By: Marlene Affeld
Have you ever seen a 100 pound wet rat? The first time I spotted a large male beaver on Cedar Creek, (Mineral County, Montana) that’s exactly what I thought it was. I looked again, perhaps the gangly creature waddling down the bank was a bear cub. My next thought was, where is Mama Bear?
Meeting the beaver was a unique and rather unsettling experience. Movies and cartoons have often portrayed beavers as industrious, cheeky and tenacious. Beavers are all of that, however; in the wild they are also just plain ugly.
Beaver (Castor canadensis), semi-aquatic mammals, are the largest rodents in North America, north of Panama and they are the second largest rodent in the entire world (after the capybara). They are closely related to rats, squirrels and marmots. Beavers have an average lifespan of 12-15 years, however; beavers over 20 years old are not uncommon. Mature beavers normally weigh from 40 to 60 pounds, however many will reach a weight of close to 100 lbs.
In the water they are amazingly swift and graceful, slapping the water surface in frivolous play. Diving and cavorting, beavers use muscled, webbed rear feet to swiftly propel their torpedo-shaped bodies through the water. Their broad, dorsally flattened tail provides extreme mobility and maneuverability. Out of water the beaver is a clumsy, rather slow hump-backed creature.
A typical beaver family unit consists of a pair of adults, the yearlings and kits. Beavers will have 4-6 kits after a 105-107 day gestation period. Beavers breed from January through March. At about two years old, young beavers will either leave of their own accord or are driven from the parental home colony to seek new winter quarters.
Beavers once lived in most forested areas of the North American Continent. If one could find a stream, lake or river, one could most always find a beaver colony. Excessive fur trapping in the late 1800’s and early 1900’s nearly eradicated the beaver in Montana. Today, most colonies are found in remote regions where their activities do not interact with man.
“Nature’s engineers”, beavers have the ability to build dams and to modify the landscape to increase its suitability for their habitation. Beavers often build huge conical lodges at the edge of a lake or pond or will sometimes burrow into the bank of larger rivers. Beaver dam-building activities are integral components of the ecosystem as they play an important part in natural water flow and erosion control. Beaver ponds also provide recreational opportunities such as hunting and fishing.
In Montana, beaver problems can occur wherever there are trees, water and man. Most conflicts with beaver occur in areas where beaver cause problems by flooding pasture land, roadways or restrict water flow of streams. Sometimes beaver are really an annoying pest when they girdle ornamental or landscape trees or undermine property with their burrowing.
Since I viewed my first beaver on Cedar Creek, the US Forest Service has trapped the Cedar Creek Colony for relocation and demolished the dam. Unfortunately, their dam construction was causing flooding upstream and washing out the roadbed.
Intelligent creatures, beavers construct stick and mud dams in order to build their lodges in the resulting ponds. The lodge provides protection from marauding bears, wolves, coyotes and cougars. Working primarily at night, these nocturnal creatures are hardworking, prolific builders, carrying stones and mud with their powerful fore-paws and twigs and branches between their teeth. The beaver’s chisel sharp and rock strong incisors grow continuously. These guys are really industrious! The largest beaver dam on record was discovered near Three Forks, Montana. Visible by satellite, it is 2,140 feet long, 14 feet high and 23 feet thick at the base. Amazing!
Beaver ponds play a significant role in the formation of Montana’s plant and animal habitat. Beaver dams create ponds that help stabilize water tables and help reduce rapid rain runoff. Beaver dams reduce soil erosion and improve soil quality, with runoff deposits settling into quiet pools near their dams. Beaver habitat is rich in plant, aquatic and animal life, making beaver ponds an excellent locale for observing nature.
Hindered by very poor eyesight, beavers compensate by having highly developed senses of smell and touch as well as exceptional hearing. When startled or frightened, beavers will use their flat and scaly broad tails to loudly slap the water as a signal of danger. In response to the alarm, which can be heard over a considerable distance both above and below the water, the beaver colony will “dive for cover” and may not re-emerge until some invisible sense gives them an “all clear”. The Salish Indian Tribe that lives in Northwest Montana has a tribal legend that says beavers are fallen Indians, doomed to the lowly state of a beaver by the Great Spirit.
Strict herbivores, beavers will feast on a wide variety of herbaceous and woody plants. They enjoy wild berries in season and especially crave the water lilies found in many alpine ponds and lakes. Cottonwood, willow, aspen and alder are important foods, much of which is stored in caches for winter consumption. Beaver will also gnaw and harvest birch and maple trees.
A staple of Native Americans and early settlers, beaver meat is fine-grained, deep red, moist and tender. When properly prepared, beaver meat is similar in flavor to roast pork. The high fat content of the succulent tail meat is especially savored.
Prized by hunters and trappers for its sleek, warm pelage, the beaver’s value as a fur animal lead to the early exploration of the North America Continent. Rich chocolate brown in color with black to reddish guard hairs, beaver pelts are soft, extremely dense and have excellent insulating qualities. At one time considered the most valuable of furs, beaver was also trapped for its castor glands which produce castoreum, a highly sought product used in making perfume. In Montana the beaver is an official furbearer and is managed and protected by regulated fur harvests.