Part 22

=Minnesota.= _Roseau County_: Cedarbend, 2[14]; Grimstad, 1[14]; America, 2 (1[14], 1[74]); Malung, 1[74]; Norland, 1[41]; Falun, 3 (1[14], 1[74], 1[41]); Palmville, 1[41]; Spruce, 1[74]; Stokes, 1[74]. No locality more definite than Marshall County, 1[14]. _Clay County_: Moorhead, 1[36]. _Winona County_: "near" Whitman, 1[34]; Altura, 1[98]; Crystal Springs, 1[98].

=Montana.= Sun River Valley, 1; Wibaux in Wibaux County, 1.

=North Dakota.= _Walsh County_: Grafton, 15 (3[60], 1[93], 5[2], 2[14], 1[74], 1[1], 1[76]). _McHenry County_: 4 and 4-1/2 mi. N Upham, 2. _Wells County_: 1[36]. _Morton County_: Mandan, 1[60].

=Ontario.= Algoma Dist: Tatnall, near Oba, 1[86]. Moose Factory, 1[75].

=Quebec.= Island S of Comb Hills, James Bay, 1[9]. _Saguenay County_: Natashkwan, 1.

=Saskatchewan.= Osler, 1[75]; "near Regina," 1[77]; Dollard, 2[31]; Shaunavon (and "near" and 1 mi. NE), 9[77]; Klintowel P. O. (about 15 mi. N of Eastend), 1[77]; Eastend and "near" Eastend, 2[77].

=Mustela rixosa allegheniensis= (Rhoads)

Least Weasel

Plates 14, 15 and 41

_Putorius allegheniensis_ Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 1900:751, March 25, 1901.

_Putorius rixosus allegheniensis_, Cory, Mamm. Illinois and Wisconsin, p. 378, 1912.

_Mustela allegheniensis_, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912.

_Mustela rixosa allegheniensis_, Swenk, Journ. Mamm., 7:328, November 23, 1926.

_Type._--Probably male adult, skin and skull, no. 6195, Acad. Nat. Sci. Philadelphia; near Beallsville, Washington Co., Pa.; about 1885 or 1886; obtained by Robert Hawkins.

Type not seen by me.

_Range._--Wisconsin, northern Illinois, northern Indiana, Michigan, Ohio, Pennsylvania east to Dauphin County and south in the mountains to northwestern North Carolina. See figure 28 on page 180.

_Characters for ready recognition._--Distinguished from _M. r. rixosa_ by three average differences, namely, darker color, shorter tympanic bullae, and smaller size of males; from _M. r. campestris_ in smaller size: hind foot less than 25 in males and less than 22 in females; in males total length less than 216 and tail averaging less than 34, color averaging darker; from _M. frenata_ and _M. erminea_ of same region by basilar length less than 31, tail less than 45, and lacking black pencil.

_Description._--_Size._--Male: An adult or subadult from Fair Oaks, Pa., a subadult from Finleyville, Pa., and an adult from Huttonsville, W. Va., measure, respectively as follows: Total length, 206, 194, 191 (average 197); length of tail, 37, 32, 28 (32); length of hind foot, 23 in each. An adult from Roanoke, Indiana, weighs 40.6 grams.

Female: Two young from Leasuresville, Pa., and Middle Paxton Twp., Pa., measure, respectively, as follows: Total length, 188, 172; length of tail, 33, 30; length of hind foot, 20.5, 21. An adult from Monroeville, Ohio, weighs 40.5 grams and a young individual from Middle Paxton Twp., Pa., 39.3 grams, and a subadult from Swan Creek Exp. Station, Allegan Co., Mich., weighs 49 grams.

_Color._--Winter pelage either all white, or brown as in summer; upper parts about Raw Umber, or tone 2 of Carbo Brown of pl. 342 of Oberthür and Dauthenay. Underparts white at least on thoracic region; approximately three-fourths of specimens with brown rictal spot at angle of mouth or with this area covered by brown upper parts which extend down on each side and meet on the underparts in about one specimen out of three; upper lips and hind feet ordinarily brown; toes of forefeet ordinarily white (see under remarks for details of color pattern). Least width of color of underparts in the specimens in which the dark color of the upper parts does not encircle the body averages 60 per cent of greatest width of color of upper parts, or including all specimens the percentage is 42.

_Skull_ (based on specimens from Pa. listed in table of cranial measurements, which see and plates 14 and 15).--Basilar length 29.7 and 28.6 in male and 28.0 in female; weights unavailable; otherwise as described in _M. e. richardsonii_. The length of the tympanic bullae seems to be actually less, and less in relation to the basilar length, than in other American subspecies of _M. rixosa_.

_Remarks._--Robert Kennicott's mention in 1859 (p. 245) of what seems to be this subspecies is the earliest reference to it that I can identify in the literature. He used the specific name _pusillus_ and it was not until 1900 that Samuel N. Rhoads proposed the name _Putorius allegheniensis_. Since 1900, several records of occurrence have been published which have made the geographic range of this race better known.

An adequate number of specimens has been gathered only from Ohio and from western Pennsylvania. Many from Ohio are without accurate external measurements taken in the flesh. The majority of the specimens from Pennsylvania owe their preservation to the willingness of local officials, who pay bounties on weasels, to save the skins of _Mustela rixosa_. These specimens ordinarily comprise the skin with locality but because the feet, external measurements in the flesh, and skulls are unavailable, the material is far from adequate and to give an accurate notion of the usual or average cranial characters of _allegheniensis_ in Pennsylvania, skulls from there are especially desirable.

A smaller percentage of the specimens from Ohio than from Pennsylvania have the brown color of the upper parts meeting on the underparts. Also, more of the specimens from Ohio are lighter colored and this suggests intergradation with the subspecies _campestris_ and _rixosa_ to the westward.

From Pennsylvania 23 animals in brown pelage are available. In 5 there is a rictal spot at the angle of the mouth; in 5 the area is white and in 13 the brown color of the upper parts is continuous over the area in question. Only 2 of 23 have the upper lips white. Eight have the color of the upper parts meeting on the venter thus restricting the white of the underparts to the chin, throat, and pectoral region, and 6 of these have a white area in the inguinal region as well. The toes of the forefeet are white in 3 of 4 animals suitable for examination in this regard and the hind feet are marked with white in 3 of the 8 animals which have the hind feet preserved. _Mustela rixosa_ in Pennsylvania parallels the species _Mustela frenata_ in that in this relatively humid area of the northeastern United States the color of the upper parts is darker and the area of the dark-colored upper parts is increased at the expense of the area of the light-colored underparts. Also _Mustela erminea_ in this same region (range of the subspecies _Mustela cicognanii_) shows the same tendency to darker color of upper parts and their extension in area at the expense of the area of the light-colored underparts, or was mentioned above.

It is difficult to account for the seeming absence of the species from New England and all that part of Canada and the United States south of the St. Lawrence River and northeastward from Pennsylvania. The size of females of _M. erminea cicognanii_ in that territory is so little more than in _rixosa_ that the latter possibly cannot successfully compete with the _erminea_ stock which may already occupy the ecologic niche to which _rixosa_ is adapted. It will be remembered that in western North America in territory seemingly climatically suitable for _rixosa_ it occurs no farther southward than the line below which _M. erminea_ has become reduced to a size comparable with that of _M. rixosa_.

Of 41 subadult and adult skulls assigned to this subspecies 24 have obvious lesions in the frontal sinuses evidently resulting from infestation by nematodes. More in detail, none of the specimens from Illinois (3 individuals), Pennsylvania (3 barely subadult), or West Virginia (2) displays lesions. From Wisconsin, Indiana, Virginia and North Carolina there is one specimen each and each specimen displays lesions. From Ohio, 17 of 23 specimens display lesions. From Michigan 3 of 8 specimens display lesions; 2 adults and one subadult have lesions and 5 subadults do not have lesions.

_Specimens examined._--Total number, 102 as follows: Arranged alphabetically by states and within each state by counties from north to south. Unless otherwise indicated, specimens are in the United States National Museum.

=Indiana.= _Huntington County_: Roanoke, 1. _Wells County_: Harrison Township, 1[76].

=Illinois.= _Lake County_: Deerfield, 3[60]; no locality more definite than county, 1[60] _Cook County_: Northfield, 1[60]; La Grange, 1[18].

=Michigan.= _Tuscola County_: 8 mi. N Caro, 1[76]. _Santilac County_: Deckerville, 1[76]. _Allegan County_: Swan Creek Exp. Station, 1[76]; Swan Creek Farm, 1[76]; T. 2N, R. 14W, 1[76]; Allegan, 1[76]. _Livingston County_: George Reserve, 1[76]; 1/2 mi. N Unadilla, 1. _Oakland County_: Rochester, 1[76]. _Macomb County_: Romeo, 1[76]. _Washtenaw County_: 5 mi. SW Ann Arbor, 1[76]. _Branch County_: vic. Coldwater, 1[76].

=North Carolina.= "near Marshall," 1.

=Ohio.= Northern part of state, 1[81]. _Williams County_: Stryker, 1[60]. _Lucas County_: Monclova, 1[60]. _Erie County_: Sandusky, 2[76]; marsh near Sandusky, 1[76]; Berlin Heights, 1[76]; no locality more definite than county, 1[2]. _Wood County_: 10 mi. NE Bowling Green, 1[76]; Bowling Green, 4[76]; 3 mi. E Bowling Green 1[76]; Plain Township, 1[2]; Portage Township, 1[60]. _Loraine County_: Wellington, 1[81]. _Huron County_: west of Monroeville, 1[76]. _Summit County_: Ira, 3[81]. _Portage County_: Suffield, 1[81]. _Hancock County_: Vanburen, 1[76]; Findlay, 1[81]; 9 mi. S Findlay, 1[76]; no locality more definite than county, 7 (2[76], 2[81], 3[2]). _Mahoning County_: Ellsworth, 1. _Crawford County_: "near Crestline," 1[81]. _Delaware County_: Sunbury, 1[2]; Lewis Center, 1[81]; no locality more definite than county, 1[81]. _Licking County_: Johnstown, 1[2]. _Fairfield County_: Baltimore, 1[81]; Violet Township, 1[81]. _Meigs [= Gallia?] County_: Vinton, 1[81].

=Pennsylvania.= _Erie County_: McKeen Twp. 1. _Crawford County_: Springboro, 1[1]; Pymatuning Swamp, between Hartstown and Shermansville, Sadsbury Twp., 3[9]. _Mercer County_: Shenango Twp., 1. _Lawrence County_: Little Beaver Twp., 1. _Butler County_: Leasuresville, 1[9]; Clearfield Twp., 1; Valencia, 1[9]. _Armstrong County_: Ford City, Burrell Twp., 1. _Indiana County_: Smicksburg, 1; N. Mahoning Twp., 2; White Twp., 1. _Allegheny County_: South Hills, Pittsburgh, 1[9]; "near Pittsburgh," 1[9]; Fair Oaks, 1[9]. _Westmoreland County_: Bolivar, 1. _Dauphin County_: Middle Paxton Twp., 1. _Washington County_: Finleyville, 1; Rea, 5; Beallsville, 1[1]; Claysville, 1. _Green County_: Deep Valley, 1; Waynesburg, 1; Jefferson, 1; Cumberland Twp., 1. _Fayette County_: Acme, 1[9]; _Somerset County_, 1. _Lancaster County_, 1.

=West Virginia.= _Randolph County_: Huttonsville, 1.

=Wisconsin.= _Sauk County_: Sumpter Twp., 1[60]. _Dodge County_: Beaver Dam, 1[50]. _Dane County_: Madison, 1; McFarland (= MacFarland), 1.

=Mustela rixosa campestris= Jackson

Least Weasel

Plates 14 and 15

_Mustela campestris_ Jackson, Proc. Biol. Soc. Washington, 26:124, May 21, 1913.

_Putorius pusillus_, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880, Omaha.

_Mustela rixosa campestris_, Swenk, Journ. Mamm., 7:329, Nov. 23, 1926.

_Type._--Female, adult, skin and skull; no. 171490, U. S. Nat. Mus., Biol. Surv. Coll.; Beemer, Cuming County, Nebraska; April 18, 1911; obtained by G. Sharp; x catalogue no. 8440.

The skull is unbroken. On the left side, C1 and P2 are missing; the other teeth are present and entire. The skin is excellently made and in a good state of preservation.

_Range._--South Dakota, Nebraska and Iowa. See figure 28 on page 180.

_Characters for ready recognition._--Differs from _M. r. rixosa_ and _M. r. allegheniensis_ in larger size: Hind foot more than 25 in males and ordinarily more than 22 in females; in males total length more than 216 and tail averaging more than 34; color possibly slightly paler than in _M. r. rixosa_ and averaging paler than in _M. r. allegheniensis_; from _M. frenata_ and _M. erminea_ of the same region by basilar length less than 32; tail less than 50, and lacking black pencil.

_Description._--_Size._--Male: Four adults from Nebraska yield average and extreme measurements as follows: Total length, 231 (225-237); length of tail, 36 (32-39); length of hind foot, 29 (28-31).

Female: Six adults from Nebraska yield average and extreme measurements as follows: Total length, 192 (184-225); length of tail, 35 (28-40); length of hind foot, 23 (20.5-26).

_Color._--Winter pelage ordinarily white; as described in _M. r. eskimo_ except possibly paler and certainly with line of demarcation on side of head between upper parts and underparts passing almost straight back without the dorsally directed reëntrant angles of white behind the eye and ear; least width of color of underparts in four specimens from Nebraska averaging 80 (49-89) per cent of greatest width of color of upper parts, but in a fifth animal in summer pelage the brown color of the upper parts encircles the body.

_Skull._--See measurements in table and plate 15; weight 1.1 grams (male from Brown Co., S. D.); basilar length, 30.7 in male from Clay Co., Neb., and 28.8 in female from same county; otherwise as described in _M. e. richardsonii_.

_Remarks._--In his revisionary treatment of the American races of _Mustela rixosa_, Myron H. Swenk (1926:313) credits Samuel Aughey with recording this animal, _M. r. campestris_, from Nebraska, as early as 1880, under the name _Putorius pusillus_. In 1908, Swenk recorded the animal from the same state under the name _rixosus_ and in 1913 the race _campestris_ was formally named by H. H. T. Jackson.

On the testimony of a friend who had previously obtained several specimens for him, Swenk (1926:321) records the least weasel from Oshkosh, Garden County, Nebraska, which is a marginal record of occurrence to the southwest for _M. r. campestris_.

At an early stage in the study of American weasels the writer examined the specimens from Nebraska saved by Mr. Myron H. Swenk and recorded measurements of them. However, at the time of writing this account the specimens were not available for examination and the account of coloration is accordingly incomplete.

The large size, particularly the large external measurements, comprises the principal distinguishing character of this subspecies of the least weasel.

Of the four adults examined from Iowa and South Dakota one exhibits lesions such as result from infestation of the frontal sinuses by nematodes.

_Specimens examined._--Total number, 21 as follows. Arranged alphabetically by states and by counties, from north to south in each state. Unless otherwise indicated, specimens are in the United States National Museum.

=Iowa.= _Howard County_: Chester, 1[12]. _Palo Alto County_: Emmetsburg, 1[65]. _Kassuth County_; Algona, 1[65]. _Clayton County_: National, 1. _Storey County_: Nevada, 1[65]. _Wapello County_: Ottumwa, 1[65]. _Henry County_: Mount Pleasant, 1[66].

=Nebraska.= _Holt County_: Page, 1[35]. _Madison County_: Norfolk 1[35]. _Cuming County_: Beemer, 1. _Hamilton County_: Chapman, 1[35]. _Clay County_: Inland to 1 mi. east thereof, 7[35].

=South Dakota.= _Brown County_: shore of Sand Lake, S. 15 T. 126N, R. 62W, 1. _Day County_: Waubay Migratory Waterfowl Refuge, 1. _McCook County_: Salem, 1[102].

=MUSTELA FRENATA= Lichtenstein

Long-tailed Weasel

(Synonymy under subspecies)

_Type._--_Mustela frenata_ Lichtenstein, Darstellung neuer oder wenig bekannter Säugethiere, pl. 42 and corresponding text unpaged. 1832.

_Range._--From southern Canada southward over all of the United States, México, Central America, Venezuela, and the republics of western South America to southern Perú and extreme northern Bolivia. All the life-zones from Alpine Arctic to Tropical are inhabited. In the extremely desert region of southeastern California and western Arizona the species is scarce or possibly absent although recovery of a skull (see under account of _M. f. neomexicana_) from near the center of this region at Potholes on the Colorado River, and a reported occurrence in the mountains of Baja California, México, indicate that a few individuals of the species live in favorable habitat even in this desert region.

_Characters for ready recognition._--Differs from _Mustela erminea_, in regions where the two species occur together, by tail more than 44 per cent of length of head and body and by postglenoidal length of skull less than 46 per cent of condylobasal length in males and less than 48 per cent in females (see under characters of the species); from _Mustela rixosa_ by presence of black pencil on tail, caudal vertebrae more than a fourth (2/5-3/4) of length of head and body, basilar length of skull more than 34 mm.; from _Mustela africana_ by absence of thenar pad on forefoot, underparts without longitudinal, median, abdominal stripe of same color as upper parts, upper lips narrowly (rather than broadly) edged with color of underparts, longest facial vibrissae extending to or behind posterior margin of ear; presence of p2; more inflated (see pls. 23 and 30) tympanic bullae.

_Characters of the species._--Size large: Total length 300 to 550 mm.; tail two-fifths to seven-tenths of length of head and body, with distinct black pencil at end; caudal vertebrae 19 to 23; skull with long precranial portion; postglenoidal length, expressed as a percentage of the condylobasal length, less than 47 in females and ordinarily less than 46 in males; upper parts brown; light-colored underparts, in summer pelage, tinged with buffy or yellowish and continuous from chin to inguinal region; some subspecies (southwestern United States, México, Central America, and Florida) with white or yellowish facial markings which do not occur in any other American species of the genus _Mustela_.

_Geographic variation._--Forty-two subspecies are recognized, and the species is geographically more variable than any of the other 3 American species. Color, color-pattern especially on the head, relative proportions of the tail, hind feet, body including the head, and shape and size of the skull are the principal features in which geographic variation has been noted. The variation in the skull extends to the basicranial region (shape and size of tympanic bullae and related structures), interorbital region and preorbital region.

_Natural History._--Habitat and Numbers.--As has already been remarked, the long-tailed weasel is absent from the extreme desert of the southwestern United States and northwestern México. Possibly the absence of water to drink is the limiting factor. In southern Nevada the finding of weasels only in places that were well watered, even though small rodents suitable as food for weasels were even more abundant in the surrounding desert, supports this possibility that the absence of water to drink is the limiting factor. Also at Berkeley, California, in early December of 1927 in the canyon at the head of Dwight Way and in the autumn and winter of 1928 in Strawberry Canyon on the campus of the University of California, I trapped extensively for this species in different habitats and obtained, in all, four individuals no one of which was farther than 10 feet from water. The lesser cruising range of the individual weasel than of, say, the coyote, probably explains why, in an arid region, for example Pahranagat Valley, Nevada, only the meadow mice and their riparian associates are preyed upon by the long-tailed weasel whereas the coyote preys upon these riparian rodents and also upon the kangaroo rats and other rodents which are so abundant in adjoining habitats that are devoid of water.

In areas where water is available every few hundred yards, no particular habitat seems to be avoided in summer providing there is food for the long-tailed weasel. In winter (January and March) there obviously was a choice of habitat, possibly occasioned by more abundant food or more satisfactory shelter, or both, in Centre County, Pennsylvania, where Glover (1943B) found the population density in the chestnut-oak habitat to be one weasel per 6.5 acres in areas of tree cuttings and slash and one weasel per 13.3 acres in the open forest. In the scrub oak-pitch pine forest type the population was one weasel per 26.4 acres in tree cuttings and slash and one weasel per 38.2 acres in the open forest. No weasel was found in an area of 9.6 acres comprising a wood lot, the edge of the forest, abandoned fence rows and an abandoned orchard. The two types of forest in which he did find weasels, 25 in all, comprised 381.6 acres. Glover's (_op. cit._) data is the only precise information known to me on actual numbers of long-tailed weasels in a given area of any considerable size.

Fluctuations which I elsewhere (1946:57) have designated as multiannual fluctuations occur in this species but seemingly not in the degree that they do in _Mustela erminea_. This difference between the two species is to be expected because _M. frenata_ does not range so far northward toward the polar regions as does _M. erminea_ and populations of most kinds of animals in the polar, at least in the arctic, regions are subject to more extreme and more regular fluctuations than are kinds of animals in temperate or tropical regions. Indication of the means by which decrease in the weasel population is brought about is afforded by Osgood's (1935:156) observations around Rutland, Vermont. In the late winter of 1934, tracks indicated that weasels left their usual haunts and hunted cross lots, vainly trying to find food. Testing of the small mammal population in the spring and summer of 1934 showed that it was at low ebb. In the fall of 1934 mice and shrews were abundant again but weasels seemed to be entirely absent. The decrease in the population of weasels lagged behind the decrease in the population of the herbivorous prey as did the subsequent increase; this, of course, is the normal relation of carnivorous species of mammals and their prey, at least in and above the Transition Life-zone.