RIVER OTTERS ARE IMPRESSIVE ANIMALS
The last time I wrote about otters I stated that sea otters are in my top 10 list of “most appealing adult mammals.” First, they are engagingly cute, especially when floating on the ocean’s surface on their back while opening an abalone shell by pounding it against a rock balanced on their belly. Second, they have the densest fur among all mammals (more than 1 million hairs per square inch!), which allows air to be trapped for insulation and lets them float with ease. I once rubbed my hand over a sea otter pelt; it was the softest fur I have ever felt. The third reason for my admiration is because of their resilience. Sea otter pelts were once considered the most valuable in the world. Yet despite unsustainable harvesting that began in the 1700s and lasted until the early 1900s, this marvelous species survived.
But one need not visit marine waters of the West Coast or Alaska to see a close relative that has comparable credentials in the appealing-looks department. The North American river otter, native to inland freshwater habitats, indisputably qualifies. I have a fond memory of being knee-deep in a stream when I encountered a mother otter and three babies. The babies stood up in the shallow water and looked at me, turning their heads sideways in an inquiring manner, looking first at each other and then back at me. They were cuter than puppies.
River otters are also survivors that endured the unmitigated fur trapping assaults of earlier times. Today they can be found from Texas, up the East Coast and across the Great Lakes and most of Canada to Alaska and down to California. They inhabit streams, lakes and ponds throughout their range and are relentless predators of aquatic creatures including fish, frogs and snakes. My grandson recently watched one swim under a log in a stream and come out with a small turtle in its mouth. Its next meal was a large crawfish. Otters do not hesitate to travel overland to find a new hunting ground.
As with most wildlife, river otters have no interest in being seen by humans. Their history under our watch has not been a good one. But their presence in an area is sometimes detectable in another way. A sure way to know that river otters are around without actually seeing one is to find one of their latrines, which they return to on a regular basis. Otter latrines do not smell bad and are not repugnant in any way. They usually consist of a pile of crushed mollusk shells, crawfish claws and fish scales, along with a few small bones.
River otters can have negative impacts on other animals. One example is a large population of common snapping turtles that was studied for more than 15 years in Canada. Powerful mouths and sharp claws provide these heavy-shelled wetland denizens with an effective defense, and most predators know better than to trifle with snappers. But they have an Achilles heel. Like most reptiles, they become almost immobile in cold waters, especially beneath the ice of a northern lake. Over a 2-year period, the number of adult snapping turtles in the population was reduced to a third of what it was formerly. River otters, indicted as the culprits, killed and ate the helpless snappers during the winter. Likewise, during research at the University of Georgia’s Savannah River Ecology Lab, Kurt Buhlmann reported the death of numerous eastern chicken turtles killed by a family of river otters in a seasonal wetland. According to Kurt, telltale gnawing marks encircling the shells of dead turtles were the giveaway for who the perps were.
A river otter is one of the coolest mammals to find in the wild and a delight to watch. Of course, potential prey swimming around in the same waters would not consider the river otters cool or delightful. It’s possible some turtle biologists might feel the same way.
