measuring the amount of individual and age variation in several
features. For instance, the material is sufficient to show that
external measurements of subadults and those that fall in the upper
part of the category designated as "young" may be included with the
measurements of adults, because the mentioned measurements are not
appreciably greater in adults. The series of skulls, although not
providing more than six of any one age, shows the range of variation in
size and proportion of certain parts and enables the student the better
to evaluate cranial characters of nearby races known from only a few
specimens. For example, not one of the twenty skulls of males from
Brownsville and immediate vicinity is as large as either of the two
specimens of _texensis_ from Kerr County.
The white facial markings vary much in size and shape. In the series of
thirty-four skins from Brownsville the broad white bands in front of
the ears are confluent with the white patch between the eyes on both
sides in three specimens and on one side only in six other specimens.
These bands are confluent with the color of the underparts in all but
two specimens. In one specimen the connection is lacking on both sides
and in the other on one side only. A white patch between the ears is
present in two specimens. The dark spot at each angle of the mouth is
absent on both sides in eleven specimens and absent on one side only in
ten others.
In six other specimens from parts of Texas north of Brownsville, the
broad white bands in front of the ears are confluent with the white
patch between the eyes on both sides in one specimen. A white spot
between the ears is present in one specimen. The dark spot at each
angle of the mouth is absent on both sides in six specimens and on one
side only in three other specimens.
In eleven specimens from México, the broad white bands in front of the
ears are confluent with the white spot between the eyes on both sides
in two specimens and on one side only in one other specimen. The white
spot between the ears is present in one specimen. The dark spot at each
angle of the mouth is absent on both sides, in six specimens, and on
one side only in one other specimen.
Thus, in 51 specimens the broad bands (one in front of each ear) are
confluent with the white patch between the eyes in nineteen out of 100
instances, and not with the color of the underparts in three instances.
A white spot between the ears is present in four specimens. The dark
spot at each angle of the mouth is present 47 out of a possible 98
times.
Four juvenal specimens from Brownsville, Texas, with their dates of
capture and probable age, are as follows: no. 58574, [F], three weeks
old, taken on February 15; no. 17318/24239, [M], four weeks old, taken
on March 16; no. 45899, [F], forty days old, taken on May 21; no.
21778/36481, [M], thirty days old, taken on October 20. In the order
given, the dates of birth of these four juveniles would be
approximately as follows: January 25, February 15, April 1, and
September 20. The dates of birth of other specimens less than three
months old as judged by the stage of development of the skull, and
reckoning backward from the dates of capture, are as follows: April 1,
April 30, May 25, October 12, and December 21. Thus, young appear to be
brought forth at Brownsville, Texas, in the fall, winter and spring,
that is to say from the latter part of September until the latter part
of May.
_Mustela frenata frenata_ is either free of the parasites that infest
the frontal sinuses of most weasels, or withstands their presence
remarkably well, for only one skull shows a definite pathological
condition of the frontal sinuses.
Allen (1896:74) quotes H. P. Attwater, with respect to this species in
Bexar County, Texas, as follows: "Not common, but occasionally met
within the chaparral and cactus lands, where Wood Rats, Rabbits and
Quail abound. They were frequently met with around San Antonio during
the great 'Tramp Rat' [= _Sigmodon hispidus texianus_, see Bailey
(1905:116)] invasion of 1889-90."
_Specimens examined._--Total number, 63, arranged by counties, and
in México by states, from north to south. Unless otherwise
indicated specimens are in the collection of the United States
National Museum.
=Texas.= _Bexar County_: San Antonio, 2 (1[2]). _Goliad County_:
Charco, 1. _Nueces County_: Corpus Christi, 1[2]. _San Diego
County_ (not found), 1. _Hidalgo County_: La Hacienda, 1. _Duval
County_: San Diego, 2[7]. _County_ in question: Lower Rio Grande,
1. _Cameron County_: Brownsville, 34 (3[2], 4[1], 3[93], 2[75],
1[59], 1[60], 1[4]); no locality more definite than county, 2.
=Nuevo León.= Río Ramis, 20 mi. NW Montemorelos, 1[90].
=Tamaulipas.= Matamoros, 6; Miquihuana (now in Nuevo León), 1[75].
=San Luis Potosí.= Alvarez, 1[75].
=México=: Region montagneuse des environs de Toluca, Nevada
Toluca, 3200 M., 1[84]
=Distrito Federal.= City of México, 2 (1[4]); Tlalpam, 2. No
locality more definite than México, 4 (1[4], 3[7]).
=Mustela frenata leucoparia= (Merriam)
Long-tailed Weasel
Plates 1, 24, 25, 26, 29, 30, 36, 37 and 38
_Putorius frenatus leucoparia_ Merriam, N. Amer. Fauna, 11:28, June
30, 1896.
_Putorius brasiliensis frenatus_, Allen, Bull. Amer. Mus. Nat.
Hist., 2:165, October 21, 1889.
_Putorius frenatus frenatus_, Allen, Bull. Amer. Mus. Nat. Hist.,
22:259, July 25, 1906.
_Mustela frenata leucoparia_, Miller, U. S. Nat. Mus. Bull.,
79:100, December 31, 1912; Hall, Carnegie Instit. Washington
Publ. 473:108, November 20, 1936.
_Type._--Male, adult, skull and skin; no. 34914/47179, U. S. Nat.
Mus., Biol. Surv. Coll.; Pátzcuaro, Michoacán, México; July 27,
1892; obtained by E. W. Nelson; original no. 2960.
The skull (plates 29 and 30) lacks most of the braincase; a
fragment, consisting of the supraoccipital and the coalesced
frontals and parietals remains. The rostrum, left zygomatic arch,
palate, left pterygoid, left glenoid fossa and right postorbital
process are intact. The teeth all are present and entire. The
lower jaw lacks the right coronoid process and the lateral part of
the articular condyle. The skin is well made and in good
condition. It differs from an adult male topotype (36855, U. S.
Nat. Mus.) and other referred specimens in having: the black of
the head extended farther posteriorly on the neck, the maximum
amount of white on the head, and a white stripe 50 mm. long
extending down the middle of the nape from a point between the
ears more than half way to the shoulders.
_Range._--Sonoran and Transition life-zones of mountains west of
México (city) in Michoacán and Nayarit. See figure 29 on page 221.
_Characters for ready recognition._--Differs from _M. f. goldmani_
in least width of color of underparts more than 47 per cent of
greatest width of color of upper parts, hind feet colored like
underparts rather than like upper parts; postorbital constriction
less than, rather than more than, combined length of upper
premolars; from _M. f. macrophonius_ by same details of coloration
as from _goldmani_ and by ventrally concave rather than ventrally
convex pretympanic part of squamosal; from _M. f. perotae_ by
least width of color of underparts more than 40 per cent of
greatest width of color up upper parts; height of tympanic bulla
more than three-fifths distance from its anterior margin to
foramen ovale; from _M. f. frenata_ by white facial markings that
cover half of surface of head in front of ears, by extension of
black of head onto neck halfway to shoulders and by narrower (less
than 7.8) tympanic bullae; from _M. f. neomexicana_ by Argus Brown
rather than Buckthorn Brown color of upper parts and distance from
anterior margin of tympanic bulla to foramen ovale more, rather
than less, than four-fifths of height of tympanic bulla.
_Description._--_Size._--Male: Two adults and one young from Los
Reyes and Pátzcuaro, Michoacán, yield average and extreme
measurements as follows: Total length, 514 (510-523); length of
tail, 206 (196-215); length of hind foot, 55 (52-58). Tail
averages 67 per cent as long as head and body. Length of hind foot
more than basal length.
Female: One adult from Artenkiki, Jalisco, and one subadult from
Pátzcuaro, Michoacán, measure, respectively, as follows: Total
length, 412, 400; length of tail, 159, 159; length of hind foot,
41, 42. Tail averages 64 per cent as long as head and body. Length
of hind foot equal to or greater than basal length.
The average differences in external measurements of the two sexes
are: Total length, 108; length of tail, 47; length of hind foot,
13.
_Mustela frenata leucoparia_ has a greater total length and length
of tail than either _M. f. frenata_ or _goldmani_. The hind foot
is longer than that of _frenata_ and approximately the same as in
_goldmani_. Relative to the body length, the tail averages longer
than that of _goldmani_ and shorter than that of _frenata_.
_Externals._--As described in _Mustela frenata frenata_.
_Color._--Broad white bands on sides of head, extending
anterodorsally anterior to each ear, confluent with white spot
between eyes and with color of underparts; posterior third of each
upper lip white; remainder of sides and top of head, and neck
posteriorly to point halfway to shoulders from ears, black; no
dark spots at angles of mouth; tip of tail black; remainder of
upper parts Argus Brown; chin white and sometimes also chest, neck
and medial sides of hind legs; remainder of underparts near (16´)
Ochraceous-Buff (near (_a_) Ochraceous-Buff in juvenal female),
which color extends distally over all of each foreleg (except its
lateral face proximally from about middle of forearm) and on
medial side of hind leg and over most of upper side of each foot.
Least width of color of underparts averaging, in eight specimens,
54 (extremes 44-61) per cent of greatest width of color of upper
parts; black tip of tail averaging, in four males, 52 (extremes
38-78) mm. long, thus averaging 25 per cent of length of
tail-vertebrae.
As compared with _M. f. frenata_ and _goldmani_: white facial
markings more extensive; color of underparts less restricted and
more extended on legs; black tip of tail relatively of about same
extent as in _frenata_ and thus much less than in _goldmani_;
black color of head extending farther posteriorly than in
_frenata_ but not so far as in _goldmani_.
_Skull and teeth._--Male (adult): See measurements and plates
24-26, 29, 30. As described in _Mustela frenata frenata_ except
that: Weight (no. 128972) 6.3 grams; basilar length, 51.2;
interorbital breadth less than distance between foramen opticum
and anterior margin of tympanic bulla; anterior margin of tympanic
bulla as far posterior to foramen ovale as width of 4 or 5 upper
incisors; height of tympanic bulla more or less than (about equal
to) distance from its anterior margin to foramen ovale; anterior
margin of masseteric fossa anywhere from slightly anterior, to
slightly posterior, to m2.
Female (based on no. 26153): See measurements and plates 37-39. As
described in _Mustela frenata frenata_ except that: Weight, 3.6
grams; basilar length, 44.5; zygomatic breadth less than distance
between condylar foramen and M1, or than between anterior palatine
foramen and anterior margin of tympanic bulla; tympanic bulla as
far posterior to foramen ovale as width of 4 or 5 upper incisors;
height of tympanic bulla not more than distance from its anterior
margin to foramen ovale; length of tympanic bulla more than length
of lower molar and premolar tooth-row or than length of rostrum.
The skull of the female is 43 per cent lighter than that of the
male.
Comparison of the skull with those of _M. f. perotae_, _goldmani_ and
_neomexicana_ has been made in the accounts of those subspecies. As
compared with that of _frenata_ the main difference is the less
inflated tympanic bulla, the height of which is approximately equal to,
rather than decidedly more than, distance from its anterior margin to
foramen ovale.
_Remarks._--The first specimen known to have been preserved is the
alcoholic in the British Museum of Natural History, taken in September,
1891, on the Río Santiago in Jalisco, by D. A. C. Buller. The other
known specimens of this white-faced weasel are divided between the
American Museum and the United States National Museum. The two referred
specimens from Jalisco were the last of several helpful ones collected
in México and Central America by J. H. Batty, and these two were taken
less than three months before Batty's tragic death in Chiapas (see
Allen, J. A., 1906:191). The five specimens from Michoacán were taken
by Nelson or Nelson and Goldman together. Merriam had only three of
these when he named the subspecies and remarked (1896:29) that "This
form is the poorest subspecies described in the present paper."
Although the form is not strongly marked, the two additional specimens
from Michoacán and better comparative material than Merriam had confirm
several of the differential characters ascribed to it by him and
indicate the existence of still other characters.
_M. f. leucoparia_ occurs in the Sonoran and Transition life-zones. No.
27258 from Los Masos, and no. 26153 from Artenkiki (see specimens
examined for other spellings) approach true _frenata_ in coloration.
Each of these specimens has a few white hairs between the ears and the
white patch between the eyes is confluent on one side only with the
lateral white bands on the side of the head. No. 27258 from Los Masos
has a dark spot at each angle of the mouth. The 7 other specimens are
relatively uniform in coloration. Each has the white spot between the
eyes confluent on both sides with the extensive white areas on each
side of the face. None has a dark spot at either angle of the mouth. Of
these 7 specimens, the type specimen and three others have white hairs
forming a median line between the ears and a fifth specimen has a white
spot behind each ear.
_M. f. leucoparia_ is most like _M. f. frenata_. Unlike _frenata_,
_leucoparia_ has tympanic bullae that are less inflated, narrower and
less projected, at their anterior margins, from the cranium. In these
characters _leucoparia_ is intermediate between _M. f. frenata_ and _M.
f. goldmani_. The latter subspecies has the least inflated, narrowest
and least projecting tympanic bullae of the three. The black color of
the head extends, on the average, farther posteriorly than in _M. f.
frenata_ but not so far as in _M. f. goldmani_. The general color, too,
is intermediate between that of _M. f. frenata_ and that of the much
darker _M. f. goldmani_. The white facial markings are more extensive
than in either _M. f. frenata_ or _M. f. goldmani_. This applies to
both the white area between the eyes and the one on each side of the
head between the ear and eye. _M. f. neomexicana_, whose range possibly
meets that of _M. f. leucoparia_, also has more extensive white facial
markings than _M. f. frenata_ but less extensive markings than _M. f.
leucoparia_.
On the basis of skulls alone, specimens of _frenata_ from Tlalpam and
those of _leucoparia_ from Los Reyes can hardly be distinguished. This
fact, and the circumstance that the specimens from the northern part of
the range of _leucoparia_ closely resemble _frenata_ in color,
constitute sufficient evidence for regarding the two as only
subspecifically distinct. The female, no. 26153 from Artenkiki, as
mentioned above, approaches true _frenata_ in coloration. On this
account it is not to be regarded as typical and it was because no other
skulls of adult females were available that this one was used for
comparison with females of allied races.
_M. f. leucoparia_ is, then, a subspecies of the large, temperate-zone
group and is unique in possessing the maximum extent of white facial
markings.
None of the seven skulls shows signs of having had the frontal sinuses
infested with parasites.
_Specimens examined._--Total number, 8, all from México.
Localities are listed by states from north to south. Specimens
from Michoacán are in the United States National Museum; one from
Río Santiago is in the British Museum of Natural History; all
others are in the American Museum of Natural History.
=Nayarit.= Tepic, 1.
=Jalisco.= Río Santiago, 1; Los Masos, 1; "Artenkiki" (J. A.
Allen, 1906, p. 238, writes "Artenkikil" and, on p. 259,
"Artenkiki."), 1.
=Michoacán.= Zamora, 1; Los Reyes, 1; Pátzcuaro, 3.
=Mustela frenata perotae= Hall
Long-tailed Weasel
Plates 36, 37 and 38
_Mustela frenata perotae_ Hall, Carnegie Instit. Washington Publ.
473:100, November 20, 1936.
_Putorius frenatus_, Merriam, N. Amer. Fauna, 11: pl. 3, fig. 2,
June 30, 1896.
_Type._--Female, adult, skull and skin; no. 54278, U. S. Nat.
Mus., Biol. Surv. Coll.; 12,500 feet, Cofre de Perote, Veracruz,
México; May 26, 1893; obtained by E. W. Nelson; original no. 4864.
The skull (plates, 37-39) lacks the right zygomatic arch. Left p2
is missing. The skin is fairly well made and in good condition
except that the extreme tip of the tail has been broken off and
there are two holes in the right hind leg. The underparts show the
beginning of a spring molt.
_Range._--From 7500 (?) feet (Perote) to 13,500 feet
(Popocatépetl), Upper Sonoran, Transition and Boreal life-zones of
mountains along Puebla-México boundary, eastward to western
central Veracruz and south into Oaxaca. See figure 29 on page 221.
_Characters for ready recognition._--Differs from _M. f. frenata_,
its nearest relative, in extension from head of blackish onto
anterior fourth of neck; restriction of color of underparts (least
width of same less than 37 per cent of greatest width of color of
upper parts), height of tympanic bulla less than distance from its
anterior margin to foramen ovale; from _M. f. macrophonius_ and
_M. f. goldmani_ in presence of, rather than absence of, color of
underparts on hind feet; upper parts (black) Brussels Brown rather
than Argus Brown or darker; from _M. f. tropicalis_ in larger size
(adult female with total length more than 400, basilar length more
than 40, weight of skull more than 3 grams); postorbital breadth
less than combined length of upper premolars; m1 more than 5.4
long; from _M. f. leucoparia_ in white facial markings so
restricted that spot between eyes is not confluent with white
stripe in front of ear, or, if so, narrowly (less than 4 wide)
confluent; color of upper parts extending onto antipalmar face of
forefoot, least width of color of underparts not more than 40 per
cent of greatest width of color of upper parts; height of tympanic
bulla not more than three-fifths distance from its anterior margin
to foramen ovale.
_Description._--_Size._--Male: A nontypical specimen from Cerro
San Felipe, Oaxaca, measures: Total length, 500; length of tail,
205; length of hind foot, 52.
Female: The type specimen, measures: Total length, 418; length of
tail, 160; length of hind foot, 45.
In this male the tail is 70, and in the female, 62 per cent as
long as the head and body. In each the hind foot is longer than
the basal length.
The differences in external measurements between these two
specimens, representing the two sexes, are: Total length, 82;
length of tail, 45; length of hind foot, 7.
_Externals._--As described in _Mustela frenata frenata_.
_Color_ (based on type specimen).--Color and color pattern as
described in _Mustela frenata frenata_ except that: blackish of
sides and top of head extends one-fourth of way back to shoulders
from ears; throat and breast as well as chin white; remainder of
underparts near (16´ _c_) Ochraceous-Buff; least width of color of
underparts equals 36 per cent of greatest width of color of upper
parts; black tip of tail equal to 28 per cent of length of
tail-vertebrae.
_Skull and teeth._--Male (based on a referred specimen from Cerro
San Felipe which certainly is nontypical): See measurements. As
described in _Mustela frenata frenata_ except that: Weight, 4.9
grams; basilar length, 49.2; postorbital breadth more than
distance between posterior borders of P4 and P2; tympanic bulla as
far posterior to foramen ovale as width of 5 upper incisors;
height of tympanic bulla less than distance from its anterior
margin to foramen ovale; zygomatic breadth less than distance
between condylar foramen and M1 or than between anterior palatine
foramen and anterior margin of tympanic bulla.
Female (based on type specimen, an adult): See measurements and
plates 37-39. As described in _Mustela frenata frenata_ except
that: Weight 3.4 grams; basilar length, 43.5; zygomatic breadth
less than distance between condylar foramen and M1 or than between
anterior palatine foramen and anterior margin of tympanic bulla;
postorbital breadth less than width of basioccipital measured from
medial margin of one foramen lacerum posterior to its opposite;
tympanic bulla as far posterior to foramen ovale as width of 5 or
6 upper incisors; height of tympanic bulla one-half to
three-fifths distance from its anterior margin to foramen ovale;
length of tympanic bulla more than length of lower molar and
premolar tooth-row and longer than rostrum.
The skull of the female is 33 per cent lighter than that of the
nontypical (and smaller than average) male from Cerro San Felipe.
Comparison of the skull with that of _M. f. tropicalis_ is made in the
account of that subspecies. Compared with the skull of _M. f._
_macrophonius_, that of the female of _perotae_ is more flattened, has
the longitudinal dorsal outline distinctly concave rather than flat
just behind the postorbital processes, and much wider tympanic bullae.
Accordingly, the basioccipital is slightly narrower in _perotae_. The
more marked postorbital constriction of the type specimen of _perotae_
possibly is due to its relatively greater age. As compared with the
skull of _M. f. leucoparia_, that of the female of _perotae_ has less
inflated tympanic bullae, the height of each being half as great as
distance from its anterior margin to foramen ovale, whereas, in
_leucoparia_ (as represented by no. 26153) the two distances are equal.
As compared with that of _M. f. frenata_, the skull of the female of
_perotae_ differs mainly in the lesser inflation of the tympanic bullae
and their relative position. The height of each bulla is in _perotae_
only half as much as, but in _frenata_ more than, the distance from its
anterior margin to foramen ovale. The anterior margin of the bulla is
much less projected from the floor of the braincase in _perotae_. The
squamosal anterior to each bulla is convex ventrally in _perotae_ but
flat or concave ventrally in _frenata_.
_Remarks._--The type specimen and a juvenal female from the town of
Perote were taken in the spring of 1893 by E. W. Nelson. Of these two,
the type specimen was mentioned and figured by Merriam (1898:30, fig.
16 [= fig. 15], pl. 3, fig. 2) as _Putorius frenatus_. The referred
nontypical specimen from Cerro San Felipe, Oaxaca, was referred by
Merriam (op. cit.:29) to _Putorius frenatus goldmani_ with the comment
that it was intermediate ". . . both in coloration and cranial
characters, between typical _frenatus_ and _goldmani_;. . . ." No other
published references to this subspecies, or specimens of it, have been
seen. In 1941 and 1942, W. B. Davis and associates took four specimens
along the boundary between the states of Puebla and México.
Although the specimen from Cerro San Felipe, Oaxaca, is referred to
_Mustela frenata perotae_, to the description of which it answers best,
that specimen, on account of its structural characters and geographic
position relative to adjacent races, is in reality an intergrade
between several of the adjacent races. Some of its intermediate
characters are pointed out in the discussion of _M. f. goldmani_. In
the specimens from 45 and 55 kilometers ESE of México (city) the black
color of the top of the head does not extend so far behind the ears as
in the holotype of _M. f. perotae_ and in this feature the two
specimens show intergradation between the two subspecies, _perotae_ and
_frenata_.
The type specimen taken on May 26, is acquiring new hair on the belly
and lower sides which appears to be the result of a normal molt.