Changing Planet

North America’s Smallest Carnivore Gets a New Coat for Winter

Least weasel pops up on American Prairie Reserve. Photo: Dennis Lingohr/APR

Many grassland species are uniquely adapted to life on the snowy plains, but the Least weasel (Mustela nivalis) completely commits to its cold weather camouflage. As autumn comes to an end, this mini carnivore sheds its dark fur for a solid white coat that helps it evade predators like hawks and owls hovering overhead. And the Least weasel’s winter strategy doesn’t stop with color. They are also known to breed in their shallow burrows under the snow and cache extra food to get through the season.

Like other members of the Mustelid family, including badgers, black-footed ferrets, and wolverines, the Least weasel doesn’t let its size (or name!) determine its attitude. They are fierce attackers of much larger animals despite weighing in at just a few ounces and measuring less than 10 inches in length. Some historians believe that the weasel reputation for bravery is why Plains Indians like the Shoshone, Blackfeet and Arapaho incorporated white weasel pelts into tribal fashion, war bonnets, and weapons. Of course, the beauty of the winter white fur was also a luxury that made pelts a popular trade item. Sacajawea even gifted two-dozen white weasel tails to William Clark for Christmas.


American Prairie Reserve (APR) is assembling a world class wildlife reserve in northern Montana, with the goal of one day creating a seamless 3.5 million acre grassland ecosystem. APR’s President Sean Gerrity is a National Geographic Fellow and was recently profiled by The Innovators Project. Learn more about the Reserve, including our science and restoration efforts, on the Reserve’s website

American Prairie Reserve (APR) is assembling a world class wildlife park in northern Montana, with the goal of one day creating a seamless 3.5 million acre grassland ecosystem. Learn more about APR, including our bison restoration efforts and how to visit, on the Reserve's website.
  • Charles Salekin

    These are fantastic little devils and cute as all get out. They definitely are ferocious by nature and full of energy – never stopping to rest seemingly, but always on the run. I understand that this is due to the fact that they do not store fat, nor have very warm pelage, but a high metabolic rate that constantly needs recharging.

  • Gary

    what a worthless animal

  • Sandra

    I lealieve the shrew is the smallest carnivore. We have a weesle come visit and get a little treat.

  • Sandra

    Should say believe.

  • Ravi


  • Jonathan Hensersky

    There are carnivorous insects that are smaller.

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