While assorted species of otters live on all but two continents, the only species we have in Iowa today is the North American river otter. These chummy, playful mammals are characterized as clever and mischievous, but there’s a lot more to an otter than that!
Fore!
Otters, like chimps and humans, have been commonly seen using objects as tools. One of their favorite tools is a rock, which they can use for crushing or prying open bivalves like clams and mussels. Although behavior this is particularly common in sea otters, who will take a good rock with them out to open ocean, North American river otters will occasionally use and keep certain rocks as well. To the dismay of golfers, these otters also think golf balls make fantastic toys and will occasionally snag a few off the course to take home.
Sink or Swim
Female otters rear their young without the help of the male in an underground den, usually one abandoned by a previous resident like a beaver or badger. Otters generally give birth to a litter of one to six pups, and their family ties will remain strong until the pups reach full adulthood. But first, at the tender age of two months, the pups take their first swim whether they like it or not. The mother otter pushes them out of the den and into the water, where the pups flounder a little and instinctively learn to swim while she supervises. Group lessons and interactions like this are common with otter pups and mothers, and this playtime helps the pups learn survival skills.
Slip and Slide
Play continues as young otters mature, and in some surprising ways. Otters will build a slip-and-slide of sorts on river banks they frequent, repeatedly running up the hill, sliding down, and popping out of the water to shake off and chirrup at each other (as a side note, otters are known for a lot of varied verbal communication). Their long, streamlined bodies are ideal for this sort of fun, and they seem to enjoy it immensely. Sometimes they’ll even build these slides into a snowbank when the weather gets colder. This is thought to help the otters practice making a quick escape from land-dwelling predators like coyotes.
No Rabbit Food for Me
While many people think that otters would eat grass and water plants, that’s not the case. Otters are carnivores, with North American river otters dining primarily on fish and some invertebrates like crayfish and mussels. They will also eat small mammals like mice, chipmunks and moles, and even birds if the opportunity arises. This is logical based on the diets of their closest relatives: weasels, mink, badgers, wolverines, and ferrets are all generally carnivorous too. Beavers, on the other hand, are part of the rodent family and are not closely related to otters.
Pretty Pelt
Otters, like beavers and many other furbearing mammals, were trapped extensively in North America by early trappers. Native Americans also hunted these animals heavily in order to trade their pelts with these settlers. Otter in particular was considered very fashionable and fancy, and thus was used for everything from hats and coats to tie pins and belts. Overharvesting, pollution and habitat loss wiped out the Iowa population, but reintroduction efforts started in 1985 and the population has been steadily climbing ever since. Otters are no longer threatened in Iowa, have been seen in every county and the population has stabilized.
Talk to the Tail
Otters can grow to be surprisingly large. It’s not uncommon for otters to approach five feet in length, but over a third of that length is generally tail. Why is it so big? Otters use their tails like a rudder as they swim, and it needs to be muscular to do this job. Occasionally otters have also been documented as using their tails for self-defense, swinging it at a predator as they retreat.
Foreign Folklore
In some Native American traditions and Japanese folklore, otters have a crafty role similar to that played by the fox in Anglo-Saxon traditions. In Celtic and Norse folklore the otter is presented as knowledgeable and helpful, and the literal translation of the name is close to “water dog.”
Call it What You Want
A group of river otters can be called a lot of different things, including a bevy, a romp, a family, a lodge, or if they’re in the water, a raft. This last term is most used for sea otters, which hold on to each other to prevent drifting apart. Perhaps the cutest form of this behavior is when two sea otters appear to hold hands while floating on their backs, which they will do to prevent losing each other while sleeping. North American river otters are not documented as displaying this behavior, as land and the family den is usually nearby.
For more on Iowa’s critters, check out our Iowa Wildlife board on Pinterest.
