4 Reasons Why Beavers Cut Down Trees (And How They Do It)

You have heard of the popular tongue-twister: how much wood could a woodchuck chuck if a woodchuck could chuck wood, but let’s change it to beavers and ask ‘why.’ If you are looking for some digestible, but true, reasons why and how beavers cut down trees, this is the piece for you! 

Beavers cut down trees to make food easier to access, prepare lodging, and store fat for the winter. The dams and lodges they build also act as protection from predators and the elements. In general, a beaver can cut through a mature tree in approximately 8 minutes.

Before we continue our discussion of why exactly beavers cut down trees (and how they do so), let’s dive into what a beaver is, exactly!

What Is A Beaver?

Beavers are large, semi-aquatic rodents with a broad tail to aid in swimming and large teeth to help them cut down trees successfully. 

These critters are part of the Castor genus and, within this classification, we most commonly see two different species of beaver: the Eurasian beaver and the North American beaver.

Smithsonian’s National Zoo and Conservation Biology Institute tells us a beaver has orange teeth due to its protective coating and those teeth continue to grow throughout a beaver’s life. This is likely because they chew through so much wood they would otherwise wear their teeth down completely.

Beavers are well-designed to thrive in water and on land, with front paws that are clawed and more easily used to get across terrestrial surfaces, whereas their back paws are webbed and much more akin to those of an aquatic animal.

While you might not expect it, beavers can swim pretty darn fast- up to 6mph, about 3 times as fast as an average human swimmer (though Olympians sometimes swim at a similar 5-6mph.) On land, these critters get a little less refined- walking awkwardly between their clawed front paws and webbed, larger back ones.

Not to worry though, the beaver’s speed (and amazing lung capacity) outweigh any awkwardness they may encounter on land. Beavers can swim for about a quarter of an hour underwater, which we would dare to say is longer than the vast majority of other rodents.

A beaver’s eyesight is not quite up-to-par, so they rely on their ears and whiskers to help them feel out (and ‘hear’ out) spaces. This comes in handy because the dams and lodges beavers build may be secure, but they are also incredibly dark.

Sunset and sunrise may be undetectable markers of time inside a beaver’s lodging because of how thick the wooden walls are. It is a good thing beavers do not need excellent sight, because they certainly would not have good visibility in their homes, regardless.

Also, unlike most other rodents, beavers’ tails are quite broad and can range from being shorter and wider to longer and slimmer, though the general design remains relatively similar across species.

Cool, so now we know a bit more about beavers, but what about different TYPES of beavers?

You can learn even more about beavers in At Home with the Beaver: The Story of a Keystone Species. It provides information about all the species beavers provide habitat to.

American Beaver 

The American beaver is the state mammal of New York- now we bet you did not know that one. (But if you did, props for knowing your stuff!)

This species has a longer and flatter tail, which can help to distinguish this species of beaver. It is also black instead of brown.

The National Wildlife Federation confirms the beaver is the largest rodent in all of the United States, clocking in at 2-3 feet long. Guess what? This length does not even factor in the tail!

These populations are stable, even after a history of being hunted in the Americas for their pelts. In the early 1600s we almost eradicated the animal from what is now New York state, but not to worry- beavers made a comeback and there are now plenty of them all over the continental U.S. 

Eurasian Beaver 

As you might assume after seeing this species’ name, Eurasian beavers populate areas of Europe and Asia.

However, you might not know this once-widespread creature is now found primarily in certain regions of Europe, thanks to centuries of overhunting. 

Certain efforts have been made in recent decades to help beavers become once again populous, but these things take time. 

You can differentiate this species by their broader and more oval-shaped tail when compared to an American beaver.

In the wild, these animals can live between 10 and 20 years, though lifespans fall at the lower end of the range because of environmental factors and poaching.

4 Reasons Beavers Cut Down Trees

Alright, this is it… the moment you have been waiting for! The rhyme and reason of it all. The 4 main reasons beavers do what they do, which will eventually lead us to talk about how they do it.

When it comes down to it, these reasons have to do with survival over comfort. However, the lodges beavers build can be pretty cool and the way they harvest the wood they use is, too.

Here are a few reasons beavers spend so much time and energy working to cut down trees.

Beavers Cut Down Trees For Food

Beavers are herbivores. Haven’t heard the term in a while? It’s okay. 

It means beavers only eat plant products. 

Anything from aquatic plants to leaves off of trees and even the wood itself can make a meal for a beaver.

Funny enough, what they use to build is also their preferred type of food. It seems hard to believe building materials could combine as a meal, but hey, we don’t make the rules!

Beavers cut down trees because they cannot climb them. So, to reach those lush green leaves, they have to bring the top of the tree down to their level. 

At this stage, a beaver might decide to eat more or to break up the branches and twigs along with other tree bits to build a dam or a lodge. 

When you can’t eat, build… right??

You might wonder how there is any nutritional value in these tree bits, but they provide quite a bit of value to beavers. 

Like other plants, they need to be preserved to offer a significant amount of nutrition. This is where the cold water inside dams and lodges comes in handy- it acts as a sort of cooler or refrigerator system to keep these harvested parts of plants cold and full of their nutritional value. 

During the winter, beavers will eat the stems and branches they stored away at earlier times in the year, often as they worked to build their living structures. 

Did you know a beaver’s tail doubles as a place to store fat for the winter? They also use them to warn others of danger when they slap into the water in a certain way.

Beavers Cut Down Trees For Wood To Build Homes

This might be the most obvious of the reasons, the one you were expecting to see. It is true, beavers use a ton of wood for their lodging, but how much do you really know about that?

Beavers are commonly referred to as ecosystem engineers because, as we mentioned above, their lodges truly can affect the entire ecosystem around them.

These creatures are nocturnal and build these structures at night, which makes them appear to be sneaky creatures, while in reality, this is just their most productive period. 

Water levels have to be at least 2 feet deep, but ideally are higher, because they build lodges with hunkering down for the winter in mind. If beavers build a lodge in waters that are too shallow, the bottom half of their home (including those underwater entrances) might freeze during the cold season.

Though lower waters do not work with lodges, they are well-suited for dams that can be built in areas with faster-moving water like rivers, or lower levels of water like small ponds.

These structures are also often works in progress. Beavers may add bedding to the floor of sleeping chambers, create roofs and extra chambers, and make other additions as the need for space grows.

It is common for these creatures to first form a passageway before then digging out a living chamber (the central open space of a lodge) by pushing up on the pieces of wood or even gnawing their way through sections that need to be widened.

Okay, so now that we know a bit more about how lodging works- let’s discuss how beavers might use these spaces for general protection from predators.

Cutting Down Trees Provides Beavers With Protection

Those dams (and also the lodges) beavers build themselves often have many entrances, but they are almost all going to be found underwater. So, natural predators like coyotes, foxes, great-horned owls, and bobcats cannot get in. It can even block otters from entering these spaces.

Beavers design dams to be so much more functional than most people realize, combing style and safety into a secure and sound design. It also helps them stay social with other beavers. 

If danger arises, a beaver can swim quickly into their lodge using those powerful lungs and quick swimming skills. 

On a similar note, if anything occurs inside the lodge, a beaver can escape its home easily and rapidly. 

Dams and lodges are built for easy access by beavers and defense against any predators. 

Just as the beaver is famous for slapping its tail in the water to signal danger, dams are infamous for being the cherished homes and protectors of the species, and for good reason.

This protection extends far past predators and also helps beavers find refuge from the elements. 

When temperatures drop to freezing or below in the winter, beavers have a safe haven underneath the surface. The water may be cold, but beaver’s food storage throughout the summer and fall months has helped them to prepare deeply for a moment like this. 

Storms, ice, and other elements on the outside do not affect the inhabitants of the lodges nearly as much as they would if these animals had to live out in the open air.

Beavers Cut Down Trees To Provide Sustenance for Winter

Beavers do not hibernate, so they need all 3 of the above benefits to be made more accessible during the cold winter months when ground and water freeze over.

During the fall months, beavers will eat more bark than usual to help them fatten up for the cold and long months of winter. 

Even during periods when beavers are not looking to bulk up, tree material comprises the vast majority of their diet, only supplemented by water plants they might find as they swim around. 

During the winter, when resources are low, the natural refrigerator system we have discussed above provides easy and reliable access to food beavers can use to sustain their already-fattened bodies. This helps them to remain active and nourished throughout even the iciest of winter days.

Even if the stockpile runs out- all is not lost!

The University of North Texas describes it like this: if beavers ever run out of food in their naturally refrigerated underwater storage piles, it’s no big deal! Why? They just start eating pieces of their home- easy peasy.

On top of the access to food, let’s not forget the shelters beavers build are complex and protect against more than just predators. Weather-based dangers are also kept safely out of reach of beavers as they stay warm (enough) and safe in their thick wooden lodges and dams.

How Do Beavers Cut Down Trees?

Okay, everything so far is all fine and dandy. Beavers eat, sleep, and live among the trees, but how on earth are those little animals able to cut down entire trees? 

They do not know how to work chainsaws… right? 

Beavers do not need power tools, because they have something naturally powerful on them at all times. 

Beaver’s teeth are no joke. 

Beavers will rapidly chew through the bark and the trunk of a tree, chipping away small pieces of wood at a quick rate, which causes the tree to come crashing down within minutes. 

First, they strip away the bark with this quick gnawing, giving way to the softer wood of the trees, the beaver’s target. 

The way they wear their teeth down while they keep growing makes the shape of their incisors perfectly suited to chomp and chew straight through as many trees as a beaver needs. 

Remember, the reason for this chewing could be a beaver needs to build a new lodge to sleep in, wants to store fat for the winter, needs to be protected from a predator by building a shelter, or simply wants a snack. 

Whatever the reason, it does not take a beaver long to achieve its goal of cutting down any tree- no matter the size.

How Long Does It Take A Beaver To Chew Through A Tree?

Beavers can cut down as many as 200 trees a year, but what does their rate of chewing seriously look like?

One beaver can remove nearly 150 chips of wood from a tree with a 5-inch diameter, which would topple the tree in mere moments. This means it would take about 8 minutes to cut down a relatively mature tree, depending on the species. 

These expert lumberjacks make other species, and machines, look silly.

Beavers prefer trees with a diameter of fewer than 6 inches because the bark of smaller trees is more nutritious. This way, they can reap the benefits of the bark and have a quicker chewing time to cut down the rest of the wood. They use this as food reserves or wood for building lodging. 

A beaver will typically work alone to fell a tree (cut it down), but the colony as a whole will often work to break up sections of the tree. They then divide these sections into food or building materials, and you get the picture!

What Kind Of Trees Do Beavers Prefer?

Beavers use whatever trees they find in their general environment- some popular species of which are poplar, maple, birch, aspen, and willow.

Softwood trees are the most commonly cut down by beavers. 

Since they eat parts of the same trees they use to build, they hold a special preference for those they enjoy munching on. Aspen, poplar, and cottonwood trees are some fan favorites. So, if you have any of these trees and live in a wooded area near any significant aquatic areas- pay extra attention to them. 

Where Are Beavers Found?

In North America, aside from some of the desert regions of the West, beavers can be found all over!

Ponds, lakes, rivers, marshes, wooded areas, streams, and wetland areas are just some environments beavers call home. 

You probably know beavers build dams, but did you know they can also build lodges nearly 7 feet tall, and sometimes even higher?

This is great for beavers because it means they can adapt their environments to fit their needs. Unlike many other animals, beavers can quite literally create new habitats of their own.

It is for this reason beavers need wood, but their motivations are more complex than this alone.

The dams beavers build are made primarily of sticks and reeds. Sometimes, they also add branches and saplings into these wood and mud-walled structures.

These structures can create new habitats because they result in ponds moving, although slowly. They can also support other aquatic life as well as food and water sources for other, larger animals. 

The other structure beavers create, lodges, sit both above and below the waterline, with multiple entrances underneath the surface. However, other parts of the lodge may be above water, such as the sleeping area. 

Beavers typically prepare for and construct these lodges during the summer and winter months to get ready for the winter, but more on this later!

That’s A Wrap!

Well, that’s all we have for you today. We hope you learned a lot of new information about why, how, and when beavers work to cut down trees. 

The primary goal is this piece is just like a beaver’s teeth- not dull!

Learning about the surrounding wildlife not only helps us to live more harmoniously with nature, but it also helps us to understand the reasons we should want to!

Also, knowing how and why beavers cut down trees is just one more piece of the puzzle as we work to grow on our personal and collective tree journeys.

Here are the 4 reasons why beavers cut down trees:

• Beavers eat trees from leaves and twigs to large sticks.
• Beavers build lodging materials from cut down wood.
• Dams and lodges double as predator protection for beavers.
• Trees help beavers store fat when eaten, but also protect them from the elements when lived in, during cold winter months.

Essentially, beavers cut down trees and get a snack, a place to sleep, defense, and shelter from the elements. Not a bad four-in-one deal if you ask us!!

Now, we’ll let you go- thanks for reading and learning with us.

I hope this piece helped you learn something new. As usual, good luck as you continue along your tree journey, and we hope to welcome you again soon!

References

Müller-Schwarze, D. (2011). The beaver. Cornell University Press.

Saunders, D. A. (1988.) Adirondack Mammals. State University of New York College of Environmental Science and Forestry. 216pp.