How Dangerous Is the Beaver?

Beavers, with their large front teeth, small eyes, and flat tails, appear more like the quirky characters of the forest than menacing predators. However, their striking orange incisors can slice through a tree branch as thick as a finger in just one bite. This raises the question: Do beavers pose a threat to humans?

Indeed, under specific conditions, beavers can potentially cause harm to both people and pets.

In 2013, a man in Belarus tried to photograph a beaver but came too close. The beaver bit him, severing an artery in his leg, leading to fatal blood loss.

In 2018, a Pennsylvania man was kayaking when a beaver assaulted his kayak and tried to climb in. Despite hitting it repeatedly with a paddle, the beaver turned its aggression toward his young daughter. He eventually killed the beaver with a stick.

Occasionally, beavers attack due to rabies. This has occurred several times in recent years, such as a 2012 case where two girls in Virginia were attacked by a rabid beaver. Both survived but required rabies treatment.

However, the reality is that beaver attacks are extremely rare, which is why they often make sensational headlines.

"Wild beavers are generally not dangerous," says Michael Callahan, president of the Beaver Institute, an organization focused on resolving beaver-human conflicts through non-lethal means. "Unless provoked, the most aggressive action a beaver will take is slapping its tail on the water to create a loud warning sound."

What Are Beavers Really Like?

Beavers, the largest rodents in North America, typically weigh between 35 and 65 pounds (16 and 30 kilograms). While awkward on land, they are remarkably agile in water, swimming at speeds of up to 6 mph (10 kph). Their oversized lungs enable them to hold their breath for approximately 15 minutes, allowing them to swim nearly half a mile (0.8 kilometer) before needing air. They dedicate their time to constructing dams and lodges for safety from predators and food storage, not plotting harm to humans.

Beavers are found throughout North America, except in desert regions. They are constantly active, felling trees, transporting logs, and building structures in ponds, creeks, and lakes, which likely inspired the phrase "busy as a beaver." Their ever-growing incisors are perfect for their constant chewing. Beaver teeth are orange because they contain iron, making them stronger than, for example, a rat's teeth. This iron-rich composition enables beavers to gnaw through trees with ease.

Beavers are strictly herbivores, contrary to the misconception that they consume fish or other animals, explains Callahan. They nurture their offspring until the young are 2 years old, after which the juveniles leave, find lifelong partners, and construct large lodges for permanent residence. Notably, beavers are among the few species that significantly transform their habitats by incorporating sticks, branches, and mud into their dams.

Do Beavers Help or Hurt the Environment?

The outcomes are typically beneficial for both beavers and other species. "Beavers are incredibly advantageous to the ecosystem. As North America's 'keystone species,' their existence enhances biodiversity," states Callahan. "By constructing dams, beavers transform streams into ponds, creating new habitats that support countless plants, insects, fish, and animals, including endangered species like salmon."

Callahan also highlights that beaver ponds contribute to combating climate change and wildfires, storing vital water, replenishing groundwater aquifers, enhancing water quality by filtering pollutants, and repairing eroded streams to restore healthy watersheds. "Remarkably, beavers provide all these essential ecosystem services at no cost!" he adds.

However, the extensive activities of beavers can sometimes frustrate humans due to the sheer scale of their impact.

"Beaver dams can occasionally flood roads or disrupt human development and land use," explains Callahan. "However, 75 percent of conflicts between beavers and humans can be resolved without trapping or harming the beavers."

Human activity has significantly affected beavers and their environments. Researchers estimate that up to 400 million beavers may have existed in North America before European colonization. However, fur traders drastically reduced their numbers, using beaver pelts to produce fashionable and warm hats, coats, and other garments.

Trappers and hunters were so effective that they nearly wiped out the beaver population. Thanks to contemporary conservation efforts, their numbers have recovered. Today, there are approximately 6 to 12 million beavers in the United States alone.

With proper management, beaver populations are expected to remain stable for the foreseeable future, and their conflicts with humans will likely be limited to occasional flooding issues.