The different types of weasels that live among us
The word ‘weasel’ brings to mind a squinty-eyed, fidgety, untrustworthy villain in a novel. Weasels have been vilified for quite some time, with dictionaries even from 1900 giving rather disagreeable definitions.
Weasels can look like villains, with the shifty, scampering way they move. But even as there are small mustelids, or members of the weasel family mustelidae like the ermine and long-tailed weasel, there are also bigger members of the weasel family that escape the poor view of the smaller members. Badgers are maybe not looked on as favorably as is the river otter, but those two are often spoken of more highly than small mustelids.
Not quite as large as the badger are the fisher and the mink, who are often ignored until the culprit of chicken coop thievery is sought.
We can bid the weaselly stereotype adieu with the first member of the weasel tribe we’re discussing today: The river otter.
Many of us have seen the otters at the zoo frolic and play, sliding down their slides and gamboling to and fro to the great amusement of all. Those are the playful river otters (Lontra canadensis), who behave much like sea otters in their sliding and general gamboling. They are a treat to watch and a great example for enjoying the current circumstancesif the place where they’re standing looks like a good place for a belly slide, then they slide! Sea otters are not closely related to river otters, belonging to a different genus (Enhydra), but are of the same family.
River otter fur, according to Robert Seabloom in Mammals of North Dakota, has “the highest durability rating of North American furs,” being both thick and nearly waterproof (144). River otters like their cousins the sea otters appreciate water and wet habitats. A wonderful place to see them is at the small openings in the water as spring melts the ice on bodies of watersometimes, depending on the conditions of the freezeup, river otters hunt underneath the ice and so places to surface are few in number. That increases the chance that you can spot a river otter!
Also like their cousins, river otters like fish a lot and mostly consume just that. But don’t worry, fishermen; our otters like to eat suckers, says Seabloom, so they won’t hurt your chances of landing a catch overmuch. It also is evident that their low population numbers will not influence the availability of fish.
Something common to the weasel family’s reproduction is delayed implantation, where the egg is fertilized during breeding season but the process just stops there for nearly a year. True gestation for the river otter is only two months, when the babies are actually developing. This holds true with many of the other weasels in our area as well.
With a species like the river otter, whose fur is highly durable, thick, and water repellent, it comes with no surprise that they were hunted extensively before hunting controls were established and still today are listed as endangered or threatened in other states. In our state, though, even despite the lack of reintroductions, sightings have been increasing. How wonderful! Like the river otter, fisher sightings (Martes pennanti) have also been increasing although little work has been done on the part of the humans.
Something that most of the rest of our weasel friends do not have worry about is low population numbers. In fact, the next weasel is the most wide-ranging habitat generalist of the entire family- the ermine, also known as the short-tailed weasel (Mustela erminea).
Ermines are small, only weighing in at about 0.2 lbs for the heavier males. They are not the smallest weasel on record, but are the smallest weasel that we can officially claim in Barnes County. (The smallest weasel is the least weasel (Mustela nivalis), which is also the smallest carnivore in North America. They weigh between 0.06 and 0.1 lbs!).
Ermines are brown in the summer with a black tip to their tail, and in the winter are the beautiful white common to ermine pelts seen in movies, although they do retain their black tail-tip.
Like ermines, long-tailed weasels (Mustela frenata) are brown in the summer (also with an ink-dipped tail that they retain in the winter) and also turn a stunning white in the winter.
As their names state, ermines or short-tailed weasels have shorter tails, of lengths between 2 ½ to 3 inches. Long-tailed weasels, though, have tails between 5 and 6 inches long. Apt naming!
It is very difficult to tell the difference between longtailed and short-tailed weasel prints, marks, and sign, although some experts can do so, according to Mark Elbroch’s Mammal Tracks and Sign.
Our next weasel resident is much larger, weighing 2-3 lbs: The mink (Neovision vision). Like the rest of the mustelids, mink appreciate a good wetland habitat but don’t hesitate to opportunistically seek out prey elsewhere, like rabbits, muskrats, and the abundant rodent populations.
Mink are born altricial like the great majority of the weasel tribe, although it takes only 6-8 weeks for them to learn and begin practicing hunting skills. Most of the other weasels take longer to be weaned and begin hunting for themselves.
Our last member of the weasel family might surprise youthey’re big, heavy, and walk comically with an inwardtoed gait.
No, not a skunk- they’re in their own family (Mephitidae).
This striped weasel has huge, strong claws and loves to dig after its pocket gopher prey, leaving behind a characteristically enormous hole big enough to drop an unsuspecting tire into.
The badger (Taxidea taxus) averages 15 lbs, just slightly smaller than its bigger cousin, the river otter.
Unlike the rest of the weasel family, badgers love the wideopen prairie that has an abundance of assorted gophers to dine upon and lots of open area to dig in.
Like many open-prairie animals, badgers have periods of inactivity in the winter- and who can blame them, in temperatures like the ones we’ve been in for about a week.