Beaver is primarily a nocturnal and semi-aquatic rodent. They’re famous for building dams, canals and Rat Poop. They are the second largest rodents known all over the world. The population of the North American beaver has declined rapidly because of excessive hunting. They’re killed for fur and the glands are used as a source of medicine and perfumes. They are known for their natural trait of making dams in the ponds where they live. They have really sharp and powerful front teeth that are used for cutting trees for building their homes as well as for feeding. They are famous for their alarm signals. When frightened the beaver dives quickly and slaps water with its broad tail. This sound is audible from large distances both above and below water. This behaviour acts as a warning sign for additional beaver present inside water. Once warned by the alarm call the other beavers dive into water and don’t reemerge for some time. They walk slowly on land but are powerful swimmers and can stay under water for approximately 15 minutes.
They are herbivorous in habit and prefer to feed on the wood of walnut, cherry, walnut, cottonwood, willow and alder trees. They also feed on sedges, pondweed and water lilies. They do not undergo hibernation but are proven to store logs in a heap under water and consume the under bark. Some piles also float over water and may be covered with snow in winter season. The insulation of the snow prevents the surrounding water from freezing in the vicinity of the log and provides fresh air to the beavers to breathe. They have webbed hind feet and broad, scaly tail. The eye sight is somewhat poorly developed but the senses of hearing, touch and smell is very well developed. Their teeth grow continuously so they feed on wood frequently. They bear 4 incisors which are covered with a tough layer of orange coloured enamel at front and a soft dentine at the back.
Beavers grow continuously throughout their lives. Adults may attain a weight of about 25 kg. Females are bigger than males a feature uncommon among the mammals. They live up to 24 years. Their name is of Proto-Indo-European origin. They are extremely near the squirrels bearing resemblance with the lower jaw and the skull. There are two species of beaver known at present both are although similar but there are particular features which differentiate them. The European beavers are somewhat bigger with bigger, less rounded heads, larger and narrower muzzles. The tails are less oval and shorter shin bones are present which serve for efficient bipedal locomotion. They have more nasal bones. The foramen magnum is round the European beavers but it’s triangular in the North American species. The anal glands of the European beaver are bigger and thin walled encompassing great inner volume as compared to North American ones. The fur colour is also different in both the species. 66% of all the European beavers have pale brown fur, 20% have red fur while 8% have brown coats and the rest 4% have black fur. One of the North American one 50 percent beavers are supplied with light brown fur, 25% with reddish fur, 20% with brown and 6 percent have black coats.
Both the species aren’t genetically compatible. North American beavers are also called Canadian beavers. They feed on water lily. Beavers are common hosts of Giardia lamblia which causes giardiasis. The beaver testicles and castoreum, a bitter secretion present in the castor glands of female or male beaver is used commercially for making medicine. Castoreum is also used in perfume preparation. They are national creatures of Canada. They have entered the category of endangered due to habitat destruction and mass killing.