BEAVERS:

SCIENTIFIC NAME:

Castor Canadensis

PHYSICAL DESCRIPTION:

Beavers are the largest North American rodents. They usually weigh 60 to 70 pounds, but they can weigh as little as 30 pounds, and as much as 100 pounds!

Female beavers are usually larger than males. They both have one lower body opening called the cloaca, which serves to cover the reproductive organs. This is also the extraction hole for urine and feces. All beavers have glands under their skin called castors. These large glands produce oil that helps to waterproof their coats.

Beavers spend most of their time in the water so they are well equipped for aquatic life. Both male and female beavers have leathery, thick tails that they use like a rudder when they swim. Beavers' eyelids are clear so that when they swim, they can protect their eyes while seeing clearly in the pond, or river where they live. When beneath the water, beavers' ears and nose close up so that water does not enter. Their back feet are webbed and strong to propel them through the water. Beavers also have excellent hearing.

REPRODUCTION:

Beavers mate for life. They breed in the winter and they usually give birth to 3-5 kits after 5 or 6 months. The older the female beaver is, the more kits she has.

When the kits are born, they already have their self-sharpening teeth, and thick fur coat. They are able to swim right away and are fully equipped with their clear eyelids and protective oil glands.

Beavers live in colonies consisting of the adult couple, the kits, and the yearlings, offspring from the previous year. Beavers are highly protective of their colonies and become very aggressive towards alien beavers.

EATING AND LIVING HABITS:

For wild animals, beavers make very exquisite homes! Beavers are very protective of their homes and spend most of their time improving on them. To build their complex lodges, beavers first pile sticks into a large mound above the water. They chew through the mound from the bottom, to make a tunnel for an entryway.

The actual living quarters are chewed out of the middle to make a den. To protect the outside of the home, beavers seal the mound with mud and rocks, making sure to leave a hole at the top to let air circulate.

The special oil they use to waterproof their coats is the same oil used to mark their territories. This oil often leaves a red stain on the edge of the river or pond. Humans can detect these castor mounds easily because they emit a very pungent odor from the oil.

Beavers are vegetarians. They love to munch on aspen, willow, dogwood, birch, and maple twigs and bark. When it is spring they are spotted eating fruits, leaves, and buds of trees and bushes. When seen eating large pieces of wood that are not these specific kinds, it is a sign that the beavers' food supply is running low. When food is limited, beavers will travel long distances to gather more satisfying meals. They never relocate to a new home unless they do not have an adequate food supply.

BEAVER DAMAGE:

These cute and fuzzy creatures are not as innocent as they look! Beavers can create a lot of problems for their human neighbors. Beavers can flood roads, timber stands, farms, and many other important areas. Beavers build their dams larger in the winter to ensure the water is deep enough not to freeze. To help control water levels altered by dams, beaver pipes can be installed to channel water more efficiently.

THANKS TO BEAVERS...

Historically, beavers have been intrinsically tied to the economy, and to many Native American religions. Beavers have been hunted throughout the ages for their meat and their fur coats.  Their dams serve as important assets to rivers and other bodies of water. The dams help provide essential habitats of many other species to fish and rodents such as blue herons, otters, and to muskrats. When the dam eventually breaks down, the land and soil that flooded become richer and more fertile.

CREDIT:

www.animal-b-gone.com

www.wildlife.state.nh.us

Written by Sara Galles, Special Assistant to the Branch Coordinator, ABC Humane Wildlife

OTHER REFERENCES INCLUDE:

Ellen J. Snyder, Wildlife Specialist, UNH Cooperative Extension.
Desktop publishing provided by UNHCE Educational Marketing and Information Office.

Donald F. Hoffmeister, Mammals of Illinois, University of Illinois Press, 1989 by the Board of Trustees of the University of Illinois.