Why Beavers Are So Obsessed With Building Dams

Find out how beavers construct their magnificent dams and what effects they have on the environment.

The longest beaver dam in the world is located in Canadian woodlands. This 850-meter-long construction has drastically changed the area, creating a pond with 70 million liters of water. It is large enough to be visible in satellite images. However, dams of any size can significantly alter their surroundings. So how precisely do beavers construct these stunning structures? Glynnis Hood conducted extensive research on this.

The creators of this wooded kingdom are well-housed in this roomy setting. However, dams as small as one hundredth the size of this one can nonetheless significantly alter their surroundings. What does a beaver do to remodel a forest, and how can they create such stunning structures in the first place?

Take a look at this beaver in the northwest of the US. He is a proud representative of the second-largest rodent species in the world, standing just under 2 feet tall. While he is vulnerable to predators on land, once he has constructed a lodge, he will have a huge moat to protect him. He is unable to just erect a dam anywhere. Our beaver investigates densely wooded areas after hearing the sounds of running water in quest of a medium-sized stream that is neither too steep nor too deep. He finds a creek with a soft, muddy bottom after leaving one building site due to its rocky bottom.

Along the edge of the creek, he builds a little bank out of plants, mud, and sticks. Then, our beaver eats the surrounding wood into robust sticks with a bite that is nearly three times as powerful as any other mammal of this size. He then rolls them into the water and drives spikes into the smooth streambed. Beavers may build dams in a variety of designs, but in order to diffuse the forceful rushing water, our beaver chooses a concave dam. He also layers in big boulders to fortify the places where the water runs the strongest.

The speed at which these devoted builders can construct a dam depends on the size of the dam, the speed of the stream, and the number of beavers used. Beavers have occasionally overnight rebuilt dams that people attempted to demolish, sometimes making them much larger than before. The beaver's project is only a few meters long, like most dams. And building this dam by yourself can take several days. But as soon as the building crosses the channel, his wet house starts to fill.

He will extend the dam as the pond expands to prevent water from flowing around the sides. Although some is allowed to escape downstream, this relieves pressure on the dam and controls water levels in the pond. The size of the beaver's territory increases with pond size. Beavers can easily acquire food near shorelines since they have the capacity to hold their breath for up to 15 minutes. Our beaver gathers an astonishing amount of food for the winter during the autumn while simultaneously looking for someone to share it with.

Although beavers are ferociously territorial, they also form lifelong bonds. Our young beaver couple divides their time between having a brood and going to the food cache with their lodge's special entrance when the pond freezes over. The juveniles will help strengthen and build their dam throughout the summer, gather food, and keep an eye on their smaller siblings.

These young beavers will disperse to find their own territory and partners after two to three years. However, their ancestor dam has a long lifespan. Beavers who moved in after the ruling family left or new beavers who moved in continue maintenance work. There are certainly plenty of neighbors; in some areas, there are up to 40 beaver dams for every kilometer of stream. For the nearby wildlife, which is greatly dependent on these semi-aquatic engineers, this is excellent news.

Different species of ducks might find refuge and a place to nest in lodges. Along with connecting water bodies, beaver channels increase the biodiverse zones between water and land. Beaver construction projects also assist humans. Their ponds contribute to the replenishment of groundwater reserves in part by generating vast areas of surface water. Beaver dams also help to reduce floodwaters, just like their man-made counterparts. These ecosystem engineers therefore have a significant impact downstream just by acting on their innate impulses.