19, 1945, is the name applied today to the ermine of the western
Great Lakes region.
In 1925 when this study was begun, the American weasels (subgenus
_Mustela_ proper) were arranged as belonging to 47 kinds (including
subspecies) of 29 full species. In the present account a total of 68
kinds, belonging to 4 full species are recognized in the subgenus
_Mustela_. The increase in number of subspecies and the decrease in
number of species are the nomenclatural results ordinarily obtained in
this decade from a systematic study of a genus of American mammals.
CHECK-LIST OF AMERICAN SPECIES AND SUBSPECIES OF THE GENUS MUSTELA
Subgenus =MUSTELA= Linnaeus
PAGE
_Mustela erminea_ 87
_Mustela erminea arctica_ (Merriam) 96
_Mustela erminea polaris_ (Barrett-Hamilton) 103
_Mustela erminea semplei_ Sutton and Hamilton 105
_Mustela erminea kadiacensis_ (Merriam) 108
_Mustela erminea richardsonii_ Bonaparte 110
_Mustela erminea cicognanii_ Bonaparte 118
_Mustela erminea bangsi_ Hall 124
_Mustela erminea invicta_ Hall 128
_Mustela erminea alascensis_ (Merriam) 131
_Mustela erminea salva_ Hall 135
_Mustela erminea initis_ Hall 136
_Mustela erminea celenda_ Hall 139
_Mustela erminea seclusa_ Hall 141
_Mustela erminea haidarum_ (Preble) 142
_Mustela erminea anguinae_ Hall 145
_Mustela erminea fallenda_ Hall 148
_Mustela erminea olympica_ Hall 153
_Mustela erminea streatori_ (Merriam) 155
_Mustela erminea gulosa_ Hall 159
_Mustela erminea muricus_ (Bangs) 161
_Mustela erminea angustidens_ (Brown) 165
_Mustela rixosa_ 168
_Mustela rixosa eskimo_ Stone 181
_Mustela rixosa rixosa_ Bangs 184
_Mustela rixosa allegheniensis_ Rhoads 187
_Mustela rixosa campestris_ Jackson 190
_Mustela frenata_ 193
_Mustela frenata noveboracensis_ (Emmons) 222
_Mustela frenata occisor_ (Bangs) 230
_Mustela frenata primulina_ (Jackson) 232
_Mustela frenata arthuri_ Hall 241
_Mustela frenata olivacea_ Howell 244
_Mustela frenata peninsulae_ Rhoads 250
_Mustela frenata spadix_ (Bangs) 252
_Mustela frenata longicauda_ Bonaparte 262
_Mustela frenata oribasus_ (Bangs) 270
_Mustela frenata alleni_ (Merriam) 274
_Mustela frenata arizonensis_ (Mearns) 276
_Mustela frenata nevadensis_ Hall 280
_Mustela frenata effera_ Hall 291
_Mustela frenata washingtoni_ (Merriam) 294
_Mustela frenata saturata_ (Merriam) 297
_Mustela frenata altifrontalis_ Hall 300
_Mustela frenata oregonensis_ (Merriam) 304
_Mustela frenata munda_ (Bangs) 309
_Mustela frenata xanthogenys_ Gray 315
_Mustela frenata nigriauris_ Hall 319
_Mustela frenata latirostra_ Hall 323
_Mustela frenata pulchra_ Hall 328
_Mustela frenata inyoensis_ Hall 331
_Mustela frenata neomexicana_ (Barber and Cockerell) 333
_Mustela frenata texensis_ Hall 338
_Mustela frenata frenata_ Lichtenstein 341
_Mustela frenata leucoparia_ (Merriam) 347
_Mustela frenata perotae_ Hall 351
_Mustela frenata goldmani_ (Merriam) 355
_Mustela frenata macrophonius_ (Elliot) 360
_Mustela frenata tropicalis_ (Merriam) 363
_Mustela frenata perda_ (Merriam) 366
_Mustela frenata nicaraguae_ Allen 370
_Mustela frenata costaricensis_ Goldman 372
_Mustela frenata panamensis_ Hall 375
_Mustela frenata meridana_ Hollister 379
_Mustela frenata affinis_ Gray 384
_Mustela frenata aureoventris_ Gray 387
_Mustela frenata helleri_ Hall 391
_Mustela frenata agilis_ Tschudi 393
_Mustela frenata macrura_ Taczanowski 398
_Mustela frenata boliviensis_ Hall 402
_Mustela frenata gracilis_ (Brown) 404
Subgenus =Grammogale= Cabrera
_Mustela africana_ 406
_Mustela africana africana_ Desmarest 409
_Mustela africana stolzmanni_ Taczanowski 413
Subgenus =Putorius= Cuvier
(Black-footed Ferret--not treated in present work)
_Mustela nigripes_ (Audubon and Bachman)
Subgenus =Lutreola= Wagner
(Minks--not treated in present work)
_Mustela vison_
_Mustela vison vison_ Schreber
_Mustela vison mink_ Peale and Beauvois
_Mustela vison lutensis_ (Bangs)
_Mustela vison evergladensis_ Hamilton
_Mustela vison vulgivaga_ (Bangs)
_Mustela vison letifera_ Hollister
_Mustela vison lacustris_ (Preble)
_Mustela vison energumenos_ (Bangs)
_Mustela vison evagor_ Hall
_Mustela vison aestuarina_ Grinnell
_Mustela vison nesolestes_ (Heller)
_Mustela vison melampelus_ (Elliot)
_Mustela vison ingens_ (Osgood)
_Mustela macrodon_ (Prentiss)
ARTIFICIAL KEY TO AMERICAN SPECIES OF THE GENUS MUSTELA
PAGE
A Length of upper tooth-rows less than 20 mm. in males and
17.8 mm. in females.
B Postglenoid length of skull more than 47 per cent of
condylobasal length.
C Tail without a black pencil and with at most a few
black hairs at extreme tip; in both sexes mastoid
breadth ordinarily exceeds breadth of braincase,
_Mustela rixosa_, least weasel, p. 168
C' Tail with a black pencil; in females mastoid breadth
ordinarily exceeded by breadth of braincase,
_Mustela erminea_, ermine, p. 87
B' Postglenoid length of skull less than 47 per cent of
condylobasal length.
D Tail with distinct black tip; midventral line white,
yellowish, orange, not same color as upper parts; p2
present; thenar pad on forefoot absent,
_Mustela frenata_, long-tailed weasel, p. 193
D' Tail without black tip; midventral line same color
as upper parts; p2 absent; thenar pad on forefoot
present,
_Mustela africana_, tropical weasel, p. 406
A' Length of upper tooth-rows more than 20 mm. in males and
17.8 mm. in females.
E Abdomen all white; face with blackish mask; m1 lacking
even a trace of a metaconid; distance between upper
canines more than width of basioccipital as measured
between foramina situated midway along medial sides of
tympanic bullae,
_Mustela nigripes_, black-footed ferret.
E' Abdomen dark brown, like back; face uniformly brown
without blackish mask; m1 with incipient metaconid;
distance between upper canines less than width of
basioccipital as measured between foramina situated
midway along medial sides of tympanic bullae,
_Mustela vison_, mink, American mink.
DIAGNOSIS OF THE GENUS
Genus =Mustela= Linnaeus
Weasels, Ferrets, Polecats, Minks
_Genotype._--_Mustela erminea_ Linnaeus.
_Diagnosis._--Legs short; body relatively long; adults 190 mm. to 700
mm. in total length; skull ranging in basilar length from 16 to 70 mm.;
facial angle slight; tympanic bullae greatly inflated (moderately in
_Lutreola_), cancellous, and with paroccipital processes closely
appressed to bullae; palate behind upper molars; dental formula:
I 3 C 1 P 2-3 M 1
-, -; -, -; -, ---; -, -; inner moiety of M1 larger than outer; P4
i 3 c 1 p 3-2 m 2
with simple deuterocone; in m1 inner moiety of M1 larger than outer; P4
with simple deuterocone; in m1 trigonid longer than talonid, metaconid
absent (incipiently developed in _Lutreola_), and talonid trenchant.
For many years prior to 1911, the name _Mustela_ was applied to
martens, and _Putorius_ was regarded as the first available generic
name for the weasels. In 1911 Thomas (1911:139) showed that _M.
erminea_ (_Mustela_ of Gesner) by tautonymy was the type of _Mustela_
and subsequently the generic name _Mustela_ has been used for the true
weasels which include the American weasels to which we now apply the
specific names _erminea_, _rixosa_ and _frenata_. The mink, _Mustela
(Lutreola) vison_, and the black-footed ferret, _Mustela (Putorius)
nigripes_, since 1911 also have been referred by most American authors
to the genus _Mustela_, the names _Lutreola_ and _Putorius_ being
regarded by these authors as having no more than subgeneric status.
European writers, on the other hand, accord greater taxonomic weight to
the zoölogical differences between ferrets and weasels and, therefore,
accord full generic rank to _Putorius_. Consequently, for the
black-footed ferret, Europeans today write _Putorius nigripes_ and
Americans write _Mustela nigripes_. For the same reasons, the name of
the mink is written by some European zoölogists _Lutreola vison_ and by
American zoölogists _Mustela vison_.
EXPLANATION OF SYSTEMATIC TREATMENT
For each full species there will be found under the account of it the
following information: Type, statement of geographic range, selected
characters for ready recognition, other characters of the species, a
summary of geographic variation, and information on habits, in the
order mentioned.
For each subspecies, information is presented in the following order:
earliest available zoölogical name, synonyms, type, geographic range,
zoölogical characters for ready recognition, description (mentioning
size, certain external features including color, the skull and teeth)
historical material when warranted, remarks which may elaborate on
points made in preceding paragraphs, and other information thought to
be useful, and finally a list of specimens examined.
In explanation of certain of these categories it should be said that in
the synonymy no attempt is made to list every published reference to
the subspecies concerned. It is aimed, however, to include at least one
citation to each name-combination that has been applied, to the
subspecies concerned, along with other especially important references.
Mere records of occurrence are not regarded as especially important and
citations to them ordinarily are omitted in the synonymy. No comma is
placed between the zoölogical name and the name of the author who
coined and first used the name in accordance with the rules of
zoölogical nomenclature. Otherwise a comma is interposed between the
zoölogical name and the name of the user (author). When the accepted
(earliest available) name of a subspecies at the head of any one of the
following accounts is combined with a generic name different from that
with which it originally was placed, the authority for the name is set
in parentheses. The same rule is followed with the name of a full
species when it is written without any subspecific name following.
Parentheses in such situations, therefore, denote that for the terminal
part of the scientific name there has been a change in generic name
with which the terminal part of the scientific name is here associated.
In the paragraph headed "characters for ready recognition," only a few
characters, namely, those regarded as most useful for identification
when the student has limited time, are mentioned. Other features useful
for distinguishing the kind of animal in question from its near
relatives are to be found in the description and comparisons.
In the description, external measurements, unless otherwise indicated,
are those recorded by the collector on the label attached to the skin.
Total length is the distance from the tip of the pad on the nose to the
tip of the fleshy part of the tail when the relaxed animal is laid out
straight, not stretched. This measurement does not include the hairs
that project beyond the end of the fleshy part of the tail. Length of
tail is the distance from the base of the tail, when it is bent at
right angles to the long axis of the body, to the tip of the fleshy
part of the tail excluding the hairs that project beyond the fleshy
part of the tail. Length of tail and length of tail-vertebrae are
synonymous. Length of hind foot is measured from the proximal end of
the calcaneum to the tip of the longest claw.
Capitalized color terms, unless otherwise indicated, refer to Ridgway's
(1912) _Color Standards and Color Nomenclature_. Some use is made of
color terms taken from Oberthür and Dauthenay (1905) because those
authors show a much larger number of shades between dark brown and
black than does Ridgway (1912). The colors of the upper parts of most
weasels are some shade or other of dark brown. Color terms that do not
have the initial letter capitalized do not refer to any one standard
and consequently are used in a general sense.
Relative extents of the color of the upper parts and underparts are
computed from measurements of the circumference of the body at the
place where the color of the underparts is narrowest. Ordinarily this
place is in the lumbar region rather than in the thoracic region.
An explanation of how cranial measurements were taken is given on page
417. In designating teeth, capital letters are used for teeth in the
upper jaw and lower case letters are used for teeth in the lower jaw.
For example: I2 denotes the second incisor tooth in the upper jaw and
i2 denotes the second incisor tooth in the lower jaw; C1 and c1 refer
to the canine tooth of the upper jaw and lower jaw, respectively; P3
and p3 refer to the third premolar of the upper jaw and lower jaw,
respectively, bearing in mind that the first (anterior) premolar is
absent in the lower jaw and upper jaw of weasels (see fig. 31 on page
416), as also, in some kinds of weasels, is the second premolar; M1 and
m1 refer to the first molar of the upper jaw and lower jaw
respectively.
In describing the skull and teeth the two sexes are treated separately
because differences in shape as well as size are the rule. Unless
otherwise indicated, the skulls on which descriptions are based are of
adults. Weights of skulls include the weight of the lower jaws. In
general, every second subspecies is described. For a subspecies
geographically next adjacent to the one described, only the
differences between the two are enumerated. This method of description
indicates also likenesses and is more economical of words than some
other methods of description. Also, by use of this method, cross
reference is reduced to one other subspecies. Following this formal
description, there is a comparison of the cranial and dental characters
with those of geographically adjacent subspecies.
In the paragraph headed "Remarks" the two words "character" and
"structure" frequently appear. The word structure here is used to mean
some part of an animal, as for example, a hair, a muscle, a bone, or an
internal organ. A structure is not a system, as for example, the
digestive system or osseous system. A character is some weight, linear
dimension, volume, shape, color, or other perceptible attribute of a
structure, of a system, or of an entire organism.
In recording the localities of capture of specimens examined, effort
has been made to be exactly as precise as the locality data on the
labels of the specimens permit. The word "County" is written out in
full when the name of the county is written on the label of each
specimen listed from that county. When one specimen, or more, here
assigned to a given county lacks the name of the county on the label,
then the abbreviation "_Co_." is used. The surprising frequency with
which the same place name is repeated in a given state or province
makes it desirable for the collector to write the name of the county,
or corresponding minor political subdivision, on labels of study
specimens at the time they are prepared.
SYSTEMATIC ACCOUNTS OF SPECIES AND SUBSPECIES
=MUSTELA ERMINEA= Linnaeus
Ermine
(Synonymy under subspecies)
_Type._--_Mustela erminea_ Linnaeus, Systema Naturae, 10th ed., p.
46, 1758.
_Range._--From the British Isles and Atlantic Coast of Europe
across Eurasia and North America including Greenland, from the
northernmost land, south, in North America, to the lower margin of
the Canadian Life-zone; geographically south to Connecticut, New
York, Pennsylvania, northeastern Ohio, southern Michigan,
Wisconsin, northern Iowa, Minnesota, North Dakota, in the Rocky
Mountains to northern New Mexico, in the Sierra Nevada to Mono
County, California, and on the Pacific Coast to the Golden Gate.
_Characters for ready recognition._--Differs from _Mustela rixosa_ in
presence of black pencil on tail, tail-vertebrae more than a fourth of
length of head and body, and in regions where the two species occur
together, basilar length of skull more than 32.5 in males and more than
31.0 in females; from _Mustela frenata_, in regions where the two
species occur together, by tail less than 44 per cent of length of head
and body and by postglenoidal length of skull more than 46 per cent of
condylobasal length in males and more than 48 per cent in females.
_Characters of the species._--Size medium to small (total length 225 to
340 mm. in males and 190 to 290 mm. in females); tail 30 to 45 per cent
of length of head and body, with distinct black pencil; caudal
vertebrae 16 to 19; skull with long braincase and short precranial
portion; postglenoidal length, when expressed as a percentage of the
condylobasal length, more than 48 in females and ordinarily more than
46 in males; upper parts brown; underparts whitish, ordinarily
continuous from chin to inguinal region but in subspecies in the humid
region along the Pacific Coast interrupted in some individuals by brown
of upper parts encircling body in the abdominal region. The soles of
the feet in each of the subspecies are densely haired in winter and
have only a relatively small area of the foot-pads exposed in summer,
the intervening areas being well haired even at that season. The
uniformity throughout the species as regards hairiness of the
foot-soles and also the character of the vibrissae makes it unnecessary
to describe these features in the accounts of the subspecies of
_erminea_.
_Geographic variation._--In the Old World 16 or more subspecies are
currently recognized and there are 20 in North America. The features in
which geographic variation is especially prominent are: First, size,
as expressed by external measurements and weight, second, color
pattern, depending on the extent, in relation to one another, of the
dark-colored upper parts and light-colored underparts, and third,
breadth and depth of the rostral region of the skull. Except in size,
the variation in the skull is less than in _M. frenata_. Likewise in
tone and shade of upper parts and hue or tint of underparts, _erminea_
is less variable than _frenata_ and has the face all of one color
without the contrasting color-pattern of the face and head seen in many
subspecies of _frenata_. _M. erminea_ exceeds _frenata_ as regards
variation of the size of the area occupied by the light-colored
underparts. At one extreme is the subspecies _arctica_ in which the
area of the light color extends well up on the sides of the body, down
the insides of the legs, over the feet and far out on the lower side of
the tail whereas at the other extreme are the races _streatori_ and
_olympica_ in which the light-colored underparts are restricted to two
areas, one on the chin, throat and chest, and the other on the inguinal
region. These areas may or may not be connected by a thin line of white
color along the midline of the underparts. In size of animal, _erminea_
probably exhibits the maximum variation among American species of
weasels; an average-sized male of the race _arctica_ weighs 4 times as
much as one of the race _muricus_, and in the species _frenata_ I doubt
that the difference is quite as great between individuals of the
smallest race, _effera_, on the one hand, and either of the largest
races, _texensis_ or _macrophonius_, on the other hand although actual
weights are not available for these races of _frenata_. As elsewhere
indicated, the small-sized individuals of _M. erminea_ are of the
southern races and the large-sized individuals are of the northern
races. This decrease in size southward occurs both in Asia and in
America.
_Natural history._--habitat and numbers.--Along the International
Boundary east of the Turtle Mountains, Soper (1946:136) found this
species present only in timbered areas and absent from many untimbered
areas. Of the same species to the westward he comments "so far as I
know at present, there is no evidence to show that any short-tailed
weasels inhabit a broad strip of treeless territory immediately north
of the International Boundary in Canada from southwestern Alberta to
southeastern Saskatchewan." The same author (1942) reports that in the
general area of Wood Buffalo Park, Northwest Territory, south of Great
Slave Lake, the ermine is uncommon on pine-grown sand ridge and rolling
upland and common in lower spruce-aspen parklands, stream-side
coniferous belts, and grassy, semi-wooded swamplands.
Nine ermines per square mile is the number that Soper (1919:46-47)
estimated at Edmonton on the basis of the numbers that he trapped there
in the winters of 1912-13 and 1913-14 and on the basis of the tracks of
remaining ermines. From corresponding data he estimated the population
in the winter of 1913 on the Hay River, north of Jasper Park, to be
nine per square mile. In each of these instances he estimated ten
weasels per square mile but he inclined to the view that one-tenth of
the animals involved in his counts were long-tailed weasels (_Mustela
frenata_). Osgood (1909B:30) and his field companion in the period July
31 to September 3, 1903, took a series of 42 specimens within a radius
of 500 yards of their camp at the head of Seward Creek, Alaska, all
caught in four traps, in one month. Of the 42 specimens, 28 are males
and 14 are females.
Fluctuations of a multiannual nature are marked in this species. Bailey
(1929:156) observes that in Sherburne County, Minnesota, when meadow
mice are abundant for two or three years these weasels become abundant
but that when the mice are scarce the weasels also become scarce.
Manning (1943:56), on Southampton Island, noted "that the maximum and
minimum points of the weasel cycle are much more sharply marked than
those of the fox cycle and the increase and decrease are more rapid."
How far an ermine will travel in a given length of time has seldom been
recorded but Hamilton (1933:293), on March 20, 1932, "followed the
track of a small weasel, presumably a male _cicognanii_, for four miles
in the fresh snow," and Ingles (1942) observed a diminutive ermine of
the subspecies _M. e. muricus_, at Woods Lake, California, 286 yards
from its den.
Behavior
As regards locomotion, Soper (1919:46), in reference to _Mustela
cicognanii_, presumably in Ontario, Canada, writes that in the bounding
gait the hind feet register almost, if not exactly, in the front-foot
impressions, with the right front and hind feet lagging slightly
behind. "The distance normally is about 19 inches, representing a
regular rate of travel. . . . In traversing open spaces they resort to
long, graceful leaps upwards of six feet in length. . . . I measured a
record . . . of 8 feet, 2 inches."
Of _M. e. arctica_, Dice (1921:22) writes that when it runs "the tail
is carried off the ground usually at an angle of about 45 degrees."
Seton (1929 (2):598) states that "At Carberry [Manitoba] I have often
seen this energetic little creature seeking for Mice in the deep, soft
snow. Its actions are much like those of an Otter pursuing salmon.
Sometimes it gallops along a log, or over an icy part of the drift;
then plunges out of sight in a soft place, to reappear many yards
away. . . ."
Little is recorded concerning swimming but on this score Seton (1929
(2):602) does quote J. W. Curran, who in July, 1899, at Lake
Couchiching, Ontario, watched an ermine pursue a chipmunk into the
water and for 100 yards before giving up the chase and wheeling around
and making for shore. In swimming "The Weasel, I think, showed more of
his body, and seemed to exert himself more" than the chipmunk.
As to voice, Dice (1921:22), at Tanana, Alaska, heard the ermine, when
excited, bark somewhat like a mink but not so loud and Seton (1929
(2):606) quotes Manley Hardy to the effect that the species has a
purring note.
Sense of smell was used by an _M. e. muricus_ that Dixon (1931:72)
watched as the ermine followed a three-fourths-grown pika. Concerning
the ermine at Carberry, Manitoba, Seton (1929 (2):598-599) writes that
"The smell of blood must be as far-reaching as it is attractive to
these sanguinary little creatures. I have frequently hung new-killed
Rabbits and partridges temporarily in trees, and, after an absence, in
some cases of a few minutes only, have found an Ermine mauling the
game, though there was no sign of such a visitor when the cache was
made."
Enemies