BEAVER DAM COULD TEST YOUR ENVIRONMENTAL CONSCIENCE
walk in the woods near a stream has given me the opportunity to witness
one of natures marvels that I have never seen before the
building of a beaver dam.
first evidence of something unusual happening came in autumn after a
month of no rain when I measured the water level. I do this at least
once a week downstream from our cabin and was surprised to find that
instead of dropping an inch or so, it had actually risen 2 inches. I
attributed it to mismeasurement until I took my walk.
are unquestionably keystone species in a region with small to moderate-size
streams. They not only modify the habitat but can also change the environment
in ways that dramatically influence the lives of animals, including
people, and plants.
activity can result in big trees dying from flooding and smaller ones
being debarked for food or cut down for dam construction. A mile downstream
from my incipient beaver dam a larger one has flooded several acres,
leaving tall, lifeless sweetgum and pine trees that began life in a
terrestrial habitat and cannot persist in an aquatic one.
are affected, too. Large aquatic salamanders called sirens thrive and
become more abundant in pools of a stream created by beaver dams. We
once observed more than 500 sirens along the margins of a small stream
when a dam was removed and the water level dropped.
watersnakes and turtles are more apparent, and maybe even more abundant,
around beaver dams, which create areas for basking on sunny days. Waterfowl,
such as wood ducks, are attracted to the pond created above the dam.
Clearly, beavers and their dams set the tone of the neighborhood for
many wildlife species.
about beavers speak to the impressiveness of these gigantic rodents.
The historical geographic range for beavers is vast, extending from
northern Florida and Mexico to Alaska and Newfoundland. Adult beavers
can weigh more than 80 pounds, and their North American ancestors were
even bigger, reaching the size of a full-grown black bear.
live 35 to 50 years in zoos and more than 20 years in the wild. The
longest beaver dams, reported from Montana and from Alberta, Canada,
are more than 2,000 feet long. Surely beavers across the continent are
working feverishly to break the record. Beavers are usually nocturnal,
but I saw one on top or our beaver dam during the day. Perhaps an OSHA
dam safety inspector.
the conundrums with beavers is that their positive traits being
chubby, cute, industrious pioneers arent always enough
to outweigh less desirable traits. I know folks who have had beavers
cut down a beautiful dogwood tree, flood an area intended for a garden
not a fish pond and dismantle a wooden boathouse to build the beaver
lodge. The predicament is how to keep beavers for outdoor show-and-tell
yet not have them misbehave, from a humans point of view.
society will always face perplexing wildlife problems and environmental
dilemmas. Entertaining, yet potentially destructive, beavers are a good
example of the complexity inherent in environmental preservation, with
no simple solution as to how to handle the issue. A range of responses
are available for dealing with nuisance wildlife. Which solution people
choose will depend in part on their environmental conscience.
that too much of this beaver-dam building might cause on our stream
is to make it more difficult to navigate up and down in a canoe or john
boat. But carrying a small boat around the end of a beaver dam to get
to the other side of the stream will not be much of an imposition in
return for getting to experience a natural phenomenon that can change
the character of the habitat and its wildlife. That is, as long as I
dont see part of our cabin being used to build that dam.
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