December 5, 2011

Otter Watching

By Dave Erler

As winter approaches we sometimes think the best times to view wildlife are on hold until spring arrives. That is true for birds that migrate and cold-blooded ectotherms like reptiles, amphibians, and insects, but the ice and snow help us catch a look at a few animals. River otters are one of these and as well as one of my favorite mammals to watch.

I am fortunate to be able to walk out my front door and within five minutes, get to the three spots that offer excellent viewing opportunities. The first is along a stretch of a good-sized brook where I built a bridge, another is at an old millpond, and the third is from a 40-foot cliff overlooking a beaver pond. Being a morning person, I usually spend a half hour to an hour every morning checking those spots. If I am lucky I might see an otter once every two weeks during the warmer months, but come late fall and winter I can almost count on seeing at least one otter every week.

Why do we see otters more in the winter? I think there are several reasons. The ice limits where otters can pull out of the water, which they need to do periodically to rest, shake their fur out, or eat something too large to handle in the water. Open water along streams and especially where ice has formed shelves along the edges are good places to see otters, as are areas just below and above beaver dams. With the white winter background, they stand out on as opposed to the summer when they quickly disappear in the vegetation.

Another reason has to do with what they eat. The carnivorous diet of otters includes fish, crawfish, frogs, tadpoles, and occasionally birds and small mammals, including muskrats and young beavers. By checking the scat that otters leave in latrine sites on land close to shore I find clues about what they eat. Most of the scat or spoor I check shows evidence of fish scales and crawfish legs. In the summer, when I have seen otters eating, they consume small fish and tadpoles quickly as they surface in the water. In the winter, I see otters on top of the ice eating larger fish, larger frogs, and occasionally turtles. The ice-cold water causes some fish to slow their metabolism, making it easier to catch them. Frogs and turtles are dormant and buried in the mud during the winter; the otters excavate them from the bottom while they hibernate. Several times, using a long fallen branch, I retrieved painted turtles that otters left on the ice. I know the otters have to eat to live, but I have to admit that I feel a little sorry for the turtles. When otters pull painted turtles out of the water, the turtles are tight in their shells, but otters are still able to chew off the legs, tail, and sometimes the head, leaving the rest of the turtle with only teeth marks on the shell. Because the painted turtles are in a state of hibernation, they might not have much feeling, but those that still have their heads are no doubt alive. In cases where I find those painted turtles with heads intact, I put them back in the water, but I doubt very much that they survive. Without legs, these turtles have virtually no chance to swim or to burrow into the mud. I did find one large snapping turtle that an otter had caught. Because snapping turtles have a very small plastron (bottom shell), the otter was able to eat most of it.

So have I seen any otters lately? In the last week, I was fortunate enough to see at least four different otters on three occasions. The first was a small otter, clearly a youngster. It was busy porposing through the water in pursuit of something when I lost sight of him around a corner of the millpond. The second one was on an ice shelf in the same pond eating an 8 to 10-inch pickerel. The last two I saw when I was up on the cliff overlooking the beaver pond. Two yearling otters put on a great show. When I first saw them, they were spinning and splashing around and around in the water about six feet from the near shore. I caught a brief glimpse of something in one of their mouths. They appeared to be fighting as they spun around in the water for a good two or three minutes. One apparently swallowed what it had its mouth. That done, the otters ceased the skirmish and both beached themselves. They proceeded to roll around in the snow, followed by a brief mutual grooming session, and then back to chasing each other and finally back through the sedges and eventually into the water, where I left them swimming off toward the beaver dam.

If you want to see a wild otter, keep checking those places where open water meets the ice. You might get a chance to watch an otter, an experience you’ll long remember. And, if you can’t wait to see an otter in the wild this winter, make a reservation to check on the Science Center’s otter exhibit on one of our weekend “Wild Winter Walks.” Good luck otter watching.

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