North American River Otter - Lontra canadensis
Description: The River Otter is a semiaquatic mammal with a long body, short legs, and a tail that is about one-third of its body. They are a part of the weasel family. Otters weigh between 11 and 31 pounds, and can reach up to 42 inches. They appear contrasting browns in color- their underside a lighter brown than their top side- and they have have short, water-repellant fur that aids them in their swimming abilities. Their strong tails also help them swim, as well as their webbed feet.
Habitat: River Otters can be seen in rivers, lakes, or estuary ecosystems. Although they spend a lot of time in the water, they can also be seen on land- hence why they are semiaquatic mammals. Their homes are burrows with many channels and openings for entry and exit, and are located by the water's edge.
Range: North American River Otters are found on the coastal parts of North America, as well as throughout Canada and Alaska. Their range has been grately affected over the years due to habitat loss.
Ecological Notes: Otters are a top predator, mostly feeding on fish, but they also feed on amphibians, turtles, crayfish, and oysters. To feed on things like oysters, Otters will often grab a small rock that they will place on their stomachs while floating on their backs, and then proceed to smash the oyster against the rock to break it open. Reproduction is the only time that male and female otters will interact with one another. They are polygamous animals, meaning the male will have multiple mates during the reproducing season. The female Otter can deliver up to 6 pups in the den. When these pups are about 2 months old, the mother will then push the babies into the water so they can learn how to swim. Males do not take care of the young. Otters can live to be over 20 years old in captivity, but usually only live to be about 9 years old in the wild.
Personal Information: On the 2014 Marine Bio North Carolina Field trip, we had the chance to go to the North Carolina Aquarium where I found this River Otter. There were two otters in the exhibit that were very active- running around on the land portion of the exhibit, as well as swimming around in the water. I was able to catch the picture seen above of the River Otter.
Baitchman, Eric J., D.V.M., and George V. Kollias, D.V.M. Ph. D. "Clinical Anatomy of the North American River Otter (Lontra Canadensis)." Journal of Zoo and Wildlife Medicine 31.4 (2000): 473-83. BioOne. Web. 24 Apr. 2014.
This article talks about the anatomy of the North American River Otter. Since journals prior to this one focused on one single anatomical part of the Otter, this article wanted to focus on multiple anatomic features. This includes a detailed physical description of the Otter like the one above, as well as internal descriptions of the Otter like their bone structure, their organ structure, and much more.
Cote, D., H. M J. Stewart, R. S. Gregory, J. Gosse, J. J. Reynolds, G. B. Stenson, and E. H. Miller. "Prey Selection by Marine-coastal River Otters (Lontra Canadensis) in Newfoundland, Canada." Journal of Mammalogy 89.4 (2008): 1001-011. BioOne. Web. 24 Apr. 2014.
This article talks about the Otters diet in Canada. Researchers wanted to track the kinds of fish that the otters ate, and wanted to see if there were any trends in what he Otters ate in response to prey availability. Between the two bays that the Otters were studied in, the researchers found that certain fish were eaten in the specific areas, and only one type of fish was important in both bays for the Otters. They also were able to see trends in what the Otters are when fish availability changed.
Contributed by Julie Bontempo - 2014