North American Beaver (Castor Canadensis)
Photo Credit: Steve Hersey http://www.flickr.com/photos/sherseydc/with/729358429/
The north American Beaver is the largest rodent in North America. Because it is semiaquatic, it has webbed hind feetand a flat paddle shaped tail, both of which are clearly evident in the photo. The front un-webbed paws have claws. Nictitating membranes cover their eyes for vision underwater. Their ears and nostrils close while submerged. They can remain under water for 15 minutes. They construct dams in waterways to regulate water levels where their lodges are built. Wood is not only used for their dams and lodges but as a food source including birch, maple willow, alder, red oak, & ash. Their dams may cause localized flooding but the creation of ponds, wetlands, & riparian habitat makes them a keystone species that increases biodiversity. Not only do aquatic plants colonize these areas but invertebrates, fish, & birds benefit.