Part 56

Remarks.--Edgar A. Mearns in 1889 and the early nineties took several specimens of this weasel and it was principally on these that Bangs in 1896 (p. 8) based his description. The best material, however, is that from Elk River, Minnesota, collected in later years by Bernard Bailey, and supplemented by one specimen taken in 1885 by Vernon Bailey and another by his sister Anna Bailey in 1891 at the same place.

Mustela frenata spadix has just one structural feature of a "unique" kind which serves to differentiate it from the geographically adjoining subspecies. This feature is large size. The other diagnostic characters ascribed to spadix are of an intermediate sort--intermediate as between two extremes, one found to the westward in longicauda and the other to the eastward in noveboracensis. For example, the dark-colored upper parts are merely darker than in longicauda and merely lighter than in noveboracensis. The color is not "different"; it is only "intermediate." Furthermore, each of the characters ascribed to spadix, including large size itself, undergoes change from one part of its geographic range to another; the characters are not constant over a wide area. Indeed, excepting the large size which remains relatively uniform over the northern two-thirds of the range, no two localities have been found from which the specimens can be said really to agree in characters.

By way of illustration, the coloration of the upper parts may be cited. Near the range of noveboracensis the average coloration of individuals from one locality is only a little lighter than in noveboracensis. Farther westward the average coloration is a little lighter and farther westward yet, toward the range of the extremely light colored longicauda, the average coloration is lighter still. Although all these animals are darker than longicauda and lighter than noveboracensis, those from the three places do not agree among themselves. Because of the lack of more than one character of a "unique" kind and because of the inconstancy, geographically, of other characters, and for that matter, lack of constancy geographically in combination of characters, the writer regards spadix as a barely recognizable subspecies.

Examination of the specimens of spadix shows that the individual variation in a single species is greater in a region of intergradation than it is some distance inside the borders of the geographic range of a well-marked subspecies. This is illustrated by three specimens of M. f. spadix in fresh summer pelage from the single locality, Elk River, Minnesota. In these, the color of the upper parts varies from a little darker than Cinnamon Brown to Vandyke Brown. At any one locality well within the range of longicauda, or noveboracensis, there is nowhere nearly so much variation in color, even in much larger series of specimens.

Study of the specimens here assigned to spadix reveals that some features regarded as of diagnostic value for one or the other of the two races, longicauda and noveboracensis, behave differently. For example, the dark coloration of the upper parts, which is characteristic of noveboracensis, manifests itself far westward within the range of spadix whereas the wider extent of the light-colored underparts, which is characteristic of longicauda, and the Olive Ocher, rather than Pale Orange Yellow, color of these underparts, are seen in varying degree all the way across the range of spadix. Thus, these animals are colored above like noveboracensis and below like longicauda, but not vice versa. In these animals, then, the longicauda type of underparts is dominant, in one sense of the word, over the noveboracensis type of underparts, and the noveboracensis type of upper parts is dominant over the longicauda type of upper parts. Each of these features is subject to actual intergradation and does not always behave as a "unit character," that is to say, one which is either present or absent. However, the noveboracensis type of upper parts is carried much farther west before being diluted than is the noveboracensis type of underparts. Indeed, within the range of noveboracensis itself, the broad extent of the longicauda type of underparts is manifest. This is, of course, near the western margin of the range of noveboracensis.

The large size of males of spadix, as exemplified by specimens from Elk River (see measurements on p. 421), seems to be retained across the northern part of the range here assigned to the subspecies. This larger size than is found in longicauda from Alberta, is shown also by some specimens from eastern North Dakota which are assigned to longicauda. However, the average of these Dakotan specimens, all characters considered, is nearer to my concept of longicauda.

Inspection of the cranial measurements of spadix shows also that in addition to its large size it is distinguishable from any one of the geographically adjoining races by its relatively (to basilar length) greater, as well as actually greater, mastoidal breadth. This might be included with size as a unique character distinguishing spadix from longicauda and noveboracensis. However, it is not clear whether or not this greater mastoidal breadth is more than a function of the large size.

Excepting the greater mastoidal breadth and generally larger size of the skull, the cranial features distinguishing males of spadix from longicauda are features in which spadix shows approach to noveboracensis. This is true, in spadix, of the relatively longer (in comparison with longicauda) rostrum, relatively lesser zygomatic breadth, relatively shallower braincase measured at the anterior end of the basioccipital, and relatively deeper skull as measured at the posterior borders of the last upper molars. This same approach to noveboracensis already has been pointed out with respect to color of the upper parts and is evident also in the relative shortness of the tail which averages only 51 per cent of the length of the head and body rather than 55 per cent as in longicauda.

Because the longicauda type of animal previously has been regarded as specifically distinct from the noveboracensis type of animal, comment is offered below on selected specimens, referred to spadix, which are regarded as intergrades with noveboracensis or with other subspecies.

No. 8722, Univ. Wisconsin, adult male, in the white winter coat, from north central Itasca County, Minnesota, obviously has characters of M. f. spadix or longicauda that occur to the west and M. f. noveboracensis of the east. Selected outstanding characters of longicauda are its long tail, anteriorly truncate tympanic bullae and large teeth. Characters indicating its affinities with noveboracensis are smaller size of skull, general narrowness of skull, and relatively low tympanic bullae. The skull is intermediate as regards several individual structural features. For example, although long and narrow and in this feature more nearly approaching noveboracensis, the skull is wider than usual in that subspecies and thus approaches that of longicauda or spadix. The hind foot, in the dried state, measures 47 millimeters. This large hind foot, obviously long tail (the specimen lacks external measurements), and anteriorly truncate bullae constitute basis for here referring the specimen to spadix. However, the seemingly small size of the body and the narrow skull clearly show relationship to noveboracensis.

Specimens, referred to spadix, from northern Iowa, are instructive as showing what happens where the ranges of noveboracensis, primulina, spadix, and perhaps longicauda, meet. No. 47167, Univ. Mich. Mus. Zoöl., a nearly adult female, taken on November 22, 1915, at Island, Clay County, and in process of assuming a brown winter pelage, retains enough of the dark summer pelage to show that the color was slightly lighter than average for spadix. The color pattern, white lips, and extension of light color of the underparts onto the feet, agrees with spadix or longicauda as does also the long tooth-row. The overall length of the skull is intermediate between that of spadix and primulina. The proportions of the anterior part of the skull and of the tympanic bullae resemble those found in primulina. A subadult male skull only, no. 123846, American Museum of Natural History, from Webb, Clay County, shows approach to primulina in the narrowness of the rostrum.

A young male from Ruthven, Iowa, no. 48340, Univ. Michigan, has a large skull approaching in size that of spadix, has the longicauda-spadix type of light-colored underparts and color pattern, and is slightly darker above than true longicauda. Another subadult male in the white winter coat from Palo Alto County, no. 35756, Univ. Michigan, has a large skull, which shows approach to primulina in its narrowness anteriorly and in some other features. Although the tail is of moderate length, the body is large as in spadix or longicauda, and the length of the hind foot suggests spadix or longicauda.

A subadult male, no. 425a, Iowa State College, from Manson, Iowa, in brown winter pelage, agrees with primulina in the restriction of the area of the light color of the underparts and in less expanded zygomatic arches. The teeth are intermediate in size between those of noveboracensis and primulina on the one hand and those of spadix and longicauda on the other. In other respects it agrees with, or is more nearly like, spadix.

An adult female, no. 426a, Iowa State College, from Barnum, in the brown winter coat, agrees with primulina except that the orbitonasal length of the skull is more as in spadix and the presence of some light color on the lower part of the hind legs suggests spadix. The skull only, no. 440a, Iowa State College, labeled merely Webster County, Iowa, is almost a duplicate of no. 426a. A subadult male, no. 427a, Iowa State College, from Moorland, Iowa, only about six miles southeast of Barnum, likewise is indistinguishable from primulina except for having a white winter coat and in being relatively broad in the mastoidal region. Nevertheless, both of these animals are here referred to spadix because the average of specimens from this general area is nearer that of spadix. No. 497a, Iowa State College, an adult female in white winter pelage, from Ames, approaches primulina in the narrow rostrum and smaller teeth but otherwise approaches or even agrees with spadix.

Two adult males, without external measurements, from Pilot Mound, Iowa, have skulls quite like males of longicauda from Alberta. The only approach noted to eastern forms is the restricted color of the underparts on no. 2856, Coe College, which has a brown winter coat. The color of the underparts is not extended so far out on the feet as in longicauda. Also the tympanic bullae of this specimen are a trifle narrower. The other male, no. 2652, is in the white winter coat. The one female from the same place, no. 2660, Coe College, in brown winter pelage, has a skull notably unlike that of longicauda or spadix; the skull is narrower and practically indistinguishable from that of the largest female skull of primulina available from Lawrence, Kansas, save that the tooth-row is much longer. The color pattern also agrees with that of primulina or noveboracensis in that the color of the underparts extends only as far as the knee on the hind legs and is narrow on the belly. Nevertheless, another adult female, no. 120a from Amaqua Township, some 6 miles southwest of Pilot Mound, is in all respects typical of spadix. This is the more remarkable because another comparable specimen from less than 20 miles to the southwest in Worth Township is equally typical of primulina.

Two young females from Chester, Iowa, nos. 2656 and 2874/2873, Coe College, have skulls larger than those of corresponding age of primulina or noveboracensis. The color is as in spadix. The color pattern of the underparts also is as in spadix or longicauda except that the width of the area of light color on the belly is restricted somewhat although not so much as in noveboracensis or primulina. Of four males from the same place, also in the collection of Coe College, no. A2874 is a white skin only and does not provide diagnostic characters. The three other males, each in summer pelage, are marked and colored as are the two females from the same place except that male no. 2861 has the color of the underparts so much attenuated on the hind legs that it barely, uninterruptedly, extends to the feet. No. 2658 is young, or perhaps barely subadult. The skull is large and referable to spadix. The two adults, nos. 2861 and 2657, differ cranially from typical (Elk River, Minn.) spadix only in being slightly narrower across the mastoids and in having the bullae a little narrower. In these departures they show some approach to primulina and to noveboracensis. Another male, subadult, no. 2867, Coe College, from Decorah, which has acquired half of the white winter coat, agrees with the males from Chester except that the preorbital part of the skull is shortened much as in some specimens of primulina.

From Lansing, in extreme northeastern Iowa, a large subadult male, no. 2864, Coe College, of 453 mm. in total length and half through with acquiring the white winter coat, agrees with the males previously described from Chester except in having the palate narrower as in noveboracensis. The adult female available from Lansing, no. 2863/2862, Coe College, in white winter pelage except for the top of the head, although a large skin, has a skull smaller than that of any spadix or longicauda and of about the same size as that of no. 3838, Univ. Kansas Mus. Nat. Hist., of primulina, from Lawrence, Kansas, except that the skull of no. 2863/2862 is much narrower across the mastoids. This specimen, then, shows approach to noveboracensis in narrowness of the mastoidal region, to primulina in other respects and to spadix.

Many of these instructive specimens from Iowa, made available to the present writer by Mr. W. F. Kubichek, were brought together at the Coe College Museum by the late B. H. Bailey. Most of them were obtained from trappers who did not supply the conventional external measurements taken in the flesh. Even though these are lacking, the specimens clearly show that actual intergradation occurs where the ranges of M. f. longicauda, spadix, noveboracensis and primulina meet.

The dark color of the upper parts, restriction of the color of the underparts on the ankles with the result that the color reaches the toes in interrupted fashion, and large skull, of no. 18912 of the Museum of the University of South Dakota, from Roberts County, South Dakota, clearly place this specimen with spadix, rather than with longicauda. Likewise, male, subadult, no. 11376, Univ. South Dakota, from Clay County, South Dakota, is referable to spadix. Although without external measurements, the specimen obviously is large. The patch of summer pelage on its head and neck is darker than the summer pelage of longicauda, and the orbitonasal length is greater than the length of the tympanic bullae; all these features are characters of spadix. The adult male from Fort Sisseton, South Dakota, no. 188407, United States National Museum, figured by Merriam (1896, p. 20, figs. 7-9), is almost exactly intermediate between longicauda and spadix, although here referred to the latter.

Five specimens, nos. 147375, 147432, 147762, 148720 and 148721, U. S. Nat. Mus., including 3 skulls only from Beemer, Cuming County, Nebraska, are intergrades between M. f. longicauda, M. f. primulina and M. f. spadix. One skin is in white winter pelage and the other, a female, is in summer pelage which in coloration and color pattern agrees with that of spadix. External measurements of the male agree with those of longicauda. Measurements of the female agree with those of spadix except that the tail is shorter as in primulina. The skulls are as long as in longicauda but are more slender than in either longicauda or spadix although nearer the latter in this respect. In dorsal aspect, the skulls especially posteriorly to the orbital region, resemble primulina. All points considered, the animals seem best referred to spadix.

Although the degree of development of certain morphological features has been settled upon as indicative of the race spadix, some doubt remains as to where the western boundary of its range should be shown. This results from the fact that color has been taken into account as one diagnostic feature and this feature is lacking in the white winter specimens which, from the following places, are all that are available: Kittson County, Minnesota; Moorhead, Minnesota; Casselton and Valley City in North Dakota; Armour, South Dakota and Clay County, South Dakota. In summary, more specimens in the summer coat will be required to establish definitely the boundary between the ranges of longicauda and spadix.

Surber (1932:49) has referred to additional specimens of this weasel in the University of Minnesota Museum as from Winona, Hennepin and Isanti counties of that state.

At Elk River, Minnesota, B. Bailey (1929:156) found this species to be about half as abundant as Mustela cicognanii and that it is "more often found in the open timber and about the dry ridges and fields." Of seventeen adult or subadult skulls of this race from Minnesota, ten have obvious marks of infestation of the frontal sinuses. In no skull, however, has the infestation resulted in so much malformation, as occurs in noveboracensis.

Specimens examined.--Total number, 76, arranged alphabetically by states and from north to south by counties in each state.

=Iowa.= Lyon County: Granite, 1. Howard County: Chester, 6. Winneshiek County: Decorah, 1; 8 mi. NE Ossian, 1. Allamakee County: Lansing, 2. Clay County: Island, 1; Webb, 1. Palo Alto County: Ruthven, 1; no locality more definite than county, 1. Calhoun County: Manson, 1. Webster County: Barnum, 1; Moorland, 1; no locality more definite than county, 1. Boone County: Pilot Mound, 3; Amaqua Township, Sec. 19, 1. Story County: Ames, 1.

=Minnesota.= Kittson County, 1. Roseau County: 2-1/2 mi. SW Roseau, Jadis Township, 1. Itasca County: T. 61N, R. 26W, 1. Clay County: Moorhead, 2. Atkin County: Atkin, 1. Otter Tail County: Lake Lizzie, 1; Parkers Prairie, 1. Grant County: 3 mi. NW Barrett, 1. Benton (now Mille Lacs?) County: Princeton, 1. Sherburne County: Elk River, 14 (6, 4, 3, 1). Hennepin County: Fort Snelling, 6 (5, 1). Carver? County: Chaska, 1. Lac qui Parle County: Madison, 5 (3, 2); no locality more definite than county, 2 (1, 1). Yellow Medicine County: Wood Lake, 1. Blue Earth County: Rapidan, 1. County in question: Moore Lake, 1.

=Nebraska.= Cuming County: Beemer, 5.

=North Dakota.= Cass County: Fargo, 1; Casselton, 1. Dickey County: Oakes, 1.