Beaver Castor canadensis
10 Interesting Facts About Beavers
>> Beavers form monogamous pairs and usually live in family groups of up to 8 related individuals called colonies. The younger siblings stay with their parents for up to 2 years, helping with infant care, food collection, and dam building.
>> Beaver families are territorial and defend against other families. In order to warn family members of danger, beavers slap their tails against the water, creating a powerful noise.
>> Beavers are primarily crepuscular and are only occasionally seen during the day.
>> The tails are one of the defining characteristics of beavers. They are broad and flat with large, blackish scales.
>> Another characteristic of beavers is their teeth. Like all rodents, beavers have large central incisors (front teeth) that are always growing. They must keep them trimmed by gnawing bark or grinding them against each other..
>> Beavers travel good distances from their homes to find food. If they find a good source, they build canals to the food source as a way to float the food back to their lodges. Logs and twigs are stored underwater for winter feeding.
>> Beavers float small trees and branches through canals to the stream where they are building their lodge.
>> The lodge can have several underwater entrances to keep out predators, with a large dry room inside for sleeping and raising young.
>> The living area is well insulated by the lodge and surrounding water so the temperature is considerably warmer inside the lodges than outside.
>> Beavers are beneficial to the environment. They are instrumental in creating habitats for many other animals, which is why they are called a “keystone species.”
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IDENTIFYING CHARACTERISTICS:
Beavers are thickset and heavy, about 4 ft (1.2 m) long, including a 1 ft (30 cm) paddle-shaped tail. They weigh as much as 50 lb (22 kg) in the southern part of their range and can reach 75 lb (34 kg) in the northern portion. Their legs are short and their hind feet large and webbed. They use their forepaws like hands. A pair of anal musk glands, or castors, produce castoreum, which is used by the beavers to waterproof their fur. Dense brown to tan underfur is covered by coarse guard hairs. Chisel-like front teeth enable the beaver to gnaw down trees used for building dams, island lodges, and canals.
RANGE:
Beavers are found throughout North America, with the exceptions of the Alaskan tundra, some areas of the Midwest, and the Florida peninsula.
HABITAT:
Beavers build dams to slow down the flow of water in streams and rivers and then build stable lodges for shelter in the ponds created. The dams are engineered according to the speed of the water; in slow water the dam is built straight, but in fast water the dam is built with a curve in it. This provides stability so that the dam will not be washed away. The lodges are made of sticks, mud and rocks. In faster rivers and streams, beavers sometimes build lodges into the sides of banks. Some lodges are large enough to fit a human inside them.
Reproduction:
In the southeast, beavers mate in the winter with two to four kits born in early spring. The kits are born fully-furred, with their eyes open and their incisor teeth erupted. The young usually stay with their parents for 2 years and then leave to make their own homes. Beavers only have one litter each year. The young reach maturity in 2-3 years.
FEEDING HABITS:
Beavers eat bark and cambium (the softer growing tissue under the bark of trees). Their favorites include willow, maple, poplar, beech, birch, alder, and aspen trees. They also eat water vegetation as well as buds and roots. Cellulose, which usually cannot be digested by mammals, is a major component of their diet. Beavers have microorganisms in their cecum (a sac between the large and small intestine) to digest this material.
CONSERVATION:
The conservation status differs with respect to source but there have been significant threats to the survival of the beaver. Beavers have been hunted and trapped extensively in the past and by about 1900, the animals were almost gone in many of their original habitats. Pollution and habitat loss have also affected the survival of the beaver. In the last century, however, beavers have been successfully reintroduced to many of their former habitats.