Wednesday, March 16, 2011

Wildlife: Nutria/Coypu


This is, apparently a Nutria, also known as a Coypu. I wasn't familiar with this animal at all until this weekend. We initially thought it was just a muskrat, but facebook friends helped me identify it as a Nutria. As you can see in this picture, nutria have orange/red incisors and a long skinny tail. The water in the Willamette was very high this weekend and we found this guy right along the shore when we went for a walk around the river.

I love learning about knew things, so once I found out what this was I read what I could find about it. The Nutria is actually an invasive species. They were brought to the US for their fur, in Oregon the peak of the trade was between 1930 to 1950, topping out at about 600 fur farms. When the market for that fur declined many were just released. They've been seen in 40 states in the U.S. and there are known, established populations in at least 15 states. In Louisiana and Maryland the Nutria populations have done severe damage to wetlands. They feed on plant roots, having a significant impact on above ground biomass. I found one article mentioning a farmer loosing a cow to a pit caused by their eating habits.

I found this site on the subject, from the Center for Lakes and Reservoirs at Portland State University, very interesting. According to their report from 2007 there's currently no management plan for these guys. It also noted that the Pacific Northwest is unusual in that there is a high density of nutria in urban areas, and populations spread in mild winters. There are really no major predators in the northwest, in their native South America they would be eaten by alligators, large dogs, birds of prey. Fortunately they mentioned that there is a lot of awareness of the problem here, and I'm sure sighting one isn't that unusual within Portland. 

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