Nature Notes
Playful Otter Family Has Found Itself Good Island Home
By Patricia Martin

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

This has been a

strange winter so far.

After a "normal" first week of December with snow and cold temperatures,

the weather

changed, and it became

one of the warmest

Decembers on record.

The warmth continued through the first part of January. We were still riding bikes and waiting for the other shoe to drop. And just last week it did, with a vengeance. In fact, I'm writing this on what one meteorologist said was the coldest weekend in 10 years. So far, this has been a winter of contrasts. During the first weeks of January, I was worried because the buds on the lilac trees, and the redberried elder were really swelling. People were reporting tulips were beginning to poke up out of the ground, loons were still being spotted on the lake, and I spotted sharp-shin hawks trying to pick off birds at my feeder. Both the loons and the sharpshins should have been long gone. Well, with the return of winter, the buds stopped expanding, and the loons and hawks have flown.

There is another rather odd occurrence I began to notice late last fall. As many of you know, I go around the Island weekly to check on some of the summer cottages. While walking around one of the properties on the north end of Mackinac, I noticed a bunch of scat right in front of the barn, and marks that seem to indicate that some animals were at least temporarily living under the barn. When I next checked the property, I decided to take a closer look at the scat. Armed with a couple of twigs, I began to investigate. The scat itself looked a bit unusual. It had an overall gray color with flecks of white and dark brown and black. It was about a half inch in diameter, several inches long, and dry and flaky in texture. I used my handy dandy sticks to begin dissecting the scat, and the first thing I noticed was that there was a number of crayfish claws and other parts that seemed to make up a good bit of it. So I now knew that this animal loved to eat crayfish, but there are a number of animals that do so on the Island. I took some boards and tried to block up the hole under the barn.

The next time I checked the barn, the boards that I had placed were pulled away from the hole and moved aside. One of them was covered with what appeared to be urine and fecal material, indicating that whatever animal this was, it was still around and strong enough to move the boards. The next clue to the identity of this critter came after the snow began to fall. Though the tracks were somewhat blurred from the falling and drifting snow, some things were evident. These animals, for it seems like there were a number, were sliding down the small hill, heading toward the water. They seemed to have two sliding places; one close to the horse turnout, and about 20 feet away, closer to the house. Where the animals had been sliding, the snow was heavily packed down. The tracks then proceeded across the yard, under the gate, down the road about 20 feet, across the road, and down to the lake. The footprints of the mammal, though indistinct, were about six inches apart or more from side to side, and it seemed to be dragging a tail as there were periodically long narrow grooves in the snow. By now you've probably guessed that the animal, or should I say animals, in question are river otters (Lutra canadensis).

Northern river otters are one of the largest weasels in our area, with a total length of 35 to 51 inches, about a third of which is a long, tapering muscular tail. They weigh between 11 and 31 pounds, have short legs with webbed feet, and a long, narrow, muscular body. They're covered with a sleek waterproof fur that is rich brown along the back, grayish brown below, and is touched with silver about the throat and muzzle. This fur has been greatly valued over the years, and was the only pelt similar in value to the beaver during the height of the fur trade on Mackinac. The ears of this weasel are small and inconspicuous, and it has long whiskers about its face.

Given its name, most people would assume that river otters only live near rivers. This is not the case. They also use streams, ponds, and lakes if they're clean enough. They seem to like waterways with steep banks, though this is not always the case, as we see here on Mackinac. The homes of these animals are usually a subterranean chamber, which is connected by an underwater entrance to an adjacent stream or pond, but they don't like to build their own. They often take over old dens of muskrats or beavers. On Mackinac, this proves to be unlikely, as there are few muddy banks near the lake, and digging in our rocks to make a den would be a lot of work. So here, the otters have found alternatives; in this case, under a barn near the water, and more than likely in structures under the docks, as these animals are commonly seen in Haldiman Bay.

River otters are generally night foragers throughout the year, on land or in water, and if you look at their sharp tearing teeth, you could guess that they're carnivores. They can swim up to seven miles per hour, diving to depths of 60 feet in order to catch their prey. Their favorite fish are minnows, carp suckers, darters, and sticklebacks. Occasionally they will take game fish such as trout, perch, and sunfish. In and out of the water, they will also eat crayfish, clams, amphibians, and small mammals.

Otters, like many in the weasel family, exhibit delayed implantation. This means that after they mate, the fertilized egg will not implant in the female until the temperature and day length is right. This means that their gestation period is between 270 and 380 days, and it guarantees that the young will be born in the spring, usually in March or April. This helps ensure that there will be food available when it's needed for the two or three kits. The female usually mates again soon after giving birth. The young sometimes leave their families in the fall; however, it is more common for them to hang around until spring.

Keep your eyes open for these fun-loving weasels. It is not uncommon to catch them sliding down banks or hillsides on snow, ice, or mud. Even on flat land, they like to slide if it's slippery enough. They often take about three strides, jump head first, and slide on their chest and belly. On snow they will slide up to 10 feet, and on ice more than 20.