Animals returning to waterways may mean cleaner water for
people, too. After being trapped to near extinction for their pelts from the
1700s to early 1900s, the beaver is finally beginning to make a comeback in Detroit, Michigan.
Why now?
Wildlife officials say cleaner waterways may play a part. Similarly, beavers are being reintroduced
into Scotland. Before examining why, first let's learn more about what and why
beavers build.
Semi-Aquatic Rodents
While "semi-aquatic rodents" is a mouthful of a way to
explain a beaver, it is accurate when you think about it. The beaver is the world's second-largest
rodent, and is divided into two species – one is native to North America; the
other is native to Eurasia.
Well known for using their teeth to down trees for the
construction of protective dams and housing lodges, beavers also build canals
to float heavy building materials. Their
wide tail is a tell-tale beaver characteristic, which is used for slapping the
water when danger is near. Beavers come
in a variety of colors including pale brown, reddish brown, brown, and
black. About 66% of European beavers are
pale brown compared to 50% of American.
Contrary to popular belief, beavers do not hibernate during
the winter. The lodges that they live in are insulated and snow pile-up can
help the water from freezing in the immediate surrounding area.
American Recovery
A motion-sensing camera recently discovered a beaver living
in the Detroit River.
This is significant because according to U.S. Fish and Wildlife
Services, beavers have not been seen in the river for 75 to 100 years. Wildlife experts guess the beaver may have
swum from the Canadian side of Lake St. Clair.
Other wildlife that has returned to the area includes fish
like sturgeon and walleye, and birds like falcons and eagles. Cleaner waterways
are cited for the species' returns.
Similarly, cleanups of the Bronx River
in N.Y. have lead to a return to a pair of beavers there. Beavers were either hunted to near-extinction
(a beaver-pelt hat adorns the N.Y.-state seal) or evicted by farmers about 200
years ago. The N.Y. Times has a good video
about the story, complete with thermal images of the beavers inside their
lodge.
Scottish Recovery
Beavers are not only returning to their homes in the U.S. A project in Scotland will reintroduce four beaver
families into the wild – more than 400 years after they were hunted to
extinction. Funded by the European Union
(EU), the first step of the project was for nature experts from Scotland to study beavers in Norway.
The return of the beavers does not come without some
controversy. A spokesman from the
Confederation of Forestry Industries opposed the plan because of beavers' disruptive
tendencies in woodland settings. Local
landowners argued that the beavers would threaten farms, fisheries, and
woodlands.
Proponents to the plan argue that beavers create cleaner
waterways with less pollution. According
to John Gurnell, a wildlife biologist at Queen Mary College, beavers can alleviate the
effects of flooding and raise water levels during droughts in addition to
improving water qualities. His report
added that beaver ponds tend to be richer in wildlife than normal rivers.
Resources:
http://www.msnbc.msn.com/id/29222122/
http://en.wikipedia.org/wiki/Beaver
http://www.cbc.ca/technology/story/2009/02/16/beaver.html
http://video.nytimes.com/video/2007/02/26/science/1194817095374/the-beaver-s-return.html
http://www.physorg.com/news146486441.html
http://heritage.scotsman.com/beavers/Beavers-return-to-Scotland-comes.3293695.jp
http://www.dailymail.co.uk/news/article-1162750/Return-beaver-cut-water-bills-scientists-say.html
http://www.kdwp.state.ks.us/news/layout/set/print/Hunting/Furharvesting/Furbearer-Gallery/Beaver-Castor-canadensis
http://www.wildlife.state.nh.us/Wildlife/Wildlife_profiles/profile_beaver.htm
|