I worked in the Grand Kankakee Marsh County Park for over three months before I finally saw the infamous family of river otters that had made a home about sixty yards away from one of the park’s duck blinds. Notice I say infamous, not famous.   

When people think of river otters, they think playful puppy of the sea. Energetic, enthusiastic, shooting back and forth in the water in tight, acrobatic circles. Or hopping above ground with tiny, hurried steps toward prey (You might think urchins on the belly too, but that would be a sea otter, not a river otter). Those images are all true.

That combination of skills makes them one thing: predators.  River otters were born to kill, and they kill well. Like several species, including house cats, river otters sometimes kill no apparent reason, especially if the food is plentiful and weather tolerable. Their extra energy is spent playing with one another in North America’s rivers, but also in tearing the shell from a snapping turtle or pouncing on a molting duck.

River otters represent one of the most fundamental questions in modern conservation: is returning a native species to its historical territory always a good idea? In this case, the fur trade, along with a loss of habitat and pollution, decimated the river otter population until the 1970s, when efforts to reintroduce the species began.  At that time eleven states river otters called home no longer had any, and nine additional states had minuscule populations.  Repopulation efforts have been very successful, even prompting a return to trapping the species for its prized fur (the densest of all fur trade mammals). 


This return to its native lands has had a cost. In some locations, nature was able to “close the gap” and maintain equilibrium without the presence of the predatory otter.  Simply bringing them back into the mix upset this adapted balance. Most of the otters’ chief predators, save foxes and coyotes, have also vanished from many waterways, giving this voracious species an unnatural advantage.

Conservationists must ask themselves serious questions in relation to the river otter and other reintroduced species: Is the primary task of conservation a return to a previous natural state before human intervention; or, is it to maintain the current, sustainable balance of nature?

Want to Know More?

Here’s a thorough article from the Smithsonian National Zoo on the North American River Otter. About as concise and well-informed as you can get.

The US Forest Service released this fantastic study on conservation effects, efforts and strategies for the North American River Otter.