ISTOCK PHOTOS/GERALD CORSI
ANDI SEDLACEK
The North American river otter (Lontra canadensis) is active year-round near waterbodies where food is available.
Otters? In Wisconsin? You betcha! They’re everywhere — they've been documented in every county throughout the state. But we’re not talking about the sweet, cartoon-eyed otters who hold hands while sleeping. We’re talking river otters, which are so elusive they’re rarely caught on trail cameras. KNOW YOUR OTTERS River otters spend a lot of time in the water, which is why these semi-aquatic critters are difficult to detect. They live near lakes, rivers, streams and wetlands, crossing dry land to get from one body of water to another. River otters stick around areas of water with a reliable food source and mainly eat fish like carp and suckers. But they’re opportunistic eaters, so they’ll also eat shellfish, crayfish, amphibians, reptiles and even small mammals like muskrats. Basically, they’ll take what they can get when it comes to food. Though river otters are primarily nocturnal, mostly active at night, they can be seen during the day, which is when they go out and about to eat. River otters are often mistaken for many other furbearers like fishers, weasels and mink. Of those four animals, river otters are the largest, weighing 10-30 pounds and measuring 3-4 feet long, including their tail. They can run pretty fast, up to 15 miles per hour, and can slide even faster — remember, they're semi-aquatic, so they're often wet. Their webbed feet and long, muscular tails help them navigate water masterfully.
26 wnrmag.com
ALL-SEASON ANIMAL Every season is the season of the otter; they’re active year-round and breed annually. River otter pups, also called kits, are generally born in the early spring in litters of two to four. Breeding season begins again soon after that in April and May. Otters have a unique breeding strategy involving delayed implantation, which also happens in other animals like black bears, weasels, bats and kangaroos. After breeding, there is a period of about 10 days when a blastocyst, or ball of cells, forms and then cell division stops. The blastocyst, which also can be thought of as an embryo, won’t implant in the female’s uterus and will remain dormant in her body through summer and fall. In the winter, the embryo will then implant and continue to grow and develop, and the female otter will be pregnant for two or three months. When spring rolls around and more food resources are available, the river otter pups are born and the breeding cycle starts again.
