EPOW - Ecology Picture of the Week

By Any Name Not a Beaver

Nutria or Coypu (Myocastor coypus), Family Echimyidae
"Pond 217", Tigard, Oregon USA

Explanation:  Beaver!  Wait, is it?  No!

This is the beaver's evil twin, known as the nutria or the coypu.  It is a nasty invasive species that has spread from coast to coast in the continental United States and beyond.  

They may look like beavers, and are aquatic like beavers, but they are just gigantic rodents (Order Rodentia) that can grow to 20 pounds (9 kg).  They can outcompete the native beavers muskrats, consume native prey, decimate local native vegetation, and wreak havoc on aquatic waterways wherever they occur ... breeding like, well, like rodents.  

They are native to southern South America, but were introduced into the U.S. in the 1930s for fur farming and to control aquatic vegetation.  They did their job all too well.  And are yet another example of introducing organisms that take over natural ecosystems.  
 

Nutria are mainly aquatic, and flee to the safety
of their pond or stream when approached.