Beyond Your Backyard - These Weasels Three

By Kimberly J. Epp

Throughout the years, I have written about many of the species which call Saskatchewan home.

Each species deserves its own column, however these three species of weasels often get confused...the Long-tailed Weasel, the Short-tailed Weasel, and last but certainly not least, the Least Weasel.

Sometimes snow is late in coming, but mammals such as weasels and hares still turn white as per the shortening of the days. This leaves them vulnerable to predation and the lack of a subnivean layer to protect them. (Photo credit Michael St. Laurent)

"The Long-tailed Weasel" 🦦

The Long-tailed Weasel is the largest of the three weasels, at a weight of 85 to 400 grams. It's tail is roughly the same length as its body, which is a good way to identify it in the field. It's total body length is 34 to 49 cm. It's preferred habitat is open country.The black tail tip, like a paintbrush, is roughly an inch in length.

A Long-tailed Weasel carries prey nearly as big as itself. Again, note the black tip of the tail, but a longer tail than that of the Short-tailed Weasel. (Photo credit Steve Howze)

It's winter coat is pure white except for the black tail tip. It's summer coat is brown, with a yellowish-brown underbelly. During the fall moult, the white fur first appears on the animal's belly and then spreads towards the back. The reverse occurs in the Spring, when the brown coat begins to form on the weasel's back and moves towards the belly.

Although these weasels often prey on larger animals than its other weasel relatives, voles and mice still make up a majority of its preferable prey. Weasels are obligate carnivores, which means they rely on a diet of meat to survive.

This Long-tailed Weasel followed the trail of mice and squirrels right to the window where Lezlie Whiting was feeding her birds. After a few photos, to both the amazement of her cat and said hooman, he munched a few seeds and then went off to look for "real food"! Lezlie stated that this was one of the best wildlife interactions she has ever had. At one time, she even had a Least Weasel in her garage. (Photo credit Lezlie Whiting)

Long-tailed Weasels mate in midsummer, but through delayed implantation, their young aren't born until April or May. The female makes her nest in the former burrow of a ground squirrel or mouse that she has eaten. She lines the nest with the fur and feathers of her prey. The six to nine young are born blind, hairless and helpless.

"The Short-tailed Weasel" 🦦

Also commonly referred to as the Ermine, the Short-tailed Weasel is the most common weasel, and thus is the most commonly photographed. This weasel weighs 45 to 106 grams. It's black-tipped tail is roughly half the size of its body. Its total body length is 22 to 32 cm.

A perfect snapshot of a Short-tailed Weasel. The photographer saw the tail length and black tip, and also noted that the ermine was after a squirrel, which later took off at through the back of the firewood storage shed. (Photo credit John C. Corden)

Its diet consists mainly of voles and mice, but this weasel will also prey on gophers, pikas, rabbits, chipmunks, shrews, bird eggs and nestlings, insects, and even amphibians. They eat every part of a mouse except for the stomach, which they carefully excise and leave on a rock or other hard surface. Now there's a fact you can (but maybe shouldn't) share with your friends!

A Short-tailed Weasel peaks out from under the subnivean layer, the layer between the earth and snow. Small mammals, such as voles and weasels, tunnel under this layer which is usually at zero degrees (even while above the snow it may be freezing cold). (Photo credit @samuel_nature_photographie)

Like all weasels, extra prey is hoarded in the den in the winter during leaner times. Like the Long-tailed Weasel, delayed implantation also occurs in the Ermine. The female cares primarily for the young (5 to 12 kits) until the male rejoins them at typically 5 to 6 weeks, where the adults then take the kits on hunting trips.

A rare capture of an ermine in fall moult snacking on a cottontail rabbit! The ermine is in the process of moulting, but that didn't stop him from getting his prized meal. What he doesn't eat will go into his underground cache. (Photo credit Sherrie Duris)

"The Least Weasel" 🦦

A Polar Bear and a Least Weasel walk into a bar. Now, supposing they were of equal size, who would win the brawl? Surprisingly, for its size, the Least Weasel is the most ferocious carnivore in the world. It is quick, scrawny, and built to fight. It will even kill prey twice its size. A Polar Bear is slower, and its prey isn't nearly half its size. So, the two carnivores decide to part ways after sharing a fresh, warm and slightly dry "stoat".

Least Weasels are the tiniest weasels, but there is a lot of energy in that tiny engine! They weigh 25 to 73 grams and are 15 to 22 in length. Their tail is 2.2 to 4.2 centimeters in length. Of all the predators which mice most fear, the Least Weasel is likely to top their list. This pint-sized fiend is small enough to squeeze into a mouse tunnel and den, and kill the entire population within minutes. It will then store the uneaten prey in its hoard for later.

The Least Weasel is not only the smallest weasel in the world, but it is also the smallest true carnivore in the world. But don't call this tiny weasel least! It may get upset and weasel war dance! This tiny, ferocious weasel may be the reason weasels get a bad rap. The polar bear agrees! On average, the Least Weasel consumes about 1 gram of meat an hour to keep up its high metabolism. It eats nearly its own weight in food each day.

People seldom see these little guys as they prefer to hunt at night. Any encounter, such as if someone lifts a piece of wood or hay bale, is usually very brief. Their winter plumage is pure white save for a few black hairs at the tip of their short tail. These weasels prefer to dine on voles, mice, and insects. They will dine on birds and eggs if the opportunity arises.

A Short-tailed Weasel with it's summer coat. Note the black tip of the tail, which Least Weasels do not have. (Photo credit unknown)

The den is a former burrow and nest of a vole. Well, its actually a bed and breakfast type of a deal. The vole gets eaten, the den gets taken, and the nest is then refurbished with the soft warm fur of said vole. Ah, nature.

After a gestation of 35 days, one to ten pink and wrinkled young are born. They are something only a mama can love...that is, only until they reach 7 weeks. Then they are on their own. There is no delayed implantation with these weasels, and their young can be born during any month of the year.

Now that you know a few facts about our wily weasels, keep an eye out for their bounding and loping tracks, especially after freshly fallen snow. Small 5-toed track imprints with long leaps in between typically show the paired pattern of a weasel.

Winter tracks of a Short-tailed Weasel. Like squirrels, they jump and bound in the snow. (Photo credit Wes Leigh)

🦦 Read about the mink, another animal in the weasel family, by clicking here or by copying and pasting the link below in your browser

https://www.mjindependent.com/lifestyles/2020/2/12/beyond-your-backyard-meet-the-mink

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Epp is a former Environmental Educator. She is also a writer, with a focus on nature and wildlife. She is the Past President of the Moose Jaw Nature Society and runs nature programs for the society. She can be reached at kepp@shaw.ca or at (306) 681-3198.

You can also reach her, or current President, Rich Pickering, via the Moose Jaw Nature Society Facebook page. Please contact Rich if you wish to donate bird seed, suet or peanuts for the Wakamow community feeder. Thanks also to Rich for building the great new feeders!