live in colonies in streams and lakes bordered with trees.
The Des Plaines River, winding through Ryerson Woods, is an
ideal home for the elusive animals. All along the river trails
you can see the results of the beavers' work. One beaver at
a time tries to fell a tree, gnawing wherever it is handy
and letting the tree fall in any direction. Other beavers
feed on the fallen leaves and buds or gnaw off branches to
build dams or lodges. In the fall, they will secure branches
underwater in the mud of the river bottom near their lodge
entrance. When winter comes, these stored branches provide
food until spring comes.
animals are active mostly at night from late afternoon to daybreak. They stay
in the water most of the time. If alarmed, they may slap the water with their
flat tail and dive under; nearby beavers will head for deep water.
beavers are 25" to 30" long not including a 9-12" broad flat tail
used for swimming underwater. They weigh 45-60 lbs. Their fur is mainly dark brown
with lighter brown fur underneath and black ears, feet and tail.
beaver lodge is a mound of large bark-stripped branches and logs covered with
finer branches and vegetation, and finally, plastered with mud. Usually the top
of the lodge is not plastered, to allow for ventilation. It may be located along
the shore and over a bank den, or surrounded by water. Each lodge has two tunnel
entrances excavated underwater through the mud up into the mound. As the beavers
add to the lodge year after year, it may become very large. Lodges are usually
4 by 20 feet, but some have been seen even 40 feet across.
beavers mate in the water. Both parents, and even some yearlings may remain in
the lodge during birth. The young kits are born fully furred and able to walk.
In only a couple of days, they will go into the water and by 10 days are able
to dive. In 1 to 2 months, they will leave the lodge with their parents. The young
beavers are fully grown at 2 1/2 years and in their 3rd spring or summer leave
home to stake out a home range, build a dam and lodge, and find a mate.
(photo courtesy of Forest
Preserve District of DuPage County)