Animal Sighted Strolling Downtown Was Likely an Ermine Nature Notes By

Patricia Martin

One thing I particularly like about writing this column is that it inspires people to call and let me know about unusual natural sightings or encounters. Recently, a friend telephoned to let me know about another spotting of the Golden Eagle and then proceeded to relate an amusing tale about an animal he saw downtown. Apparently he was walking down the main street, when he noticed a small, low, dark brown animal, about a foot long, with a furry, relatively short tail and short legs. It casually loped down the road. He looked around, but no one else appeared to notice this animal.

From his description, it seemed evident that he had seen one of the members of the weasel family, the Mustelidae. This family includes, in addition to all of the weasels, the badger, wolverine, and various skunks. Members of this family appear in the fossil record about 34 million years ago and today can be found on all of the continents except Australia and Antarctica. There are about 70 species in this family of carnivores.

Ermine

In general, the mustelid have long thin bodies and short legs. Their feet are five-toed with nonretractile claws. The males are usually 10 to 25 percent larger than the females and they generally have well developed anal scent glands, particularly in the skunks.

Many of the mustelids that live in temperate climates have an unusual reproductive strategy, known as delayed implantation. Fertilization occurs soon after copulation, but the embryo doesn’t continually grow. It doesn’t immediately implant into the uterine wall but remains a small cell mass (blastocyst) until the day length is right and it will then implant and normal development will continue. This “resting” period can be up to a year depending on the species. Often implantation occurs so that the young can be born in the spring when conditions are most favorable.

In the Great Lakes Region, there are 10 species of Mustelids and a number of those are on Mackinac. The largest weasel that inhabits the Island is the River Otter ( Lutra canadensis ), frequently seen in the harbor and along the shore of the Island. These animals are usually 35 to 51 inches long, and so, obviously, not the animal my friend saw in town. Skunks and the badger are also eliminated as possibilities, as they don’t match the description and are generally not found on the Island. The American Marten ( Martes americana ), minks ( Mustela vison ), and the fisher ( Martes pennati ) are too large to be the animal sighted (martens and minks have been seen on the Island). There are two species that generally fit the description. One is the Long-tailed Weasel ( Mustela frenata ) and the second is the Short-tailed Weasel or Ermine ( Mustela erminea ). Because of the description of having a relatively short tail, it is most likely that what my friend saw was an Ermine or Short-tailed Weasel.

When most people think of the Ermine, they think of a white-with-black-flecked fur stole attached to a sovereign’s robe. This is the winter coloring of the Ermine. When the day length shortens and the temperature cools off, this weasel turns white except for the tip of its tail, which remains black. The summer coloring of the Ermine is a rather uniform dark chocolate brown on its head, back, legs, and tail near the body. The under parts are white and the last third of the tail is black. The total length of the Ermine is nine to 13 inches and its tail is two to four inches long. It weighs only about two to six ounces and has the typical weasel-like build. The Long-tailed weasel, by contrast, in the summer is more of a cinnamon brown and generally larger, being 11 to 17 inches in length and weighing in at three to almost 10 ounces. The tail length is probably the most distinguishing characteristic and is usually 3.5 to six inches long, more than 44 percent of the head and body length.

The Ermine is a ferocious carnivore, which lives in a variety of habitats, including open forests, riparian woodlands, and shrubby fencerows. It is a territorial beast with the males having a territory of about 63 acres and the female about half the size. Male and female territories can overlap, but members of the same sex will fight if they encounter each other in their territory. Like most of the weasels, they patrol their territory, marking it with secretions from their large anal glands. It may take an Ermine up to two weeks to patrol its whole territory. Within their land they establish several nesting sites near good hunting grounds and they build their nests in rodent’s burrows, hollow logs, or under a rock. The nests are lined with grasses, leaves, and with fur from unfortunate prey. The young are born in the spring, with a 280-day gestation period including an eight- to nine-month implantation delay. Four to eight young are in a litter. The female young will reach adult size at about six months of age and will mate after only two to three months. The male, on the other hand, doesn’t gain his full weight until his second summer, when he will breed.

These are animals who usually hunt at night, though they will also forage during the day, especially in the winter. Their favorite food is rodents, with mice, voles, and shrews making up three quarters of their diet. They also eat rabbits, squirrels, birds, and other vertebrates. They hunt by zigzagging through an area poking their heads under forest plants and into underground tunnels. When prey is spotted, they approach it slowly at first and then grab it in a quick rush. The weasel will then wrap itself around the prey and dispatch it by biting it on the head or neck.

Though these are extremely aggressive animals, they’re often prey to larger carnivores such as red fox, coyote, martens, and fisher. Hawks and owls will occasionally grab an Ermine, but historically mankind has been the biggest predator, trapping thousands of them in a single season. Demand for their pelts, however, has decreased in recent years.

If anyone saw this weasel in town, or anywhere else, I would be delighted if you would let me know.

P.S. If you haven’t noticed, the fall mushrooms and fungus have come up with a vengeance following the last few rains. One friend found Black Trumpets among other edible fungus.

Trish Martin is a year-around resident of Mackinac Island, has earned a master’s degree in botany from Central Michigan University, and owns Bogan Lane Inn.