The Largest Beaver Dam In The World

In A Nutshell

Beavers are the engineers of the animal kingdom whose work is seemingly never done. Their dams and lodges can grow to enormous proportions, capable of transforming major tracts of land and creating entire ecosystems for fish, frogs, and other wildlife. Average-size beaver dams are impressive, but even they are dwarfed by the 850-meter-long (2,800 ft) dam discovered in Canada. The rodents started building the structure in the 1970s, and it has grown to become the world’s largest beaver dam.

The Whole Bushel

Humans are inarguably the creatures that enact the most physical changes to the planet through buildings and technologies, but other animals do their fair share of environmental manipulation as well. For instance, both ants and termites haul around soil and construct it into massive mounds, birds are capable of building nests that overtake entire trees, and moles can dig convoluted tunnels that span several kilometers. However, in terms of sheer size of the architecture, no animal can match the building skills of the beaver.

Beavers are natural lumberjacks that have built-in “saws” in the form of sharp incisor teeth and incredibly strong jaws. They use these teeth to fell trees for the purposes of eating and constructing both dams and lodges. They are so busy and strong that they can move over 10 times their body weight per day, which equates to roughly 225 kilograms (500 lb), and a single beaver chops down more than 200 trees per year. With so much wood at their disposal, they can easily expand their dams by meters per day and quickly change an area’s landscape.

Besides chopping trees, these large rodents incessantly move mud and gather rocks and stones, forever trying to dig their ponds deeper and make their homes larger. Considering their hyperactive nature and predilection for engineering, it’s easy to see how, if left to their own devises, these critters could construct something truly colossal. And they’ve done just that in Canada’s Wood Buffalo National Park.

The Wood Buffalo beavers have been constructing their dam in a remote section of the park since the 1970s and show no signs of slowing down. When last measured it was about 850 meters long and deemed the largest beaver dam in the world. In comparison, most beaver dams are only 10–100 meters (33–330 ft) in length. Amazingly, park staff had no clue the gigantic structure even existed until 2007 when a researcher discovered it on Google Earth while analyzing melting permafrost in Northern Canada. While it seems odd it would go unnoticed for so long, the park itself is huge (bigger than all of Switzerland), and the area where the beavers live is largely inaccessible to humans.

Currently the beavers are extending two smaller dams on either side of the main dam, and, if they keep at it, in less than a decade the three could join into a 1-kilometer-long super-dam. Prior to this discovery, a 652-meter (2,100 ft) barrier in Three Forks, Montana held the title as the world’s biggest beaver dam.

Other than a human, no other creature makes such significant changes to its environment as a beaver does. It’s this trait that made them highly revered among Native American tribes and earned them the nickname “little people.”

Show Me The Proof

Parks Canada: Wood Buffalo National Park (includes photo of the beaver dam)
Animal Planet: Fooled by Nature: Beaver Dams
Discovery: Largest Beaver Dam Seen From Space
BBC Nature: Beavers
Beaver Solutions: Beaver Biology