Beavers Are Animal Kingdom's Best Engineers
- mmcmahon09
- 4 days ago
- 4 min read
Did you know that after humans, beavers are the species that have the largest impact on their environment? If you have taken a walk in the woods, you might have seen trees with what look like a giant bite taken out of them.
Those are beaver chews! Those chews mean that beavers are nearby, and they are renovating their tiny portion of the forest.
Tree-rrific sources
Although they look a little clumsy outside of the water, beavers were made to be nature’s lumberjacks. That large tail that acts as a rudder in the water acts as a kickstand (just like your bike has) to balance on land.
Words to know
Cache: To hide or store away for future use.
Clumsy: Awkward in movement.
Renovate: To restore to a good state of repair.
Sediment: Matter that settles to the bottom of a liquid
Then the beaver uses its large, strong orange teeth to chew trees. Why do they do it? Two reasons. First, beavers eat the trees! Or parts of them, anyway. They munch on tree bark, twigs, leaves and roots as well as herbs, ferns, grasses and aquatic plants. They need the fuel for the second reason: building.
Lodges vs. dams
Beavers build dams and lodges. Lodges are the dome-shaped structures built along banks or sometimes right in the middle of a body of water. Built on a platform, beavers will continue to pile sticks, mud and rocks until a dome starts to take shape. Then beavers chew out the inside until they get their desired interior, which usually consists of a feeding room, a sleeping room and two tunnels.
A beaver family — parents, yearlings and kits — live in this lodge all year. In winter, they cache fresh branches to gnaw on. Sometimes, they will also be neighborly and share their space with a smaller creature like a muskrat.
Dams are like a nice fence that beavers build on their property. However, unlike a fence, it invites animals in, rather than blocking anyone out. To build a dam, beavers stack logs between two riverbanks. Rocks act as anchors to keep the logs stable, and mud and grasses are packed in to fill the gaps. When completed, the dam will slope upstream.
Building this structure is a feat of engineering, but so is maintaining one! Just like any building or bridge, beaver dams and lodges must be maintained over time. Sometimes the sticks give out and a stream of water breaks through. Beavers, recognizing the noise, will patch the hole and continue to maintain its structures for as long as they call that place home.
If a young beaver branching out on its own is lucky, he won’t have to build his lodge or dam from scratch. Sometimes, abandoned buildings are renovated by the next generation of beavers. Others are continuously in use and added to year after year.
The largest beaver dam is in Wood Buffalo National Park in Canada, and it is about the length of seven football fields. Wow!
Why wetlands begin
Imagine a river gets dammed. Water flows and continues to flow unless something, like a dam, blocks it. This water was on a particular path, and even though the dam is in the way, it still needs to flow somewhere.
Beaver dams do not completely stop the flow of the river. However, the water behind will build up and spread out.
See for yourself by trying this: Turn on the faucet in your bathroom sink. The water is flowing at a certain speed. What happens if you take your flattened hand and place it in the middle of the stream? The water goes to either side. Was the water flowing as strong? Probably not. Did a part of the sink that would have otherwise stayed dry get a little wet? Probably!
This slower moving water moves to the ground that was once the river border and partially soaks in. What do you think happens to the earth around this expanding water?
Power of the beaver pond
Beaver ponds, or the wetlands often created by the expanding water, are great for the environment. The beginning of these wetlands starts a chain reaction. The slower water doesn’t wash away sediment from the bottom of the river, so the earth beneath the newly formed beaver pond is healthier.
Moist, nutrient-filled ground is perfect for new plant growth. These new plants create shelter and food for tiny organisms to live, hide and eat, which in turn attracts larger and more diverse animals.
If you were a tiny tadpole, would you like to live along the shores of a shallow pond where you could easily find food and feel the sun? Or a fast-moving river that might sweep you away from your home if you swim too deep?
That shallower pond is inviting to many different creatures, including insects, amphibians, fish, mammals and birds from sparrows to eagles to waterfowl.
Not only that, but that sediment, along with the dams themselves, work as filters for the water. Harmful substances like pesticides are broken down, and water downstream is less polluted. That is good for the animals who eat and live there, and it’s good for us humans, too.
If you were a tall great blue heron looking for lunch, do you think it would be easier to spot fish in a clear pond or a murky river?
Finally, the moist, healthy ground and clean water act like firebreaks and refuges for animals during fires. Fires fueled by dry ground and plants are often weakened or extinguished when coming near a beaver pond. While fires are healthy for some environments, too many can be dangerous!
With all that a beaver can do, it’s no wonder that fans of these industrious rodents are called “beaver believers!”
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