Streamside Companions - The Beaver
By Neil M. Travis, Montana
No other animal had a greater influence on the exploration
of the American West than did the beaver. Trappers, led by
the French, began to penetrate the interior of the current
states of Montana, Idaho and Wyoming in the latter part of
the 1700s. In 1804 Lewis and Clark commenced their famous
trip to explore the Louisiana Purchase. When they returned
they brought news of extensive numbers of beavers in the
land they had just explored. By the early 1830s, barely
25 years after the conclusion of the Lewis and Clarks
expedition, the beaver had been trapped out of many areas.
In 1834 the American Fur Company, owned by John Jacob Astor,
sold out his Western trapping operations due to a scarcity
of beaver, and a declining demand for their fur. The fabulous
days of the beaver fur trade were over.
Besides its impact on the exploration of the American West,
the beaver had a tremendous impact on the overall look of
the areas in which it lived. Except for man, no other
mammal has the ability to radically change the landscape.
Many of the western rivers originated in the high mountains,
and plunged headlong towards the sea, carrying with them
minerals and soil particles. Beavers moved into the high
mountain valleys and constructed dams. This dam building
activity accomplished two things: it created a pond where
the minerals and soil particles settled out, and it opened
up the forest, creating an open valley. Both of these
activities would prove to be of great benefit to the
first permanent settlers who followed the Mountain Men.
Beavers belong to the rodent family and may reach a
weight of over 60 pounds. They are covered with a dense,
deep brown coat. From the tip of the tail to the end of
their nose they are 3 to 4 1/2 feet long. They swim by
using their webbed hind feet and broad flat tail.
Beavers can set upright, using their tails for balance.
Their food consists of the bark and the outer layers
of aspens, alders, birches and willows. In addition,
various parts of many aquatic plants are consumed. In
cutting a tree they use their large upper teeth for
leverage, the cutting action is performed by the lower
teeth. Larger trees are peeled where they fall and
smaller sections are dragged to the water for use in
dam building or for food. Beavers will travel up to
200 yards from the water to obtain trees, however
they are reluctant to do so for long and will soon
abandon a location when the available trees are too
far from the water.
Beavers use the trees they cut for building dams,
food and lodging. In fast flowing streams, where
dam construction is impossible, beavers live
underground. They build a feed bed consisting of
unpeeled tree limbs and dig a burrow into the bank
for shelter. These beavers are sometimes referred
to as 'bank beavers.'
Under the proper conditions beavers can construct
very substantial dams. These large dams create very
impressive impoundments. Dams of over 2,000 feet in
length have been recorded, but most dams are less
than 100 feet in length. The impoundments they create
provide valuable habitat for various types of wildlife.
Ducks and geese utilize them for feeding and nesting.
Trout, especially brook trout, benefit from the
increased insect population that is associated with
the pond. Moose find them a ready source of food, and
other ungulates, like deer and elk are attracted to
the clearing that the they create.
For many years beavers were kept in check by natural
forces and by trapping. In our modern era the wearing
of fur is out of vogue, and in many areas beaver numbers
have soared. Unchecked, the beavers have become a nuisance,
cutting trees in suburban backyards, damning up irrigation
ditches and thwarting stream rehabilitation projects. In
parts of the Pacific Northwest beaver activity has blocked
salmon spawning streams, especially in the headwaters.
Abandoned beaver dams rapidly fill with silt, and quickly
become unsuitable for trout.
Anglers will rarely encounter beavers during the daylight
hours, since they are normally active only during the early
morning and evening hours. A startled beaver will slap its
tail vigorously on the surface of the water, creating a
sound as sharp as the retort of a rifle. In the calm
stillness of evening or early morning it can set the
heart to racing.
Beavers present no threat to anglers, and their activity
is are generally benign, however their dam building
activity is a challenge for fishery managers. Their
dams can quickly block spawning trout and make spawning
areas inaccessible and unusable. Tree removal may allow
excessive warming of the water impacting the ability of
a stream or pond to provide trout habitat. ~ Neil M. Travis, Montana/Arizona
From A Journal Archives
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