By Ana Weidenfeld
The American Beaver (Castor canadensis) can be found in streams, marshes, lakes and ponds throughout most of Canada and the United States, excluding Florida, much of Nevada and Southern California. Known for its flat and wide tail, the American Beaver is also distinguished by its rotund rodent body and four-inch front teeth. You can tell the beaver apart from similar-looking rodents like the Muskrat and Nutria by noticing the creature’s habit of munching on logs.
So what are beavers up to with all of those logs? Beavers use logs to eat and to build dams. Dams allow beavers to access higher branches and to make pools. Beavers are meticulous homeowners and are constantly listening for leaks that form in their dams. Highly territorial animals, beavers would gladly hang a “No Trespassing” sign on their dams if possible.
Beavers are remarkable swimmers and can stay under water for 15 minutes. These chubby rodents have a layer of fat underneath their silky coats that keeps them insulated even in icy water. They maintain their fur by combing in the waterproofing oil castoreum, which the animal naturally produces from scent glands. Their plush fur was once widely coveted for fashion and the species suffered from overhunting well into the 20th century.
Now recovered, the American Beaver is thought to mate for life. After a four month gestation period, the adorable kits are born in the summer–already covered in fur. The kits emerge with eyes wide open and weighing around one pound, taking to the water within half an hour of birth. After a week they are proficient swimmers but if they do get tired they can always catch a ride on mom’s back.
Some people consider beavers to be a pests because they eat trees used for timber and their dams can harm agricultural fields and roadways. However, these furry swimmers are in fact quite important to overall ecosystem health. By opening up the area around a pond or stream, beavers facilitate a radical increase in biological activity. Sunshine allows aquatic plants and algae to flourish, which attracts a host of microorganisms. This microbial activity draws in invertebrates and consequently fish like trout and smelt, birds such as ducks, and mammals like mink. Beaver dams also protect downstream areas from sedimentation and work to detoxify runoff and reduce erosion as well.
If you are in the mood to watch these fastidious and fun mammals at work, head into Martinez. The beavers are nocturnal, so make sure to bring your flashlight and go out in the early morning or late evening hours.
Photo credits (from top): Kansas State University, Ginger Holser, J. Robert Sewall.
