Betty Boucher, age 13, of Fredericton, New Brunswick, Canada, for her question:
WHY DO BEAVERS HAVE FLAT TAILS?
Although you can find beavers in Europe and Asia, there are more in Canada and the United States than anywhere else in the world. North American hunters trap more than 500,000 each year since their soft fur is much in demand by the clothing industry. Both the U.S. and Canadian governments now protect the beaver and hunting is regulated.
Beavers in North America can be found along rivers, streams and in many freshwater lakes near forest areas. They are excellent swimmers and can travel underwater while holding their breaths for periods up to 15 minutes.
Measuring three to four feet in length and weighing 40 to 60 pounds, the beaver is the world’s second largest rodent, being topped in size only by the South American capybara.
Our beaver friend’s tail is his mark of distinction. About seven inches wide and a foot in length, it is flat and extremely stiff. A small part near the body is covered with fur but most of it is covered with black, scaly skin that has only a few stiff hairs.
Interestingly, the beaver’s tail serves as a prop when the animal stands on his hind legs to cut down a tree or to eat. The three point arrangement makes the beaver extremely sturdy in his standing position.
The flat tail is also used very much like a rudder when the beaver is swimming. Steering is made easy this way.
Another useful feature of the tail is that it serves as a signaling device. To indicate danger, the beaver will slap his hefty tail on the water to make a loud noise which warns his beaver friends.
The beaver’s teeth are also noteworthy. There are 20. The four in front are used for gnawing tree branches and trunks. Called incisors, the front teeth have a bright orange covering that is very hard. The incisors constantly wear down, but they continue to grow throughout the beaver’s life. Folds of skin, one on each side of the mouth, turn inward and meet the incisors. These flaps seal off the back of the mouth so that when the beaver gnaws on a branch, chips of wood and splinters will not get into his mouth. The flaps open when the beaver drinks or eats.
Have you ever heard the expressions “eager beaver” and “busy as a beaver”? These sayings came about because the animal is always working. He never seems to take time out just for relaxing. It’s always a heavy schedule of toil for this enthusiastic worker.