World's biggest beaver dam discovered in northern Canada

May 06, 2010 by Michel Comte and Jacques Lemieux
This 2008 handout photo courtesy of the Wood Buffalo National Park in Northern Alberta shows the world's biggest beaver dam. A Canadian ecologist has discovered the world's biggest beaver dam in a remote area of northern Alberta, using satellite imagery and Google Earth, it was announced.

A Canadian ecologist has discovered the world's largest beaver dam in a remote area of northern Alberta, an animal-made structure so large it is visible from space.

Researcher Jean Thie said Wednesday he used satellite imagery and Earth software to locate the dam, which is about 850 metres (2,800 feet) long on the southern edge of Wood Buffalo National Park.

Average beaver dams in Canada are 10 to 100 metres long, and only rarely do they reach 500 metres.

First discovered in October 2007, the gigantic dam is located in a virtually inaccessible part of the park south of Lac Claire, about 190 kilometres (120 miles) northeast of Fort McMurray.

Construction of the dam likely started in the mid-1970s, said Thie, who made his discovery quite by accident while tracking melting in Canada's far north.

"Several generations of beavers worked on it and it's still growing," he told AFP in Ottawa.

Mike Keizer, spokesman for the park, said rangers flew over the heavily forested marshlands last year to try to "have a look." They found significant vegetation growing on the dam itself, suggesting it's very old, he said.

"A new dam would have a lot of fresh sticks," Keizer explained. "This one has grasses growing on it and it's very green."

Part of the dam may have been created by naturally felled trees, and the beavers "opportunistically filled in the gaps."

Thie said he recently identified two smaller dams sprouting at either side of the main dam. In 10 years, all three structures could merge into a mega-dam measuring just short of a kilometer in length, he said.

This undated satellite image made available by Google Maps shows a beaver dam, more than eight football fields long, situated in northern Alberta's Wood Buffalo National Park which straddles the Alberta-Northwest Territories border. Ecologist Jean Thie said Friday, May 7, 2010, that he found the dam using Google Earth and NASA technology in 2007 while researching the rate of melting permafrost in the country's wetlands. (AP Photo/Google Maps)

The region is flat, so the beavers would have had to build a massive structure to stem wetland water flows, Thie said, noting that the dam was visible in NASA satellite imagery from the 1990s.

"It's a unique phenomenon," he said. "Beaver dams are among the few animal-made structures visible from space."

North American beavers build dams to create deep, still pools of water to protect against predators, and to float food and building materials.

A 652-meter structure in Three Forks in the US state of Montana previously held the record for world's largest beaver dam.

Thie said he also found evidence that beavers were repopulating old habitats after being hunted extensively for pelts in past centuries.

"They're invading their old territories in a remarkable way in Canada," he said. "I found huge dams throughout , and beaver colonies with up to 100 of them in a square kilometer."

"They're re-engineering the landscape," he said.

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User comments : 17

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mikehevans
May 06, 2010
This comment has been removed by a moderator.
Lambduh
May 06, 2010
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THoKling
3.5 / 5 (2) May 06, 2010
I'm wondering what incentive the beavers have to make it so large. Is it because the land is too flat otherwise?
El_Nose
5 / 5 (1) May 06, 2010
i think beaver just make dams and this just happened to be a good spot. It would be funny though if two different bveaver groups started making the dam at opposite sides and luckily met in the middle.
RobertKLR
May 06, 2010
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abhishekbt
not rated yet May 06, 2010
Beaver dams are among the few animal-made structures visible from space.


I thought the wall of china was the ONLY man made structure visible from space. What other animal made things is the author talking about?
po6ert
5 / 5 (1) May 06, 2010
the beaver are signaling to extraterestial kin about landing site availible in arizona
abhishekbt
not rated yet May 06, 2010
Actually speaking, beavers are competing with us!

Who said only humans can build a structure visible from space?
OlenGregoryIW
not rated yet May 07, 2010
Thie said he recently identified two smaller dams sprouting at either side of the main dam. In 10 years, all three structures could merge into a mega-dam measuring just short of a kilometer in length, he said.

The region is flat, so the beavers would have had to build a massive structure to stem wetland water flows, Thie said, noting that the dam was visible in NASA satellite imagery from the 1990s.Instant Payday Loan Lenders
LifeatDrToms
not rated yet May 07, 2010
Normally, one family of beavers build a dam in their territory. It is not clear to me whether more than one family was involved with this huge dam. Is communal building occurring?
talanock
5 / 5 (1) May 07, 2010
Beaver dams are among the few animal-made structures visible from space.


I thought the wall of china was the ONLY man made structure visible from space. What other animal made things is the author talking about?


Actually, the Wall of China isn't visible from space. No man made object is.
TheWadd
5 / 5 (1) May 07, 2010
Did the beavers file an environmental impact study before they started construction?
Feldagast
5 / 5 (1) May 07, 2010
I doubt this is visible from space, without optical enhancement, same as the great wall of china.
yyz
not rated yet May 07, 2010
"I thought the wall of china was the ONLY man made structure visible from space. What other animal made things is the author talking about?"

Oil spills in Earth's oceans.
Djincs
not rated yet May 08, 2010
the great coral rif is visible too

bbd
not rated yet May 08, 2010
Eventually the beaver will build a dam so big it will destroy us all!
CaptBarbados
not rated yet May 09, 2010
I'm wondering what incentive the beavers have to make it so large. Is it because the land is too flat otherwise?


They develop larger and larger family groups which have maintain larger networks of small canals to get to their preferred foodstock. Eventually, these areas form natural lakes that represent "islands of water" in rather arid, frozen regions.
El_Nose
5 / 5 (1) May 10, 2010
I for one welcome our future beaver masters.
Roofi
not rated yet May 11, 2010
I'm new to thiswebsite which is a great experience for me.love physorg
braindead
5 / 5 (1) May 12, 2010
I can see my pool chair at the back of my house on Google. So that's at least one man made thing big enough to 'see from space'. It's a meaningless term. Seen by what? by naked eye? by short-sited person in low Earth orbit who's left his specs at home? In space craft half way to Mars? Using the Hubble pointed Earthwards? Be good if a science based web site used more precise terms like the unit "football fields" for instance.