Otter Slides By Judy Berg

 

When an otter slides down an embankment of snow or mud or across the ice on a waterway, it holds its front feet back along its sides with its hind feet out behind in a "streamline arrangement" (Murie, 1974). Tracks will be found at the beginning and end of a slide, unless it leads into the water. When an otter traverses level ground through heavy snow, it moves itself by pushing with its feet held underneath its body, so tracks will be found in this trough of snow. Otters will slide on snow and ice but also on slick mud embankments. (I inadvertently tried one of their slick mudslides. Splash!) Sliding can occur at any time of the year and has been considered a "favorite amusement" (Coues, 1877). In his book published in 1909, Seton wrote several accounts of otters being observed sliding down an embankment of snow and ice or mud. He stated that the sport was pursued by using the same slide more than once and with more than one otter engaging in the activity. John James Audubon, in the mid-1800s, wrote an account of such activities in which he observed a pair of otters sliding down a "soap-like" muddy surface of an embankment 22 times each, stopping only when they detected their human observer. This sliding behavior was written from accounts in the eastern sections of North America and southern United States (Seton, 1909). There also have been some later accounts of this behavior in these same areas, and in the midsections of the United States (Liers, 1951 and 1953; Murie, 1974). Liers, in his book An Otter's Story (1953), described a family of otters in Michigan sliding over and over again down a mud-slick embankment. He stated that they would slide down the embankment and into the water, then swim to the bank, run up to the top of the embankment, and slide down again. He said that the more they slid the wetter and slicker the slide became. (Sounds like fun!) Seton, when discussing otters and their slides, stated that "…this is the only case I know of among American quadrupeds where the entire race, young and old, unite to keep up an institution that is not connected in any way with the instincts of feeding, fighting, or multiplying, but is simply maintained as an amusement"
River Otter Slide with Embedded Tracks, Photo by Judy Berg

(1909, p. 834). However, even in this time period, the "otter toboggan" behavior was not observed, or at least not reported, in western North America. In more recent literature, this behavior continues to be rare for this part of the country (Melquist and Hornocker, 1983).


I was never fortunate to observe otters making a slide but did find evidence following the event. In most cases only one slide was detected in an area-across ice on the river, through snow on land, and on a muddy embankment-and was moving in one direction as determined from the direction of the tracks found in combination with the slide. The documented slides either led to water or appeared to be a method of movement across the ice and snow. Sliding across ice and snow in the colder climates is a means of travel (Melquist and Hornocker, 1983). On two occasions I did find indications of more than one otter making a slide. In one location I found two slides together of different widths containing tracks of different dimensions, indicating two otters. These signs occurred in snow and next to open water on the Colorado River. One slide was 6" wide with tracks 2" wide by 2 1/2" long; one slide was 8" wide with tracks of 3" wide by 3 1/2" long. All five toes were evident in the tracks. A sighting of two otters "playing" together in this location was reported one week prior to my find. In another location I found three slides together, each of a different width, indicating three otters. These signs occurred in snow and across ice of a waterway. One slide was 9" wide with tracks of 2 1/2" wide by 3 1/2 to 4" long. The slide was approximately 40 feet long then a pattern of tracks, slide, then tracks. There were shorter length slides of 8" wide with tracks of 2" wide by 3 1/2" long; then another set of shorter-length slides of 7" wide with tracks of 2" wide and 3 1/2" long. A sighting of three otters was seen in this location prior to my find. In both of my above cases the slides led to open water. I can't state from the results that what I saw was the "fun" behavior that others had observed in the above reports, but I can certainly conjecture that the otters enjoyed their adventure.

References:

Coues, E. 1877. Subfamily Lutrinae: The Otters. pp. 293-324 in Coues, E. Fur-Bearing Animals: A Monograph on North American Mustelidae. U.S. Geol. Surv. of the Terr. Misc. Publ. 8:1-348.

Liers, E.E. 1951. Notes on the river otter (Lutra canadensis). J. of Mammal. 32:1-9.

Liers, E.E. 1953. An Otter's Story. The Viking Press. New York.

Melquist, W.E. and Hornocker, M.G. 1983. Ecology of river otters in west central Idaho. Wildlife Monographs, 83:1-60.

Murie, O.J. A Field Guide to Animal Tracks: The Peterson Field Guide Series. Houghton Mifflin Co. Boston, MA. Seton, E.T. 1909. The Canada Otter. pp. 817-839 in Seton, E.T. Life Histories of Northern Animals. Charles Scribner's & Sons. New York.