A mystery solved: Scientists discover why beavers build dams and cause disasters

Beavers are famous for building dams with trees and branches that they cut with their strong front teeth and also use grass, stones and mud to reinforce these structures.

However, a question always haunts the same question, why do beavers build dams? They live there?

Beavers build dams to stay safe, which is especially difficult considering their awkward body shape and lanky nature.

Why do beavers build dams?

“Beavers are stinky 40- to 80-pound sacks of meat with very short legs,” explained Chris Jordan, a fishery biologist at the National Oceanic and Atmospheric Administration’s (NOAA) Northwest Fisheries Science Center in Newport, Oregon.

This makes them easy prey. “When beavers are on the ground, they are very clumsy and vulnerable, like big waddling pieces of chicken that any predator would be happy to eat.“explained Emily Fairfax, ecohydrologist at California Channel Islands State University in Camarillo, California.

Fairfax added that “when in the water, beavers are nearly invincible. They are excellent swimmers and they can hold their breath for 10-15 minutes“. By building a dam, you create a pond, and that pond is your safety zone.”

These bodies of water are deep enough for beavers to “hide from predators, like pumas, bears, wolves and coyotes”Jordan explains.

Also, himdams can also flood areas to bring beavers closer to their main food source. This includes tree bark, leaves and branches as well as aquatic plants, according to a King County, Washington information booklet.

On the other hand, “beavers dig vast networks of canals behind their dams to distribute the water,” Jordan explains. This can safely bring them closer to trees, but also helps “return larger chunks of food and building materials to their shelter, prey and food supply.”

While dams protect beavers, they do not live within these structures. According to the online database Animal Diversity, a site of the University of Michigan, they usually live in oven-shaped shelters made of sticks, moss and mud, built on the banks of ponds.

In these shelters they reside in family groups, known as colonies, consisting of an average of five beavers, says the King County page.

The Eurasian beaver (Castor fiber), which lives in Europe and Asia, is slightly larger than the American beaver. However, it also builds dams, shelters and canals.

Not everything is bad. Indeed, beaver dams help ecosystems as they not only benefit their creators, but many other species as well.

“Beaver dams help slow down the water and keep it in the landscape longer” Fairfax explained. “This transforms simple streams into thriving wetland ecosystems. The amount of food and water available in their wetlands makes them ideal habitats for many different species. That’s partly why beavers are a species known as a keystone.”