Wild Ideas: The fierce and efficient weasel

Although I grew up in Virginia, where weasels are actually quite common, it took going to Canada years later to see my first one in the wild. I finally spotted one here in Virginia when I moved to Rappahannock County and saw one on a winter walk. It took a while to figure out that’s what I was looking at because it was high in a tree, where my landlady’s pack of ferocious Jack Russell and Cairn terriers had treed it. All I could make out was a long, dark, furry body. After a bit of research, I decided it was likely a long-tailed weasel, the most common weasel here.

The long-tailed weasel, also known as the bridled weasel, is common throughout much of Virginia. Photo by Matt Lavin via Wikimedia Commons.
The long-tailed weasel, also known as the bridled weasel, is common throughout much of Virginia. Photo by Matt Lavin via Wikimedia Commons.

Weasels belong to the mustelid family of mammals. Six kinds of mustelids are native to Virginia: the long-tailed weasel, the least weasel, two subspecies of mink, the fisher and the northern river otter. Although skunks have long been considered a mustelid, new DNA evidence indicates that they’re actually in a separate family, Mephitidae.

Except for the southwestern mink and the fisher, all of Virginia’s mustelids are known to occur or are likely to occur throughout most of the state, according to the Fish and Wildlife Information Service (VaFWIS) website (vafwis.org) of the Virginia Department of Game and Inland Fisheries (VDGIF). The southwestern mink and the fisher are in a few mountain areas near the western border.

Most of our mustelids also seem to have healthy populations. Only the least weasel and fisher are listed in the Virginia Wildlife Action Plan as species of concern, the former at the lowest level of concern, tier IV, indicating “moderate” conservation need and the latter at tier II, “very high” need. Although the fisher’s population has declined, it is slowly making a comeback, partly through government restocking.

All mustelids have glands that produce musk, which can be quite pungent in some species, particularly mink. Although minks, among some other mustelids, are trapped for their fur, we humans have generally shown a low regard for mustelids. We even use “weasel” as a derogatory term to describe people who are sneaky and untrustworthy. While sneakiness may not be a welcome trait for us highly social humans, it’s hugely beneficial to a small, lone predator such as the weasel. Add its cleverness, curiosity, tenacity, ferocity and elongated shape (useful in raiding burrows), and you have a highly efficient predator.

Encounters with Alaskan mustelids

I’ve always envied my brother, Dana, for a rare mustelid encounter he had while I was visiting him in Alaska some years ago. He, his wife and I were camping at Glacier Bay National Monument, and while we were having breakfast on the beach, Dana went back to the tent site because he wasn’t feeling well. He came back a few minutes later, excited at having seen a wolverine, the largest land-dwelling mustelid.

Wolverines, although ferocious in defending themselves and attacking their prey, are rarely seen by humans because they’re extremely shy of us and are famous for being able to vanish when they see us, able to climb a mountain in a matter of minutes. While we berated my brother for not sharing such a rare sighting with us, he said that he was afraid to come tell us for fear that his movement would scare it off.

While we were up at Glacier Bay, we visited a wildlife-biologist friend of Dana’s who lived nearby. The biologist told about encountering a wolverine on one of the routine hikes he took to observe wildlife in Alaska’s outback. He was far from his campsite when he realized it was getting dark. Having no camping gear with him, he took off his Xtra Tuffs (tall, waterproof boots known as “Southeast sneakers” along the rainy southeast coast of Alaska), crossed them, and used them as a pillow. He said he woke up in the night to a wolverine’s taking the second boot out from under his head. The biologist figured it was likely salt from sweat that had accumulated in the boot that attracted the wolverine, which fled when the biologist woke up.

Virginia’s mustelids vary widely in size, from up to 50 inches and 25 pounds for male otters to a mere nine inches and two ounces for male least weasels, making the latter the smallest carnivore in North America. Female mustelids are generally smaller. The long-tailed weasel looks somewhat similar to the least weasel but is larger and has a black tip on the end of its tail. Minks and fishers are even larger and have darker fur.

Mustelids use their sharp teeth and weight to catch their prey, finishing animals off with a bite to the neck or the back of the skull. Virginia mustelids eat a wide range of small animals, including rodents, rabbits and other mammals, and ground-nesting birds and their eggs. They’ll even go after prey animals that are a bit larger than themselves and after weasels that are smaller. Fishers hunt on land and in streams, also preying on crayfish and fish.

River otters, which are primarily aquatic, prey primarily on non-game fish, which makes them “a boon to fishermen,” according the VDGIF. Small piles of fish scales near streams and ponds, as I’ve observed down at the ponds where I live, can indicate an otter has been hunting there. Crayfish are also important in their diet.

All mustelids have a voracious appetite, devouring pretty much all parts of their prey, including the stomach contents, which adds partially digested vegetation to their mostly meat diet. In referring to long-tailed weasels’ rodent-hunting prowess and appetite, the authors of “Mammals of the Carolinas, Virginia and Maryland” write, “Their great value as efficient mousers should earn this species protection around farmsteads.”

While weasels can help in managing rodent populations, they can also go after poultry. Kansas State University extension specialist F. Robert Henderson, on the Internet Center for Damage Management website (icwdm.org), suggests the way to exclude them is to close all openings larger than an inch in poultry pens or coops and block openings with half-inch hardware cloth, similar wire mesh or other materials.

I find mustelids endlessly fascinating. The playful nature of otters makes them especially hard not to love. While I’ve only seen river otters cavorting in zoos, I did once have the distinct pleasure of watching a pair of sea otters at play along the coast of Alaska. I was visiting my brother and his wife, who live in Juneau, and at the time a short-tailed weasel had also moved into their basement, which is regularly invaded by mice and red squirrels. While the weasel did a bit of damage itself through chewing, that didn’t compare to what the rodents were doing, so my brother and his wife welcomed the little predator as a temporary lodger.  

Pam Owen
About Pam Owen 338 Articles
Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term "biodiversity," "Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”