North American Beaver
The North American beaver is the largest rodent in North America and the second-largest rodent in the world, surpassed only by the capybara. Known for its incredible ability to modify landscapes, the beaver is a keystone species that plays a vital role in wetland ecosystems. With its powerful teeth, waterproof fur, and signature flat tail, the North American beaver is a master engineer of the animal kingdom.
Meet the North American Beaver
Classification
North American beavers are robust, semi-aquatic rodents with thick, brown fur that provides insulation in cold waters. They typically measure between 74 and 90 cm (29–35 inches) in body length, with an additional 20–35 cm (8–14 inches) for their distinctive flat tail. Adults weigh between 11 and 32 kg (24–70 lbs), with males and females being similar in size.
Their most iconic features include large, orange-colored incisors, which grow continuously throughout their lives. These strong teeth allow them to cut through tree trunks and branches, which they use for food, dam-building, and constructing lodges. Their webbed hind feet make them powerful swimmers, while their broad, scaly tail serves as both a rudder in the water and a warning signal when slapped against the surface to deter predators.
Where Does the North American Beaver Live?
Biogeographic Realm: Nearctic
Continents: Americas
Subcontinents: North America
Countries: Canada, United States, Mexico
In the United States, present in: Alabama, Alaska, Arizona, Arkansas [Show all states]
Habitats (IUCN): Forest, Wetlands (inland)
North American beavers are found throughout Canada, the United States, and parts of northern Mexico. They inhabit freshwater environments such as rivers, streams, lakes, and ponds, preferring areas with an abundance of deciduous trees like willows, aspens, and birches.
Beavers are famous for their dam-building behavior, which allows them to create deep, still-water habitats. By gnawing down trees and constructing dams from logs, branches, and mud, they flood areas to form protective ponds. Within these ponds, they build lodges—large, dome-shaped structures made of sticks and mud, with underwater entrances to keep predators out.
What Do North American Beavers Eat?
Beavers are herbivorous, feeding primarily on tree bark, leaves, twigs, and aquatic plants. Their diet varies seasonally—during warmer months, they consume fresh vegetation such as water lilies, cattails, and grasses, while in winter, they rely on the inner bark of trees, particularly willows, aspens, poplars, and birches.
To prepare for the colder months, beavers store food underwater near their lodges. By stockpiling cut branches and logs in submerged caches, they ensure a steady food supply throughout winter when ice prevents access to fresh vegetation.
What Eats North American Beavers? – Predators & Natural Enemies
Despite their large size and protective lodges, North American beavers have several natural predators. Wolves (Canis lupus), coyotes (Canis latrans), bears, and mountain lions (Puma concolor) are among their primary predators. Young beavers, or kits, are particularly vulnerable to predation from foxes, otters, and large birds of prey such as eagles and owls.
To avoid predation, beavers rely on their aquatic adaptations. When sensing danger, they dive into the water and can stay submerged for up to 15 minutes. Their lodges provide an additional layer of protection, with underwater entrances preventing most predators from reaching them.
Behavior & Lifestyle
Beavers are primarily nocturnal and highly social animals, living in family groups called colonies. A typical colony consists of a breeding pair and their offspring from multiple years, with juveniles staying to help raise younger siblings before dispersing to establish their own territories.
Beavers are famous for their dam-building and lodge construction behaviors. They instinctively build dams to create deep-water environments that offer protection from predators and stable access to food. The lodges they construct serve as homes, featuring multiple chambers for sleeping and food storage. These structures are built with an underwater entrance to keep predators out and provide a safe, temperature-controlled environment year-round.
Communication among beavers includes vocalizations, scent marking, and tail slapping. They use scent glands to mark their territory, warning intruders to stay away. Tail slapping on the water serves as an alarm signal to alert colony members of potential danger.
How Do North American Beavers Reproduce?
Beavers are monogamous, forming long-term pair bonds that last for life. Mating typically occurs in late winter (January to March), with females giving birth to a litter of 1 to 6 kits after a gestation period of about 105–107 days.
Kits are born fully furred with open eyes and can swim within a few hours of birth. They remain in the lodge for the first few weeks, nursing from their mother and gradually transitioning to solid food. Older siblings help care for the young, providing warmth and protection. By the time they reach two years of age, juveniles disperse to find their own territories and mates.
Are North American Beavers Endangered? – Conservation Status & Threats
The North American beaver is currently classified as Least Concern by the International Union for Conservation of Nature (IUCN). Once heavily hunted for their fur, castoreum (a secretion used in perfumes and medicine), and meat, beaver populations declined drastically in the 19th and early 20th centuries. However, thanks to conservation efforts, legal protections, and reintroduction programs, their populations have rebounded significantly.
Despite their recovery, beavers still face threats from habitat destruction, water pollution, and conflicts with human infrastructure. Their dam-building activities can flood roads, agricultural lands, and properties, leading to human-wildlife conflicts. In some areas, they are trapped and relocated to reduce conflicts, while in others, non-lethal solutions such as flow devices and fencing help mitigate their impact.
Beavers are essential to wetland health, as their dams create habitats for countless other species, help prevent erosion, and improve water quality. Their ecological importance has led to increased efforts to protect and manage beaver populations, ensuring they continue to thrive in North America’s waterways.
