I was recently told by a lady that she had seen a road-killed beaver and was curious as to whether this was unusual. I told her that early spring is when a beaver colony breaks up, and the young beavers are on their own.

At this time, a beaver could get hit by a car.

Although an average beaver colony varies in size, the colony consists of a single-family unit. A beaver family consists of adults, the young from the first year and the young from the second year. Typically, beaver colonies number six individuals.

You very seldom see a colony grow larger because the oldest offspring, which are now the age of two, usually leave the lodge to start their own colonies. At this point, the young beavers are sexually mature and leave to find mates.

It has been said that the history of North America was written on a beaver pelt. This was due to the beaver being the motivating influence in the exploration and conquest of the North American Continent.

The beaver was thought to occupy all areas of North America, where food and water resources were suitable for winter survival. Prior to the European settlement, it was estimated that North America had up to 400 million beavers. However, by the 1800s, the beaver population across the North American range was nearly extinct.

The first economic interest in the beaver by Europeans and Asians was based on its medicinal importance. The fur was always highly valued, but the insatiable demand for castoreum sparked increased beaver taking.

By the 1600s, the top hat, which was made of felt produced from wool or fur, became a symbol of distinction in the royal courts of Europe. The finest felt was made of beaver fur. In 1638, King Charles I of England was rumored to have said, “Nothing but beaver stuff or beaver wool shall be used in the making of hats.” The species suffered near extinction to supply beaver skins and castoreum.

The word beaver comes from the old English word befor. To some Indian tribes in Canada, the word beaver means little people.

The beaver is the largest rodent in North America, with adults averaging 30-65 pounds; however, several beavers weighing more than 70 pounds have been taken in Pennsylvania.

Compared to the larger rear half of its body, the beaver has a disproportionately smaller head and front shoulders. A beaver’s skull is built strongly and compactly to support its powerful muscles and teeth. The incisor teeth are colored orange and grow continuously throughout their life.

The hard enameled front surface, of the incisors, functions as the sharp edge used to cut trees and peel bark. The rear side of the incisors is softer and wears more easily, creating a beveled, chisel-like edge.

Beavers are semi-aquatic and possess physical features that allow being adapted to a water environment and to dark, humid enclosed spaces of their burrows and houses. A beaver appears to be hump-backed and clumsy when walking on land; however, in water, a beaver is sleek and torpedo-shaped. A beaver propels itself with large, powerful hind webbed feet. The second inside toe on each foot has a moveable split nail that is used for grooming.

Although the front feet are not webbed, they are dexterous, heavily clawed, and well-suited for digging. The beaver’s flattened scale-covered tail aids in maneuverability while swimming. The tail is also used for balancing on land; signaling danger; storing fat for the winter and exchanging heat.

A beaver’s eyes, nose and mouth close when diving underwater. Transparent eyelids (nictitating membranes) protect a beaver’s eyes while swimming under water and from abrasive particles in the water. With the eyes located near the top of the skull and midway between the nose and skull base, a beaver can see above the water while swimming. The beaver also has a keen sense of smell and acute hearing for detecting food and danger.

A beaver has fur-lined lips that close behind the incisors, allowing the rodent to cut and carry sticks underwater. Two specialized structures enable a beaver to open its mouth while either gnawing underwater or carrying branches without danger of taking water into the lungs.

Another structural specialization is the elevated rear portion of the beaver’s tongue that fits tightly against the palate. The tongue blocks the passage to the pharynx except when swallowing.

A beaver can remain submerged under water for as long as 15 minutes. If held underwater a beaver will not drown from water inhalation into its lungs as with most mammals. Although carbon-dioxide narcosis gradually occurs, water never enters the lungs.

During my career as a PGC Wildlife Officer, I’ve live trapped and transferred many beavers. Within only a short time working as a wildlife officer, I admired the beavers’ work habits and their skills as builders.

Bill Bower is a retired Pennsylvania Game Commission Wildlife Officer. Read his blog and listen to his podcasts on the outdoors at www.onemaningreen.com.