Sewellel (Mountain Beaver) - August Morning, Mount Rainier, Washington
Neither a beaver nor a high-mountain dweller, the sewellel is a rather singular animal. It’s the last living member of a once-successful family of rodents called the Aplodontiidae. The sewellel is a “living fossil,” showing primitive skeletal features that other rodents have lost. Its kidneys are also unusual: they are inefficient at maintaining the body’s water balance. Thus the sewellel needs to live close to water so it can drink a lot—a third of its weight in water per day.