The River Otter (Lutra canadensis) is perhaps one of the most cosmopolitan of any North American mammal, yet it is rarely seen. It is found from Florida to Alaska, the south-western U.S. to Hudson Bay and the Maritime Provinces. It is found in every continental state, plus Alaska, and virtually all of Canada wherever fresh water is found. The otter spends its life in and around water and is superbly adapted to an aquatic lifestyle. Rivers, lakes, millponds, streams and wooded swamps are its domain. Although I have spent a lifetime mucking in and around such places, it is a rare treat to catch a glimpse of one. Personally I have seen them in the inland bays, several local millponds, and the wooded swamp between Haven Lake and Abbott’s Pond. Their movements are so fluid that they literally seem to flow over the roots, fallen trees and bases of swamp trees. One instant you see them and the next they have disappeared.
Otters are constantly on the move hardly pausing for a quick nap, except during the time when pups are present, moving along a regular range of perhaps 15 miles. Locally travelling from the Mispillion River, thru Silver Lake, across Route 113 into Haven Lake (road killed otters have been found at the dangerous crossing of Route 113 between Silver and Haven Lakes, Milford, DE.), crossing Meadowbrook Lane into Johnson’s Branch wooded swamp, eventually into the Lee Pond and Abbott’s Pond. Further travelling into the Jeanette Isaacs Swamp and across Route 36 thru the Kenton Woods to the Isaacs-Greene pond, crossing Apel’s Road into the tax ditch, continuing onward to the very source, then reversing the route to the point of origin. However, sometimes even the uppermost regions are not enough and the otter will travel great distances overland to another watercourse.
Once while visiting my brother, who lives about one half mile from the village of Staytonsville, we were called by his neighbor to identify the creature that her dog had at bay in her backyard lily pool. Before I saw the animal I was convinced it would prove to be a muskrat since her home was situated at least three quarters of a mile from the nearest stream. I was greatly surprised to find an adult otter in the center of her lily pool. Her dog seemed to be itching for a fight but, probably lucky for the dog that never happened. According to Ernest Thompson Seton (Life-Histories of Northern Animals), a fight between an otter and dog usually results in the death of the dog by drowning. Seton also states that the bite of an otter is powerful enough to crush a hound’s leg bone in its jaws. The otter is a large member of the weasel family that includes the weasels, mink, marten, fisher, and the wolverine.
The otter’s den (or bolt, an archaic term for an otter’s den) is usually dug into the bank of a pond or stream with the entrance below water, as is also the habit of the muskrat. Sometimes a second entrance is dug above the water level, after the young are older and can frolic outside. Uprooted trees and stumps may be utilized for nest sites as well. The nest chamber is softly lined with twigs and grasses. The two to four pups are born blind in April (or early May). They are not fully weaned until about four months old. They stay as a family group until the next breeding season and are often seen together. During this time they keep up a constant chatter of communication with each other. If a naturalist is very quietly canoeing or kayaking the twists and turns of a pristine wooded swamp, many times the vocalizations are heard before the otters are seen. (They should never be disturbed or approached in any way. The lovely photos of local otters in this article were taken from a distance with a powerful telephoto lens by my daughter, photographer Beth A. Baker).
Otters feed on fish, crayfish, snails, frogs and other aquatic invertebrates. One friend of mine, whose home is situated on the shores of McCauley’s Pond, related to me that he is often alerted to the presence of otters by the sound of bones crunching, since the otter consumes its meal,, bones and all. Knowledge of this fact is useful to differentiate otter scat (excrement), with the presence of fish bones and scales, from similar scat of beaver and muskrat which are entirely vegetarian.
So how can you increase your chances of seeing an otter?
1.- Stop frequently at the boat ramps of local millponds and spend several minutes carefully scanning the water surface for heads. Otters are rich brown above with silvery counter- shading below. They have small ears, broad snout, and prominent whiskers. They can be as much as four feet in length and can weigh ten to twenty pounds. Keep in mind that an otter can easily stay submerged for three or more minutes and swim a quarter of a mile before surfacing.
2. - Learn to identify otter sign. Scat containing fish bones and scales, or sometimes the shells and claws of crayfish and snails. Learn to distinguish otter tracks from beaver, muskrat, raccoon, and domestic dogs. (A Field Guide to Animal Tracks, by Olaus Murie, The Peterson Field Guide Series, is wonderful for this).
3. - Use silent watercraft such as canoes, kayaks, or electric trolling motors. Get out and explore the back waters and swamps. Be observant.
4. - Invest in a good pair of binoculars and learn how to properly adjust them.
5. - Networking and word of mouth. Keep in touch with other naturalists.
6. - Join the Delaware Nature Society and take part in their programs, take advantage of their knowledgeable staff, and partner with them in their habitat preservation activities; ask questions.
Remember: Otters are always moving; Here today, gone tomorrow.