same number is here recognized in North America. Length of the tail, length of head and body and hind foot, breadth of the rostral part of the skull in relation to its length, and position on the side of the head of the line of demarcation between the dark color of the upper parts and the white underparts, are the features in which geographic variation has been detected. The general impression is that the amount of geographic variation is much less than in _Mustela frenata_ and only slightly less than in _Mustela erminea_ of the same geographic area.

_Nomenclature._--It is exceptional for a species which occurs in both the Old-and New-World to take its specific name from New World material, especially if the name was proposed as recently as 1896; most circumboreal species take their names from descriptions of European specimens. Although the least weasel, _Mustela rixosa_ (Bangs) 1896, seems now to be an exception, it may yet turn out that the first available name was based on European material. Zimmermann (1943) shows that the least weasel actually was named on the basis of European material long before 1896 and concludes that the name _Putorius minutus_ Pomel, 1853, based on a specimen from France, is the first available name.

Because _Putorius_ nowadays is relegated to subgeneric rank under the generic name _Mustela_, we have for consideration the name-combination _Mustela minuta_ (Pomel). Unfortunately for Zimmermann's conclusion, _Mustela minuta_ Pomel is not available because it is preoccupied by _Mustela minuta_ Gervais [= _Palaeogale minuta_ (Gervais), 1848-1852--see Simpson, 1946: 2, 12], a name applied to another species of small mustelid from the Oligocene or lower Miocene deposits of Europe.

Some other early names thought by Zimmermann (1943:290) to have been based on the dwarf weasel of Europe are judged to be _nomina nuda_ and therefore are to be ignored.

The name _Mustela minor_ Nilsson 1820 was thought by Miller (1912:402) to be a renaming, and hence a synonym, of _Mustela nivalis_ Linnaeus. If that is the case the name does not apply to the dwarf weasel. If the name _Mustela minor_ Nilsson was instead based on the dwarf weasel, the name might still be unavailable, depending on rulings on secondary homonyms, because the name might be preoccupied by _[Lutra] minor_ Erxleben 1777 which is a synonym of _[Mustela] lutreola_ Linnaeus 1766. Two names seemingly available for weasels, and in use for them today, which might replace _rixosa_ as the name of the species, are, first, _Mustela boccamela_ Bechstein, 1801, of Sardinia [= _Mustela nivalis boccamela_ of Miller, 1912, 405] and second, _Putorius numidicus_ Pucheran, 1855, of Morocco and Algeria [= _Mustela numidica_ of Allen, G. M., 1939, 183]. As they stand in the current literature, _Mustela numidica_ is a species distinct from the dwarf weasel and the other name, _Mustela nivalis boccamela_, is an insular subspecies of the mouse weasel. Zimmermann (1943:292), however, implies that _M. numidica_ may belong to the dwarf weasel group when he says "Ob auch _iberica_ BARR.-HAM. als Unterart zu _minuta_ POM. zu stellen ist, soll hier nicht untersucht werden, ebensowenig die von CABRERA vermutete Zugehörigkeit der grossen nordafrikanischen _M. numidica_ PUCH. zur '_iberica_-Gruppe'." The answer to this problem requires a taxonomic, rather than a nomenclatural, decision. Whether either _M. numidica_ or _M. boccamela_ are conspecific with the dwarf weasel I cannot at this time ascertain for want of adequate specimens. Because these two names, _M. boccamela_, and _M. numidica_, are assigned to kinds of weasels which are currently regarded as specifically distinct from the dwarf weasel, and because all the other names which certainly have been assigned to Old World populations of the dwarf weasel before 1896, so far as I know, are _nomina nuda_ or are preoccupied, the next available name, _Mustela rixosa_ (Bangs, 1896), is here employed.

_Remarks._--This species may have a wider geographic range in northeastern North America than is now known. Strong (1930:7) writes that the Naskapi Indians of the interior country of Labrador between Hamilton Inlet and Ungava Bay "have only one name for weasel, _mé-tah-kwut_, but they say there are three kinds in their territory, a large, an intermediate, and a very small weasel. The latter suggests the least weasel . . . which has not been recorded from northern Labrador."

In the northern part of the range of the species, the winter pelage is white and the summer pelage is brown. In the southern part of the range, that is in the range of the subspecies _allegheniensis_, the winter pelage is either brown or white and the time of the molt into winter pelage is irregular; each of eleven individuals from Pennsylvania, Michigan and Ohio, taken in December, January, February and March is mostly white but retains some considerable part of the brown pelage of the previous coat on top of the head and usually also along the midline of the entire dorsum. These eleven animals include individuals of each sex. Of each sex, some are adults and some are subadults. Therefore, the delayed or incomplete fall molt, at present, cannot be correlated with either sex or with any particular age. No wild-taken specimens of _M. erminea_ or of _M. frenata_ of the same region show this delayed or incomplete molt.

Possibly this delay or incompleteness of molt is the result of the same cause that lies behind the birth of some _M. rixosa_ in midwinter. As listed below, several litters of young have been found in midwinter. In fact it appears that in the United States, young may be born in every month of the year although, according to existing information, more litters are produced in spring and in winter than in summer and autumn. Many juveniles and young of _allegheniensis_ examined in study collections clearly were born in spring but about as many seem to have been born in midwinter as at any other time (in the light of present knowledge) and this is in contrast to what we know of the two other species of American weasels since their young, so far as known, are born in spring.

One instance is worthy of detailed comment. An adult female, no. 783 Ohio State Museum, taken on January 31, 1931, at Vinton, Meigs County, Ohio, bears the following notation on the attached label "nest plowed out of ground. Very small young escaped--marked like parent. [F] was nursing." The enlarged mammae on the dried skin substantiate the statement that the female was nursing young. She has a brown mask continuous from one ear through the eye, across the forehead and through the other eye to the opposite ear. On each side of the body a stripe of brown 5 to 10 mm. wide extends from the upper part of the foreleg back to the thigh and base of the tail, uniting there with its opposite and covering the tail. There are a few spots of brown on the shoulders, and rump and one on the middle of the back. Otherwise the specimen is white. One implication of the statement on the label that the young which escaped were marked like the parent (presumably this female parent) is that this female is a partial albino. I am more inclined, however, to the view that there was an unseasonable activity of the particular glands of internal secretion the hormones of which promote embryonic growth and that these glands, or others controlled by them, were in some way responsible for an abnormal progress of molt, or for a reversal of molt in that one molt began before the previous molt had been completed.

Excepting this one specimen, no. 783 from Vinton, Ohio, all of those in transitional pelage indicate that the direction of the molt pattern is the same as in _M. frenata_ and _M. erminea_. That is to say, the autumnal molt begins on the midventral line and the molt in spring begins on the mid-dorsal line. Furthermore, the normal progress of each molt appears to follow the same pattern that has been described above for _Mustela frenata_.

A possible explanation of unseasonal molt in the southeastern area of occurrence of the species _Mustela rixosa_, and a possible explanation of the abnormal molt of the female from Vinton, Ohio, is that the species has only relatively recently invaded the area, and has had insufficient time to adjust the physiology of its molting mechanism to the longer periods of daylight that obtain later in autumn and earlier in spring than farther north. In the other two species of American weasels, the change in length of periods of light, it will be recalled, is known to indirectly control both molt and some changes in the sexual cycle. Wright (1942B:109) has shown that molt in spring precedes by one or two months the birth of young in _M. frenata_, that the two phenomena are correlated in a way that is statistically significant, and recognizes that progressively longer periods of daylight may be the causal stimulus. The suggestion made above that _M. rixosa_ does not live in New England or in the Rocky Mountains of the western United States because each of the two areas already is inhabited by weasels of almost equally small size, is in line with the idea that _rixosa_ is a recent immigrant to America, or more precisely that _rixosa_ arrived later than _erminea_.

_Natural History._--Habitat and Numbers.--Soper (1946:136) recounts that near the junction of the Antler and Souris rivers, Manitoba, this species occurs "both in the river valleys and on the upper prairies," and later (1948:55), with reference to the Grand Prairie of the Peace River region of Alberta, writes that the least weasel "inhabits both parklands and mixed wood forest environments."

At most times, wherever found, the least weasel is regarded as rare. Not only mammalogists regard it as rare and as a desirable catch, but Indians likewise value it, probably because of its rarity. For example, Osgood (1901:69-70), who caught a female least weasel at Tyonek, Alaska, writes that: "The natives regard the capture of one of these rare animals as a piece of great good fortune. One old Indian who frequently visited our cabin told us that his brother who had caught one when a small boy had in consequence become a 'big chief'; and he assured me that since I had caught one I must surely be destined to become a man of great wealth and power."

Swenk's (1926:313-330) account of the species in Clay County, Nebraska, shows, however, that the animal was far more abundant in 1916 and 1917 than subsequently and inferentially than it was before 1916. Clearest proof of multiannual fluctuation is provided by P. O. Fryklund's (Swanson and Fryklund, 1935:120-126) receipt of weasels from Roseau County, Minnesota. From 1895 to 1932 he had approximately equal opportunity to receive least weasels each year. Those which came to his attention were distributed by years as follows: 1895-1927, 7 individuals in all; winter of 1927-28, 3 individuals; winter of 1928-29, 59 individuals; 1929-1930, 84 individuals; 1930-1935, 3 individuals. "These records indicate a very definite increase in the abundance of least weasels in the Roseau region [in] the two years from the autumn of 1928 to the spring of 1930. Mr. Fryklund has handled 166 least weasels in his 40 years in Roseau County, and of these, 143 were taken in the two years mentioned."

The maximum home range of the least weasel is two acres and a weasel seldom travels farther than ten rods from its burrow according to Polderboer (1942:146) who, in the period December 20, 1939, to January 2, 1940, studied four least weasels and one long-tailed weasel on a 144 acre farm in Butler County, Iowa.

Behavior

Of the voice, Llewellyn (1942:441) records that his captive specimen taken in Virginia uttered a shrill shriek when seizing prey or when teased. When excessively annoyed the weasel also emitted musk.

The sense of smell is used in hunting as was witnessed by George L. Fordyce; he observed a least weasel following the scent of a _Peromyscus_ and saw the least weasel overtake and kill the mouse (Seton, 1929 (2):637).

At a nest in a clover stack, in Manitoba, Criddle (1947:69), on December 27, 1946, found the least weasel "to have been rather remiss in its sanitary habits as its pile of dung was almost, or quite, touching the nest and only just to the side of its entrance." There were 117 voids.

Enemies

The great-horned owl, barn owl and long-tailed weasel are to be counted as enemies since Nelson (1934:252) found the fur, skull and other fragments of the skeleton of a least weasel in one of 26 pellets of the great-horned owl in Wisconsin; Handley (1949:431) found the skull and other skeletal remains of a least weasel in one of 22 pellets of the barn owl in Virginia; and Polderboer, Kuhn and Hendrickson (1941), in Iowa, found the remains of a least weasel in the den and scats of a _Mustela frenata_. A domestic cat in Michigan killed a least weasel (Dearborn, 1932B:277).

Food

Mice are killed by the least weasel biting into the back of the head and neck according to Allen (1940:460) who reported upon the growth of five young, from Michigan, that he had in captivity. He further states that a weasel was able to kill a mouse in 30 seconds. One large _Microtus_ introduced into the cage slept with a weasel for several days and ate parts of the mice that the weasel killed but then the weasel killed this mouse! Llewellyn (1942:440-441), in writing of a captive from Virginia, says: "When a live mouse was placed in the cage, the weasel sprang upon it almost instantly. Grasping the mouse by the back of the head, the weasel bit its victim through the skull several times in rapid succession and held on with its sharp teeth. The sound of the teeth piercing the bone was distinctly audible at a distance of several feet. During this interval the weasel hugged the mouse closely with its fore legs and pressed it firmly to its belly through a kicking motion of the hind legs. The hold on the back of the head was not relinquished until the mouse was dead. The killing took only a few seconds. Upon releasing the mouse the weasel usually came to the front of the cage and inspected the observer for an interval of several seconds after which it returned to its prey and began its meal at once. Sometimes the blood would be licked from the wound in the back of the head or perhaps an ear would be chewed a bit and the blood licked off, but never did the weasel 'cut the throat' of its prey and 'suck the blood.'