Citizen scientists recruited as dam detectives to pinpoint beaver homes from satellite images

The Miistakis Institute and the Alberta Riparian Habitat Management Society are asking citizens to become dam detectives and find beaver homes from satellite images. 

Using Zooniverse, an online research platform, citizen scientists can help determine where beavers are present or absent on the landscape — which in turn will help guide the selection of restoration sites and improve the overall health of streams in southern Alberta. 

"We're kind of looking for those spots where beavers aren't currently building dams," said Miistakis Institute conservation analyst Holly Kinas.

"So maybe we can come in and kind of support them by restoring those stream sections and then beavers can move back in and take over that work for us."

The area, within the Kainai Nation, generally spreads west from Lethbridge, Alta., to the British Columbia border. It includes Waterton Lakes National Park and ends just north of the Canada-U.S. border in Montana. 

Kinas said they have already tried restoration techniques, in partnership with the Blood Tribe Land Management Department, installing what's called a beaver dam analog — mimicking the form and function of the real thing. 

Amy McLeod, who is a riparian specialist with the Alberta Riparian Habitat Management Society, calls beavers ecosystem engineers. The animals have helped shape North America's rivers and streams, she says.

When beavers build their dams they change the flow of water. In instances of flood, researchers have seen that dams delayed the peak of a flood event, buying time for those downstream. But their dams can also act as what McLeod calls speed bumps, slowing down water so it has a chance to stay on a landscape and seep into the ground — which helps with drought and water scarcity.

"I would say that beaver or beaver mimicry is, you know, one of I think, the most useful climate adaptation strategies for us, particularly in southern Alberta, where we're experiencing water scarcity," said McLeod. 

Kinas said they want to do more of this work, but finding the ideal spots for similar people-made dams is labour-intensive. So why not let beavers lead the way from space?

"The beauty of this project, too, is that to find these good sites, it would take a lot of time and effort to send someone out to go walk 7,000 kilometres of stream segments," Kinas said.

"So by being able to crowdsource … we can kind of achieve a goal that would be hard for us to achieve with traditional fieldwork."

In each satellite image, a 250-metre area, the user checks for beaver dams and lodges and reports back. Each image is inspected by at least eight users so that the data isn't just coming from a single source. Users record how many dams they see and whether or not they can spot water in the image. 

"We have over 30,000 images that need to be classified," Kinas said. 

This initiative, McLeod said, is part of a larger coexistence project called Working With Beavers.

The Miistakis Institute and the Alberta Riparian Habitat Management Society, also known as "Cows and Fish," have come together to work with municipalities, government agencies, and landowners on beaver coexistence. 

While beavers used to dominate the Canadian landscape, European settlers nearly wiped them out. And McLeod said experts still don't know how those populations have recovered since that time. 

Beavers a benefit or bother? 

The animals are still considered a pest by many.

And there is a reason behind that. Beavers can be destructive, whether they're chomping down treasured trees, or flooding farm pastures. 

"There's still definitely the traditional management approaches, which is, you know, trap the beavers, shoot the beavers, blow up their dams," McLeod said. "These are actually really expensive things to do and they're really dangerous for obvious reasons."

Instead, McLeod said they work with landowners to give alternatives, like pond levellers and other coexistence measures that could save money in the long run, and help improve the landscape. 

"Our mandate is really about empowering people and getting tools in the hands of people, needing people to see the natural solutions around them already," McLeod said.