North American Beaver

Common Name: North American Beaver.

Scientific Name: Castor Canadensis.

What to look for?  Not “The Angry Beavers” of Nickelodeon fame! Look for a large, brown, furry rodent. The North American Beaver has a stout body. Their body is covered with reddish-brown to blackish fur. They have a broad, flat tail that is covered with black scales and hairless. Beavers have hind legs that are longer than the front legs. And each foot has five clawed toes. Their hind feet are webbed to help maneuver in water. Beavers have small eyes and ears. As an aquatic mammal, the North American Beaver has valves that close when the beaver is under water. Beavers have large, orange incisors that grow continuously.

Where can they be found at Carillon Stonegate Pond? There was a sighting at the west Carillon Stonegate Pond – on the north bank. It was at dusk and the Beaver was near some small-diameter tree trunks that it had previously gnawed down.

How big are they? An adult North American Beaver will typically be three (3) feet to four (4) feet long. And they stand approximately one (1) foot tall. Beavers usually weigh from 25 pounds to 55 pounds.

How else do they behave? Lumberjacks! With their specially adapted, self-sharpening incisor teeth and powerful lower jaw muscles, Beavers can easily cut through small diameter trees. But they are capable of cutting down larger trees of five feet in diameter. Skilled Engineers! They are well known for their ability to modify their habitat and build lodges, dams, and canals. Excellent Swimmers! Beavers can swim approximately five (5) mph, and, with oversized lungs, they can stay submerged for some fifteen (15) minutes and travel over half a mile. Family- oriented! Beavers form strong family bonds with several generations living together.

What’s for dinner? Plant-based food! North American Beavers are herbivores. What they eat depends on what plant species are available. Beavers eat bark and cambium - the softer growing tissue under the bark of trees. They will feast on willow, river birch, maple, cottonwood, sweet gum, black cherry, tulip poplar, dogwood, beech, and oak. Around ponds, they also eat aquatic plants such as water lilies, duckweed, and cattails. On land they will consume grasses, sedges, and clovers. During winter, they depend on woody species for survival. In the late summer and fall, they collect small trees and limbs and store them underwater near the entrance to their burrow or lodge.

Where do they take up residence? As their name might suggest, North American Beavers are found throughout much of North America except for the far northern regions of Canada and the arid deserts of the southern United States and Mexico. Beavers reside in ponds, lakes, rivers, marshes, streams, and adjacent wetland areas. Beavers construct lodges or burrows to live in; most beavers in Illinois live in burrows rather than lodges. They excavate burrows into the banks of waterways and enter the burrow through entrances under water. The resting areas and nest of the burrow are excavated above the water line. Where the water is deep enough and there are enough trees for building, beavers build a lodge constructed of small tree trunks, limbs, and sticks that are held together with mud.

When and where do they breed and nest? North American Beavers are generally monogamous and mate for life. Beavers begin breeding when they are three years old. Breeding occurs in late winter. The female has one litter of three to five kits each year. With gestation period of approximately 3.5 months, their young are generally born from April to June. The female cares for them alone for the first month or two. When they are born, they are fully furred, have open eyes, and can swim within 24 hours. After several days they are also able to dive out of the lodge with their parents to explore the surrounding area.

Where do they migrate? North American Beavers do not migrate, nor do they hibernate. They are residents year-round across most of the U.S and Canada.

What is their conservation status? There is no concern. North American Beavers are not on any watch list. Today they are common throughout the state of Illinois; protected as furbearers. a trapping license is needed before attempting to harvest a beaver.

Do they make any interesting sounds? Beavers call out to others with a low, groaning sound. They also “talk” with their tails. Beavers communicate danger to other beavers by slapping their tail on the surface of the water. The slap creates a loud, cannonball-like sound. This signals to other beavers of potential danger. It also scares away predators.

Interesting Facts About North American Beaver:

  • North American beavers are the largest rodents in North America and the second largest in the world (South America's capybaras being the heaviest).

  • One of the animal kingdom's most versatile members is a skilled engineer, a tireless lumberjack, and an excellent swimmer.

  • The shape of the tail is an individual and family trait, varying from short and broad to long and narrow. It is practically hairless and covered with black scales.

  • The dams, canals and lodges beaver builds have gained them the reputation as “Nature’s Engineers”.

  • Secretions from glands in their tails are used in scent-marking and give the beaver its odd odor.

  • The average life span of the North American Beaver is approximately ten (10) years.

For more information on North American Beavers and sources of information used in this blog (these are several of the sources that I am using to learn as I blog), please visit Illinois DNRUniversity of Michigan Animal Diversity Web, Illinois Natural History Survey, Forest Preserve District of Will County’s “The Buzz”, and Nature Mapping Foundation.

The Carillon at Stonegate community is very fortunate to have a variety of wetland, forest and prairie environments conducive to a variety of birds and other wildlife. Our community and the Kane County Forest Preserve do an exceptional job in maintaining this natural environment – both for the benefit of the birds and wildlife and for our residents to enjoy.

 

Take a hike and see what you can find – and identify!