BUSY BEAVERS BUILD REALLY BIG DAM

By Debbie Bulloch



With all the recent news stories about disasters, including deadly earthquakes in Haiti and Chile, the huge Iceland ash flow and the man-made disaster in the BP oil platform in the Gulf of Mexico, it is nice to report a feel-good story about the more benign side of Mother Nature.

It seems that for the past 20 years or so, a large colony of very industrious and hard-working Canadian beavers has been busy at work building the world’s largest beaver dam. In fact, the dam is so large that it can be seen from Earth-bound satellite – making it the only non-human structure to earn that distinction.

For those of you not familiar with beavers, they are large, furry creatures with strong teeth and a compulsion for building dams. Beavers are the second-largest rodent in the world (after the capybara). Their colonies create one or more dams to provide still, deep water to protect against predators, and to float food and building material.



The North American beaver population was estimated to have once exceeded 90 million. As of 1988 (the date for which the latest estimates are available) the beaver population was estimated to range between 6–12 million. This population decline was due to extensive hunting for fur and because the beaver’s glands were used as medicine and perfume.

In Canada, where this colony of eager beavers resides (sorry I couldn’t resist) beavers have achieved great historical and cultural importance. The beaver has been designated as Canada’s national animal (ahead of the goose and the moose). The beaver is depicted on the Canadian five-cent piece and was on the first pictorial postage stamp issued in the Canadian colonies in 1849 (the so-called "Three-Penny Beaver"). As a national symbol, the beaver was chosen to be the mascot of the 1976 Summer Olympics held in Montreal with the name "Amik" (meaning "beaver" in Ojibwe). The beaver is also the symbol of many units and organizations within the Canadian Forces, such as on the cap badges of the Royal 22e Régiment and the Canadian Military Engineers. Toronto Police Services, London Police Service, Canadian Pacific Railway Police Service and Canadian Pacific Railway crest all bear the beaver on their crest or coat of arms.



What is remarkable about the dam-building beaver colony on the southern edge of Wood Buffalo National Park(Alberta, Canada) is not just the size of the damn, which is estimated to be about 850 meters (it is common for beaver dams in Canada to reach 500 meters in length). What is truly remarkable is that the dam is a cross-generational project. Given its size, scientists estimate that it took over 20 years to build the dam to its current size; this was a project started by one generation of beavers and enlarged upon by succeeding generations. The construction of the dam is remarkable because it illustrates a commonality of purpose and enterprise not previously observed in the animal kingdom.



The dam is remarkable for yet another reason. As previously noted, the North American beaver population was nearly decimated by trappers who hunted the beavers for their valuable pelt. With laws aimed at protecting them from unchecked hunting and trapping, these amazing natural engineers have made a strong come back from the brink of extinction.

Score one for Mother Nature!

To read more about the Wood Buffalo Park beavers go here:

Alberta's huge beaver dam sparks media buzz

Here:

Largest Beaver Dam

Here:

World's biggest beaver dam discovered in northern Canada