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.