Types of Beavers in Maine
Maine has one beaver species: the North American beaver, which was nearly wiped out by 1900 but has recovered to thousands across the state. Once you know what to look for, you can tell beavers apart from other Maine wildlife by their size, flat tail, and dam-building behavior.
More Pages
More beaver pages for Maine
Jump back to the main page for this route cluster.
Maine has one beaver species: the North American beaver, which was nearly wiped out by 1900 but has recovered to thousands across the state. Once you know what to look for, you can tell beavers apart from other Maine wildlife by their size, flat tail, and dam-building behavior.
North American Beaver
The North American beaver (Castor canadensis) is the only beaver species in Maine and the rest of North America. Adults weigh 30 to 60 pounds and measure 3 to 4 feet long, plus a 10-inch flat tail used for swimming, balance, and communication. Their reddish-brown fur is dense and waterproof, ideal for long hours in cold water. All beavers you encounter in Maine are this species.
How common are beavers in Maine?
Beavers are well established in Maine, found in lakes, rivers, and streams across the state. They were hunted to near extinction by the early 1900s when their fur was highly valued, but conservation efforts and reduced trapping allowed populations to rebuild. Today, they are common enough that you have good odds of spotting fresh sign (dam, lodge, gnawed trees, or fresh cut wood) during a wildlife trip to the right habitat.
Physical features that make beavers distinct
Several features set beavers apart from other Maine animals. Their front teeth are large and orange-yellow, visible when they gnaw. Their hind feet are webbed and much larger than front feet, leaving distinctive hand-like tracks in mud. The flat, paddle-shaped tail is covered in scales rather than fur. No other Maine mammal has this combination, making beavers unmistakable once you learn their shape.
Beaver lodges and dams as identification clues
A beaver's behavior is the clearest sign of the species. Beavers build dams across streams, often creating ponds visible from shore or trail. Their lodges (winter homes) are dome-shaped mounds of sticks and mud rising 3 to 6 feet high. You may also see freshly cut trees (pencil-thin saplings to 6-inch diameter logs felled by beaver teeth), bark stripped from the base of trees, and wood chips. These signs confirm beaver presence in an area.
Why doesn't Maine have European beavers?
Europe and Asia have their own beaver species (Castor fiber), which are similar but distinct. North American beavers were never naturally found outside North America, and regulations prevent their import. Maine's beaver is solely the North American species, making species identification straightforward: if you see a beaver in Maine, it is Castor canadensis.
Seasonal changes in beaver appearance
Beaver fur thickens in fall and early winter, giving them a denser, darker look. In spring and summer, after shedding, their coat appears thinner and may look more reddish. Their weight also varies by season, with fall and winter bringing peak weight as they fatten before winter. Despite these seasonal shifts, the species itself remains consistent year-round.
What is a beaver's role in Maine's ecosystem?
Beavers reshape their habitat by building dams and flooding forests, creating wetlands that support fish, waterfowl, and other wildlife. These flooded areas slow water runoff, reduce erosion, and recharge groundwater. Beaver ponds also create habitat diversity, benefiting plants and animals that need marsh and open water. In Maine, beavers are a keystone species, meaning their actions have outsized effects on the landscape.
Are there any non-beaver rodents that look similar?
Maine has other large rodents like muskrats and nutria, but neither resembles a beaver closely. Muskrats weigh only 2 to 3 pounds and have thin, rat-like tails. Nutria are medium-sized (15 to 20 pounds) with round tails and orange teeth. Beavers are much larger, with flat tails and distinct body shape. Once you see a real beaver or its lodge, confusion is unlikely.
For more about Maine beavers
Learn where to see beavers in Maine by visiting specific parks and waterways on our guide to where to see beavers in Maine. To identify individual beavers by their tracks and signs, read our guide to how to identify beavers. Start with the parent guide to beavers in Maine for season timing and trip planning.