Beavers have thick brown fur and a distinctive flattened, paddle-like tail that can be 9-10 inches long and 6 inches wide. (Ryan Somma/Flickr)
The beaver is a large, brown, semi-aquatic mammal with a distinctive flattened, paddle-like tail. It lives in lakes, streams and forested wetlands throughout the Chesapeake Bay watershed.
Thick, glossy brown fur
Large, scaly, flattened, paddle-like tail that can be 9-10 inches long and 6 inches wide
Large, chestnut brown front teeth
Rounded head and small, rounded ears
Head and body grow to 25-30 inches long
Usually weighs 30-60 pounds
Lives in forested wetlands and tree-lined streams, rivers, ponds and lakes
Semi-aquatic, meaning it spends time both on land and in the water
Builds lodges of sticks and mud on islands, river banks and shorelines. Within their lodges, beavers live in colonies that include an adult male and female and their young.
Some beavers live in burrows within river banks
To protect their lodges, beavers build dams across streams to flood the area and create deep, quiet ponds. These ponds also allow beavers to safely transport food and logs through the water.
Primarily nocturnal, but occasionally active in late afternoon
Found throughout the entire Chesapeake Bay watershed
Eats mostly tree bark and leaves
Red maples, willows, alders, shadbush and redosier dogwoods are some of its favorite foods
Has a specialized digestive tract that allows it to digest tree bark
Also eats bay grasses such as pondweeds and the roots and rhizomes of aquatic plants such as lilies and sedges
Stores branches and stems in its lodge to eat during winter
Adults have few predators
Owls, hawks and otters may prey upon young
Humans hunt beavers for their fur
Reproduction and Life Cycle:
Each colony has only one breeding female
Adult pairs are monogamous, keeping the same mate for life
Adults begin breeding between 2-3 years old
Beavers have one litter per year
Adults mate in January and February
After four months, an average of 2-4 young (called kits) are born. At birth they are covered in thick fur, weigh about one pound and have open eyes.
Kits can swim within a week of birth and are weaned within 2-3 months
When they are two years old, yearlings (young born the previous spring) are driven out or leave their lodge
Can live 11 years in the wild
The largest rodent in North America
Teeth continue to grow throughout their lives
Regularly cuts down trees to eat and to repair dams and lodges. A beaver can chew down a small tree in just a few minutes.
Ponds formed by beaver dams are important habitat for fish and waterfowl
Their webbed feet and rudder-like tail allow beavers to swim about six miles per hour
Large tail makes a loud sound when a beaver dives underwater
Able to close its mouth behind its front teeth so it can carry logs and sticks underwater
Can be confused with muskrats and nutria. Beavers are the largest of the three animals and have distinctive flattened paddle-like tails.
Once treasured for its fur, which was used as a wind- and rain-proof fabric for stylish hats. This caused beaver populations to become depleted until just a few pockets remained. In the early 1900s, hunting and logging regulations were put in place to help beavers recover.
Sources and Additional Information:
Chesapeake Bay: Nature of the Estuary, A Field Guide by Christopher P. White