I've been enjoying the company of a little white carnivore this winter. Known by most people as simply a weasel, this particular fellow is none other than a short-tailed weasel, also widely known as an ermine.
Fearless, my ermine, as is characteristic of all species of weasels, it hunts mice, voles, shrews, and other small prey with purpose and efficiency. Few predators are as specialized and capable as are weasels.
First discovered in my open garage gnawing on a frozen piece of venison fat, I've come to enjoy the antics of the ermine as it darts about and disappears, only to reappear seconds later somewhere else nearby.
Observing its behavior and motion is an exercise of delight and wonderment because I never know where the ermine will "pop" up next or what it will do.
There are three species of weasels that live in Minnesota: short-tailed weasel/ermine, long-tailed weasel, and the smallest carnivore in the world, the least weasel.
In their northern range, weasels are the only members of the family Mustelidae, or weasel family, that turns white in the winter.
In autumn, white hairs replace their brown summer coat. The weasel then becomes pure white except for its black-tipped tail. Would-be predators like owls sometimes focus on the black spot on the tip of a weasel's tail when attacking a weasel, thereby causing them to sometimes miss capturing the weasel altogether.
Other members of the weasel family include the fisher, pine marten, badger, mink, otter, and wolverine.
The long, tube-shaped body and short legs gives the weasel a kind of "wiener dog" appearance. Weasels evolved this body design in order to enter holes or burrows as they search for such prey as rabbits and hares, small rodents, as well as birds, snakes, frogs, and insects. Long claws on their toes help them climb virtually anything.
Like most members of the weasel family, weasels are very active and have high metabolic rates, thus the reason they need to constantly hunt and eat. Ermines search for prey constantly while using their keen senses of sight, smell, and hearing to locate their prey.
When hunting, weasels don't let any nook or cranny go unchecked. They will disappear into a hole in a log or tree and pop out seconds later at an altogether different spot. Indeed, following a weasel with your eyesight as the animal hunts for food is almost impossible to do. Weasels are quick-footed, lightning fast, and experts in the art of disappearing.
Ermines are smaller than long-tailed weasels, but larger than least weasels. About seven inches to a foot or so in length, ermines weigh scarcely more than four or five ounces.
Yet despite their diminutive size, no predator on the planet is more fearless than a weasel is. Predators they are, weasels are also prey items for many other predators such as the aforementioned owl, in addition to foxes and other canids, hawks and falcons, bobcats and lynx, and other members of its own family like pine martens and fishers.
As written on the DNR website, "A unique reproductive aspect of most members of the weasel family is the process of delayed implantation." Weasels differ from most mammals in that, "...fetal development is a continuous process which begins at the time of conception." Following a weasel's mating season during late summer to mid-winter, "...the embryos resulting from fertilization undergo an initial development of about two weeks."
Afterwards, a lengthy dormancy period occurs whereby the embryos remain free in the uterus until the embryos implant on the uterus wall, fetal development begins, and the young are born about 30 days after the delayed implantation occurs. A female weasel can give birth to a dozen or more kits. And though most weasels don't live more than two years, some wild individuals can live longer.
Ermines spend their days and nights on the prowl. Always moving, always hunting, and rarely resting, these special little weasels are as active an animal as they come.
Whether hunting for prey underneath the snow or inside of every conceivable tree cavity or into burrows below the ground, weasels are unrelenting hunters and fascinating Minnesota mammals, as we get out and enjoy the great outdoors.