Intergradation with the subspecieseskimois suggested by the short tail of the specimen from fifteen miles east of Atlin, British Columbia; in other particulars that specimen, a skin-alone, agrees with the subspeciesrixosa. Intergradation withcampestrisis indicated by increased size of some specimens from North Dakota, and is suggested withallegheniensisby the color of specimens from Wisconsin and Illinois. Three specimens from Winona County, in southeastern Minnesota, unfortunately are skulls-alone without external measurements. Also, two of these skulls are of young animals. The one adult, unsexed, is from Crystal Springs. Selected cranial measurements are: basilar length, 28.5; length of tympanic bulla, 10.9. These measurements accord with those of males of the subspeciesrixosato which the specimens from Winona County, therefore, are here assigned. The possibilities have not been excluded, however, that the adult is an unusually large female of the subspeciescampestrisor a male ofallegheniensisthat has tympanic bullae longer than average for that subspecies.
Some hesitation is felt in assigning the specimens, 8 in all, from eastern Canada to the subspeciesrixosa. The skin-alone from Eagle River and the skin, with part of the skull, from St. Michael Bay, are in transitional pelage and are of no help in appraising subspecific characters. The one adult specimen which does have a complete skull is from an island south of the Comb Hills. This animal in all respects agrees with selected individuals ofM. r. rixosafrom Saskatchewan, but each of the five other skins in summer pelage has spots of dark brown color on the breast. Only about one specimen in three ofrixosafrom Saskatchewan is similarly marked. Furthermore, on some of the specimens from eastern Canada the spots are larger than on any of the animals from farther west. The greater frequency of brown spots on the breast, the larger average size of these spots, and the darker average coloration of the upper parts are suggestive of geographic variation, the existence of which has to be proved by additional and more complete specimens from eastern Canada. For the time being, specimens from there are tentatively assigned to the racerixosa.
Of 56 subadult and adult skulls only 3 (1 North Dakota; 1 Calgary, Alberta; and 1 Island S Comb Hills, Queb.) display lesions resulting from infestation of the frontal sinuses by nematode parasites. None of the young skulls shows such infestation.
Specimens examined.—Total number, 87 as follows. Arranged alphabetically by provinces and states and within each from north to south. Unless otherwise indicated, specimens are in the United States National Museum.Alberta.Miette River, 1[77]; 5 mi. NW Camrose, 1[77]; Camrose, 2 (1[77], 1[31]); "near Camrose," 2[77]; Forks Blindman and Red Deer rivers, 1[60]; Innisfail, 1[86]; Veteran, 1[93]; Diddsbury [= Didsbury], 1; Calgary, 2 (1[93], 1[2]); Shepard, 1[86].British Columbia.Clarks Ranch, Halfway River, Peace River Dist., 1[85]; 15 mi. E Atlin, 1[8]; Wistaria, P. O., 3 (2[77], 1[85]); Ootsa Lake, 1[85].Labrador.Davis Inlet, 1[60]; 30 mi. upriver and 20 mi. toward Groswater Mts., Eagle River, 1; St. Michael Bay, 1.Mackenzie.Old Fort Reliance, 1[2]; Fort Resolution, 2; Fort Smith, 1.Manitoba.Gypsumville, 1[86]; Lake St. Martin Reserve, 1[86].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].
Specimens examined.—Total number, 87 as follows. Arranged alphabetically by provinces and states and within each from north to south. Unless otherwise indicated, specimens are in the United States National Museum.
Alberta.Miette River, 1[77]; 5 mi. NW Camrose, 1[77]; Camrose, 2 (1[77], 1[31]); "near Camrose," 2[77]; Forks Blindman and Red Deer rivers, 1[60]; Innisfail, 1[86]; Veteran, 1[93]; Diddsbury [= Didsbury], 1; Calgary, 2 (1[93], 1[2]); Shepard, 1[86].
British Columbia.Clarks Ranch, Halfway River, Peace River Dist., 1[85]; 15 mi. E Atlin, 1[8]; Wistaria, P. O., 3 (2[77], 1[85]); Ootsa Lake, 1[85].
Labrador.Davis Inlet, 1[60]; 30 mi. upriver and 20 mi. toward Groswater Mts., Eagle River, 1; St. Michael Bay, 1.
Mackenzie.Old Fort Reliance, 1[2]; Fort Resolution, 2; Fort Smith, 1.
Manitoba.Gypsumville, 1[86]; Lake St. Martin Reserve, 1[86].
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].
Least Weasel
Plates14,15and41
Putorius allegheniensisRhoads, 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.
Putorius allegheniensisRhoads, 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 figure28on page180.Characters for ready recognition.—Distinguished fromM. r. rixosaby three average differences, namely, darker color, shorter tympanic bullae, and smaller size of males; fromM. r. campestrisin 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; fromM. frenataandM. ermineaof 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 plates14and15).—Basilar length 29.7 and 28.6 in male and 28.0 in female; weights unavailable; otherwise as described inM. 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 ofM. rixosa.
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 figure28on page180.
Characters for ready recognition.—Distinguished fromM. r. rixosaby three average differences, namely, darker color, shorter tympanic bullae, and smaller size of males; fromM. r. campestrisin 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; fromM. frenataandM. ermineaof 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 plates14and15).—Basilar length 29.7 and 28.6 in male and 28.0 in female; weights unavailable; otherwise as described inM. 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 ofM. 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 namepusillusand it was not until 1900 that Samuel N. Rhoads proposed the namePutorius 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 ofMustela 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 ofallegheniensisin 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 subspeciescampestrisandrixosato 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 rixosain Pennsylvania parallels the speciesMustela frenatain 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. AlsoMustela ermineain this same region (range of the subspeciesMustela 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 ofM. erminea cicognaniiin that territory is so little more than inrixosathat the latter possibly cannot successfully compete with theermineastock which may already occupy the ecologic niche to whichrixosais adapted. It will be remembered that in western North America in territory seemingly climatically suitable forrixosait occurs no farther southward than the line below whichM. ermineahas become reduced to a size comparable with that ofM. 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.
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.
Least Weasel
Plates14and15
Mustela campestrisJackson, 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.
Mustela campestrisJackson, 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 figure28on page180.Characters for ready recognition.—Differs fromM. r. rixosaandM. r. allegheniensisin 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 inM. r. rixosaand averaging paler than inM. r. allegheniensis; fromM. frenataandM. ermineaof 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 inM. r. eskimoexcept 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 plate15; 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 inM. e. richardsonii.
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 figure28on page180.
Characters for ready recognition.—Differs fromM. r. rixosaandM. r. allegheniensisin 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 inM. r. rixosaand averaging paler than inM. r. allegheniensis; fromM. frenataandM. ermineaof 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 inM. r. eskimoexcept 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 plate15; 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 inM. e. richardsonii.
Remarks.—In his revisionary treatment of the American races ofMustela rixosa, Myron H. Swenk (1926:313) credits Samuel Aughey with recording this animal,M. r. campestris, from Nebraska, as early as 1880, under the namePutorius pusillus. In 1908, Swenk recorded the animal from the same state under the namerixosusand in 1913 the racecampestriswas 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 forM. 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].
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].
Long-tailed Weasel
(Synonymy under subspecies)
Type.—Mustela frenataLichtenstein, 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 ofM. 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.
Type.—Mustela frenataLichtenstein, 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 ofM. 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 fromMustela 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); fromMustela rixosaby 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.; fromMustela africanaby 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 genusMustela.
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 inMustela erminea. This difference between the two species is to be expected becauseM. frenatadoes not range so far northward toward the polar regions as doesM. ermineaand 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.
The average distance away from the central den which four weasels (sex unspecified) traveled in a single night at Ames, Iowa, was 312 feet; the maximum distance was 642 feet. These data were obtained in the winter of 1939 by Polderboer, Kuhn and Hendrickson (1941:115) who studied the tracks in the snow. In Manitoba, Criddle and Criddle (1925:143) noted that a female which lived in their basement often wandered more than half a mile away in search of food. In Michigan, Quick (1944:75) found the maximum distance traveled in one day (= night?) by a large male to be 3.43 miles although two miles was the average distance traveled by this individual. In 1942, from January 4 to March 4, in Centre County, Pennsylvania, Glover (1943B) studied tracks of 11 males and 10 females, in newly fallen snow, and ascertained that the distance traveled in a single night averaged 704 (60-2535) feet for the male and 346 (20-1420) feet for the female. The weasels in the open timber traveled farther per trip than those in the brushland and dense stands of trees.
An adult female (now the holotype ofMustela frenata nevadensis) seen running across a field, and, I think, unaware of my presence, at every bound bent her back up so far that she reminded me of a measuring worm. For part of the time when running, the tail was held off the ground straight out behind, and then, for a while, inclined upward at an angle of about 45°. Another weasel that I saw in the daytime, and that I think was unaware of my presence, was bounding along among theBaccharisbushes on the south-facing slope of Dwight Way Canyon, Berkeley, California. This individual, at each bound, arched the back up so high as to remind me, again, of a measuring worm.
The long-tailed weasel is a land mammal and unlike its close relative, the mink, is seldom seen in the water. That it can swim, however, is attested by the capture of one while it was swimming across the Río Ramos in México (Davis, 1944:381). Also, Green (1936), in May, in Gratiot County, Michigan, saw a weasel, running with aPeromyscusin its mouth. The weasel dropped the mouse, entered the water and swam to a hole among stones.
More instances of climbing, than of swimming, have been reported in the literature for the long-tailed weasel. Seton (1929 (2):625) quotes William M. Graffius of Pennsylvania as having seen a weasel closely pursue a red squirrel nearly to the topmost branch of a large hemlock. When the squirrel loosed its hold and dropped into a stream, the weasel descended to the ground and caught and killed the squirrel when it emerged from the water. Pearce (1937:483), in central New York State, on July 29, 1931, watched a weasel chase a chipmunk up a black cherry tree ten inches in diameter, and noted that the first rush carried the weasel "straight up the trunk for approximately 10 feet, where it hesitated momentarily before continuing. Then, instead of climbing vertically, it made progress by traveling in short ascending spirals around the trunk, scarcely making 3 feet in height for each circuit of the tree. Upon reaching the limb by which the chipmunk escaped, the weasel followed out along this in the same spiral manner. This limb had a diameter of about 4 inches at its base and extended upward at an angle of perhaps 20 degrees above the horizontal . . . it made its way head first almost down to the ground, using the same spiral mode of progress, but at a leisurely pace. . . . While traveling down the side limb it appeared practically to wrap its sinuous body around the limb."
A male long-tailed weasel, from Colorado, which I kept captive was often fed freshly killed mice. These I thrust through one of the small openings in the wire mesh. The weasel quickly learned to seize any part of a mouse thus introduced and his tugging aided in getting the mouse into the cage. Occasionally a mouse too large to be got through the mesh had to be withdrawn. In such an instance, if the weasel had already had hold of the mouse, he would screech frightfully. I have heard no other vocal sounds from a weasel except a kind of purring.
The sense of smell apparently is well developed; at any rate it is keen enough to allow the weasel to follow the trail of an intended victim by the scent left by the latter. Murie's (1935:321-322) account, for example, of a weasel pursuing a snowshoe rabbit gives clear evidence that the weasel relied on scent in following the rabbit.
A captive male weasel obtained at Gainesville, Florida, stamped his hind feet when annoyed (Moore, 1945:259).
A male from Colorado that I kept for months in a cage at Lafayette, California, was several times found in a sleep so deep that he was awakened with difficulty. Seton (1929 (2):629-630) writes: "In my small menagerie, I have had half-a-dozen Weasels of the New York species. Their sleeping dens are arranged so as to be easily and silently opened. Several times I have lifted the lid to find the weasel in a deep sleep—a sleep so profound that I had to poke him vigorously with a stick before he awoke, looked up, and rushed forth with a little puff of wrath, and a little puff of smell."
Feces and urine were ordinarily deposited in one particular place by each of the captive weasels that I have observed. Hamilton (1933:294) records that a large maleM. f. noveboracensis, in a week, averaged 10 evacuations every twenty-four hours, that urination immediately precedes defecation, and describes the feces as black or brown, long and narrow and often spiral-shaped owing "to the matted fur of some rodent that had been eaten." Quick (1944:77) writes, concerning four winter dens in Michigan, that "The latrines of weasels were in the entries of used dens and scats could be collected there by the handful." Polderboer, Kuhn and Hendrickson (1941:116) in the spring of 1939 at Ames, Iowa, gathered scats "from latrines found at the entrances of burrows and from latrine chambers found within burrows." Scats were found by them in the linings of some nests.