The River’s Otters

We see otters on the Salmon River quite often, but their visits are not predictable. We simply must be looking at the river at the correct instant. Sometimes, it is just a passing male. Sometimes, at the correct season, it is the female leading a litter of juveniles. Anywhere from one to three.  Once when she was guiding three, the smallest one, could not maintain the upstream pace. All the juveniles were vocalizing but the one little laggard was insistently squeaking a loud, persistent signal that it could not keep up. The female and the others gave it no break. It simply had to find a way or fall behind.

The otters are the largest of the mustellid family that visit us. Mustellids are musty and more. They have a strong characteristic smell. The other large mustellid that lives nearby is the Fisher, which has nothing to do with fish and stays mostly in the uplands away from water. How this 10 pound weasel was named ‘fisher’ is unclear but probably related to the European ‘fitch’ that was ‘fiche’ in French. Fishers returned to eastern Ontario when continuity of woodland habitat returned and Fishers were able to reinvade both from Algonquin Park and from the U.S. Adirondacks according to DNA tracking.

The other weasel that does fish is the much smaller mink that hunts both in the water and along the shorelines but is not an adept underwater hunter like the otter.

In late winter when the ice had formed as far downstream as the current would allow, three otters took up station along the ice edge. They were diving for green frogs. Green frogs  (Rana clamitans) are the very large frogs that often are confused with bullfrogs. The green frogs spend the winter shallowly buried in the mud of the river bed. Apparently the otters are able to find them. Sitting on the ice edge, it was clearly the large green frogs that the otters were munching.

One midsummer day as I sat in my kayak in the weedy edge, I noticed movement of the aquatic plants at the margin between the emergent shoreline plants and the largely submerged aquatic of the deeper water. After a long watch, the movement of the plants came closer to my boat. It was a half-grown otter stalking fish in among the aquatic plants. Otters certainly do eat fish but that is not their only prey

Otters stay active all winter, on the ice, in open water areas, under the ice, along river corridors and overland between rivers and lakes. They easily climb steep wooded hills and slide down the other side as they connect all the waters together in the wooded matrix that supports the landscape.

Because otters use all the major components of the landscape and do it in all the seasons, their presence enriches an area. They are important indicators of the ecological integration of processes and diversity. If we have otters, we have a rich and functional ecosystem at the landscape scale.

Written by: Gray Merriam