Beavers are adorable creatures living in the wetlands. They spend the majority of their time in the water, building dams or lodges, eating, mating, and sleeping.
On land, they are often spotted chewing on trees and cutting them off with their strong teeth. This leads people to believe that beavers eat the trees whole.
But do beavers eat wood, or do they only cut off trees?
Beavers do not eat wood. However, they eat tree parts, including bark, leaves, and twigs. Their gut microbiome is adapted to digest cellulose. That’s why beavers can eat woody vegetation other animals can’t eat. Beavers also gnaw through wood to cut off the trees that they will use as a building material.
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Do Beavers Eat Wood Or Just Chew It?
The image of beavers munching on trees is well ingrained in most people’s brains. These rodents have incredibly strong teeth and jaws that enable them to chew down trees of all sizes. However, beavers don’t eat the wood. They only chew their way through it and let the pieces fall from their mouths without swallowing them.
The preconception that beavers eat wood comes from the fact that they cut down trees. However, even if beavers don’t eat wood, they store tree parts in the bodies of water where they live and to consume them in the winter.
Do Beavers Eat Bark?
Beavers eat tree bark, cambium, and twigs, alongside tree leaves, stems, and buds. However, as herbivores, beavers prefer to eat soft, herbaceous plants rather than woody vegetation, if they are available. Throughout spring and summer, a beaver’s diet consists mostly of grasses, leaves, and aquatic plants such as water lilies and cattails.
These rodents also consume pondweed as they are swimming, as well as aquatic plant roots and tubers.
On land, beavers also eat berries and a variety of other fruits, including apples and cherries.
In late summer or early fall, beavers start to build food caches on the bottom of the pond, generally right under their lodge. These food caches consist of woody species and constitute the primary food source throughout winter. Studies suggest that beavers prefer woody vegetation during the cold season for its ability to be preserved.
In another study, researchers have also found that beavers soak woody vegetation like bark and twigs in water before consumption to improve their palatability. This should not come as a surprise, considering that beavers always taste the trees in their area before deciding which to feed on.
Woody stashes, alongside whatever herbaceous vegetation is available during winter, provide beavers with the necessary amount of calories for subsistence.
Related: What Do Beavers Eat?
How Many Calories Do Beavers Need?
Beavers are active animals, but their metabolism is rather slow. On average, a 26-pound beaver requires between 760 and 850 kcal – the equivalent of about 1.5 lbs. of fresh aspen – per day during summer. However, this is the minimum number of calories required for subsistence.
The table below shows the optimal amount of food a beaver should eat.
| Reason | Number of calories/day | Quantity of fresh aspen/day |
|---|---|---|
| Subsistence (summer) | 850 kcal | 1.5 lbs. |
| Subsistence (winter) | 1245 kcal | 2.2 lbs. |
| Growth | 2040 kcal | 3.6 lbs. |
Note: The figures above are calculated for a 26-pound adult beaver. Kits and older or larger beavers may require a different calorie intake.
Why Do Beavers Cut Down Trees?
Beavers cut down trees to use them as a building material and to feed on their twigs and leaves. The rodents can gnaw through trees of all sizes. While they prefer smaller trees (which are easier to cut and carry), beavers will start cutting the larger ones once all smaller trees have been used.
If the tree is too large, the beaver will generally proceed to cut it into smaller pieces that are easier to drag to the pond. In some cases, the entire beaver family could work together to slice and move a particularly large tree.
Once the tree is cut, beavers eat some of the parts and use the rest to build dams across streams. These dams block or slow down the flow of water and create ponds where the rodents can live protected from predators.
Beavers don’t live inside the dam but use these artificial ponds as places where to build lodges.
While the rodents use larger branches and tree trunks to build the dam, the lodges are generally made of twigs, sticks, mud, and rocks. Beaver lodges have an underwater entrance that prevents predators (wolves, mountain lions, and coyotes) from entering.
In addition to feeding and building shelters, beavers also gnaw on trees to keep their teeth from growing too much.
Beaver Teeth Adaptation
Beavers are incredibly well adapted to the environments they inhabit, and one of these adaptations involves their teeth.
Because the rodents gnaw on trees constantly, their incisors wear down easily. That’s why the teeth continue to grow throughout the beaver’s entire life. Without chewing wood, the teeth would grow too long and could impair the animal’s ability to eat.
Another peculiarity about the beaver’s teeth is their color. Beavers have dark yellow, orange, or reddish teeth. This hue is due to the high level of iron in their tooth enamel. Both the color and the iron in their teeth set beavers apart from other rodents that have white teeth and magnesium as the main component of their tooth enamel.
While the iron changes the color of a beaver’s dentition, it also makes the teeth more resistant to acids and mechanical stress, improving their ability to chew on wood and cut down trees.
How Do Beavers Store Food For Winter?
We mentioned that beavers stash sticks and branches in food caches to use during winter, but how do they do that?
It all starts in late summer or early fall, when beavers start cutting, transporting, and piling sticks and branches on the bottom of the pond. The caches are generally built as close as possible to the main lodge entrance.
Beavers initially make a cache base by sticking the butt end of branches into the mud. Then, they weave the other branches and sticks into the pile creating a solid structure that resists water currents. Food caches are generally big enough to provide sustenance to the entire family throughout the winter – a colony of beavers can store as much as 2,500 pounds of edible woody vegetation before the pond becomes frozen.
The higher temperature inside the lodge prevents the lodge entrance from freezing. Thus, beavers have access to their food stash throughout the cold season, carrying the sticks into the feeding chamber of the lodge to gnaw on succulent bark.
However, once the ice forms, the beavers can no longer leave their lodges and only rely on the food cache and their own fat to survive. For this reason, most beavers start to put on fat during the fall. Fat provides both thermal insulation and energy when food supplies become scarce.
This behavior is generally observed in beavers living in cold climate areas. Beavers living in warmer climates have no need to pile food for winter, and they rarely do so since they can leave the lodges and feed on soft vegetation all year round.
Conclusion
Beavers use trees to build dams and lodges. They cut them with their sharp teeth; yet, beavers don’t eat wood. When possible, beavers prefer eating soft vegetation such as grass, clover, or tree leaves.
They also eat bark and cambium, which is a softer tissue between the bark and the tree’s wood core. Both the bark and cambium provide the animal with the sugar, vitamins, and minerals needed for sustenance. However, the woody vegetation is mostly consumed in the cold season.
That sums up the topic of “do beavers eat wood”.
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