Busy beavers help mitigate the effects of warming rivers.
Troublemakers or valuable contributors to the ecosystem? Your perspective of beavers, says David Gregory, senior wildlife biologist at the Georgia Department of Natural Resources, “depends on your interaction with them.”
“People who don’t have a negative interaction with them have a positive feeling about them … and think of them as a neat critter that’s associated with wetlands,” Gregory says. “People who have homes along streams or ponds and the beavers are chewing on their favorite tree or causing backup water to flood their property, then obviously they have a negative interaction and maybe a negative view. But even within that negative view, so many people understand that they do play an important ecological role.”
Increasingly, scientists are noting the beneficial impact of beavers in a warming world. A Stanford University study published in 2022 concluded that as the effects of climate change worsen, beaver dams may help lessen the damage, improve the water quality of rivers and assume an even more important role. Thanks to their industrious building habits, beavers remove unwanted nitrate, a form of nitrogen that promotes overgrowth of algae that starve water of needed oxygen, by engineering a significant difference between water levels above and below their dams.
Slowing the flow of natural waterways, the way dams do, also allows sediment to settle, thereby cleaning the water and getting rid of another problematic substance.
“One of the biggest pollutants in the United States is soil,” Gregory says. “It’s soil in our waterways that clogs them up and runs out a lot of the invertebrates that really need clean, flowing water. Whenever all those little gravelly spots are filled up with sediment, it doesn’t bode well for their survival.”
Backing up water also slows it enough to soak into the soil, improving the water table in the area.
“Groundwater is exceptionally important for all of us,” says Gregory. “The more water you put into the ground, the better. The most important thing to understand, in my opinion, is that beavers are a keystone species. They are a critical animal that has a large impact on their habitat and the surrounding habitat.”
Creatures living in or near freshwater venues, from fish, mussels and crawfish to muskrats, river otters and raccoons, even foraging birds and bats, benefit from the beavers’ busy habits.
“Many critters depend on their survival based on how beavers manipulate habitats, whether they’re creating tons of wetlands for animals, or modifying the types of vegetation around them to create more sun, which in turn provides opportunities for grasses to grow,” Gregory says.
Another plus: Beavers can build their homes just about anywhere, from large rivers to small ponds, lakes and streams, making do with the natural materials they find.
Damming water does kill some trees, but the dead growth attracts woodpeckers, nesting owls, salamanders, turtles and other species that thrive in the logs and hollow branches.
So what can we do to help beavers continue their important work?
“Demonstrate tolerance. We all have to get along,” Gregory urges. “Sometimes beavers do things that bother us. And there’s nothing wrong with trying to protect things so that beavers don’t have a negative impact on you. But also understand that there is an important role for them too. So the idea of just getting rid of them all isn’t necessarily the best thing either. There’s a balance between us all.”
The story above first appeared in our July / August 2023 issue. For more like it subscribe today or log in with your active BRC+ Membership. Thank you for your support!