The Least Weasel in Michigan

Abstract

The least weasel, Mustela rixosa (Bangs), smallest of known carnivores, has been shown by Glover Allen (1933) to be a circumpolar species occurring from Norway through Siberia and southwards to northern Italy and the Caucasus. It also occurs in Japan. In North America its distribution is from Alaska southwards to Montana and Nebraska, through Minnesota, Wisconsin, northern Illinois, Indiana, and Ohio, southeastern western Pennsylvania, and the mountains of North Carolina. Over this enormous range it appears to be sporadically distributed, or so uncommon, except at occasional times and places, that it is rare in collections; in many of the States included in its range, it was unknown until this century. In many large areas where it might be expected, it is as yet unrecorded. Among these are South Dakota, Iowa, northern southern Ontario, New York, West Virginia, and Virginia. It was reported in Minnesota as early as 1857, and the eastern subspecies was described from western Pennsylvania in 1901. 1904 found it reported in Ohio, 1905 in Nebraska, 1907 in Wisconsin, 1916 in North Carolina, 1925 in Illinois, 1927 in North Dakota, and 1928 in Indiana. Covert, in 1881, (Covert, Adolphe B., 1881, Natural in History of Washtenaw County, Michigan, p. 193) listed five species of weasel under names which today are not all readily assignable. One of these was indubitably the least weasel, but his specimens appear to have been lost or destroyed. Ned Dearborn, then at the University of Michigan's School of Forestry, in 1932 recorded the first Michigan specimen which can be verified today. This was caught by a cat at Rochester, in Oakland County. In March, 1936, I secured a second specimen from a cellar hole in Bloomfield Hills, Oakland County, and shortly after that, a mounted specimen from a farmer in Rochester. Fourth and fifth specimens were secured at Rochester in the winter of 1936-1937. A fur dealer of that town had received six that same winter, the first he had ever seen. With a view to the possibility of establishing a state-wide distribution for the species, it was decided to canvass the fur dealers of the state for additional records and specimens. To each of the 500 licensed fur dealers of Michigan an envelope was sent February 9, 1939, containing a letter stating that I was interested in determining the distribution of the least weasel in Michigan; a brief definition of the species which did not contrast it with other species occurring here; a sign for placing on a wall where trappers would see it, showing a picture of a least weasel, offering fifty cents a head for the first six specimens from any county, and giving directions for mailing; a government post card with form to be filled out stating how many least weasel skins had been seen from what 412