American
Beaver Castor
canadensis [kas' tor kan uh den' sis]
Description
The beaver is the second largest rodent,
exceeded in size only by the capybara. It is up to 3½ feet long, including 1
foot of broad scaly tail, and may weigh between
30 and 75 pounds. Its muzzle is blunt, ears
small, and it has five toes on each foot. The
toes on the front feet are strongly clawed and
used for digging, manipulating food and carrying.
The hind feet are webbed, with two split claws
for grooming the fur and spreading waterproofing
oil.
Distribution and
Habitat
The American beaver ranges
throughout all of North America except for the
northern regions of Canada and the deserts of the
southern United States and Mexico.
Habits
Beavers live in loose colonies,
each made up of a set of parents and their
offspring. Their home may be in a burrow in a
bank, with an underwater entrance, or in a lodge
in a "beaver pond," a pool made by
damming a stream or river until it overflows. The
lodge is built of sticks and mud, often against a
clump of young trees, with underwater entrances,
a central chamber which is above water level, and
a ventilating chimney connecting the chamber with
the top of the lodge. The central chamber may
measure 8 feet wide and up to 3 feet high.
Beaver families are territorial
and defend against other families.
Beavers are primarily
nocturnal.
Diet
Beavers eat bark, mainly of
aspen, maple, poplar, beech, birch, alder and
willow, from the smaller branches cut when
building the dam and lodge. They also eat water
vegetation, as well as buds and roots. Twigs and
branches are stored around the base of the lodge,
the bulk of which are eaten by youngsters during
the winter. Beavers may 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.
Reproduction
Beavers pair for life. Mating
takes place in January or February. Two to eight
kits are born after a gestation period of 65 to
128 days. At birth each weighs about 1 pound and
is about 15 inches long, including 3½ inches of
tail. They can eat solid food at one month, but
are not fully weaned until 6 weeks of age. Young
remain with their parents for 2 years, becoming
sexually mature at 2-3 years. A beaver may live
up to 20 years in the wild.
Scientific
Classification
phylum Chordata
subphylum Vertebrata
class Mammalia
order Rodentia
suborder Sciurognathi
family Castoridae
genus & species Castor canadensis
Animal Diversity Web http://animaldiversity.org/accounts/Castor_canadensis/
Capybara
Questions or comments about
this page?
|