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Photo © Peggy Popp
Least Weasel (Mustela nivalis) is the state's smallest weasel but exhibits typical mustelid form having a long, slender body and long neck. Its summer coat is chocolate-brown in color and lacks black on the tail and it molts to a white pelt during autumn (Oct-Nov). Least weasels are a grassland species found in a variety of open habitats such as marshlands, farmlands, grassy fields, and moist to wet prairies. The breeding season is typically during the spring and autumn, although it can occur throughout the year. Least weasels are among the smallest carnivores in the world and have a diet of mice, birds, eggs, insects, and young rabbits. This species is not actively tracked in the Natural Heritage Inventory Database, but it could be tracked in the future if there is further evidence of its decline.
The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Least Weasel (Mustela nivalis). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.
Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.
| Summary Information | |
|---|---|
| State Status | none |
| Federal Status in Wisconsin | none |
| State Rank | SU |
| Global Rank | G5 |
| Tracked by NHI | W |
| WWAP | r-SIN |
A guidance document is not available at this time. Use the information from the other tabs and contact local biologists, as needed, to develop management and avoidance strategies.
Click to view a larger version. Please considering donating a photo to the Natural Heritage Conservation Program for educational uses. Photo use
Least weasel and cache of dead mice under cover board
Photo © Jeff Lorch.
Least weasel in winter plumage
Photo © Peggy Popp.
Least weasel in summer plumage
Photo © Peggy Popp.
Least weasel in summer plumage
Photo © Peggy Popp.
Least weasel in transitional plumage
Photo by Bridget Rathman, WDNR.