Types of Beavers in Missouri

Yes. The North American beaver (Castor canadensis) is the only beaver species found anywhere in Missouri. There are no other native beaver species in the state, and no introduced or exotic beaver species have established populations. If you encounter a beaver in Missouri, it is Castor canadensis. This species is found from coast to coast across North America and has been present in Missouri for centuries, though populations were depleted by fur trapping in the 1800s and early 1900s. Today, beaver populations have recovered in many Missouri watersheds.

North American beavers are large, stocky rodents with a distinctive appearance. They typically weigh between 30 and 60 pounds, though some individuals reach 70 pounds. Their fur is dense and dark brown, sometimes appearing nearly black when wet. The most recognizable feature is the flat, paddle-shaped tail, which is hairless and covered in leathery skin. Their front teeth are large, orange-yellow, and continuously growing. Their eyes are small and positioned high on the head, and their ears are also small and rounded. Their hind feet are webbed for swimming, while their front feet have sharp claws for digging and manipulating wood.

When a beaver is swimming, look for a large, rounded head moving through the water, often followed by a V-shaped wake. You may see just the top of the head above the surface. The paddle-shaped tail is sometimes visible slapping the water as a warning signal. Beavers move deliberately and steadily through water, unlike muskrats or nutrias, which move with quicker, more erratic motions. Beavers also produce a distinctive splash when they dive, sounding like a loud slap on the water caused by the tail hitting the surface.

North American beavers are the second largest rodents in the world, surpassed only by capybaras in South America. In Missouri, an adult beaver is substantially larger than a groundhog, muskrat, or nutria. An average beaver weighs 40 to 50 pounds, while a large groundhog weighs only 5 to 14 pounds, and a muskrat weighs just 2 to 4 pounds. This size difference is one of the easiest ways to distinguish a beaver from other aquatic rodents you might encounter in Missouri waterways.

Beaver presence is often easier to detect through signs than by spotting the animal itself. Look for freshly cut trees and saplings with a distinctive pencil-point appearance where beavers have gnawed through the wood. Tooth marks in the wood will be visible, ranging from less than an inch to several inches in width. You may also find beaver dams made of sticks, mud, and branches, or lodges that appear as dome-shaped mounds of wood and mud in the water. Footprints in mud along the water's edge show webbed hind feet and smaller front feet. Droppings, called scats, are rare to find but appear as small wood chips or sawdust-like pellets.

While North American beavers are typically dark brown, color can vary slightly from individual to individual. Some beavers appear almost black, while others display a more reddish-brown or tan hue. This natural variation does not indicate a different species or subspecies, just individual differences within the population. Beavers living in clear water may appear darker because the fur absorbs more light, while those in murky water may appear lighter due to sediment and algae clinging to their fur.

Yes, beavers vocalize in ways that can help you confirm their presence. They produce various sounds including hisses, growls, and tooth chatters when communicating or feeling threatened. The most dramatic signal is the tail slap on the water, which creates a loud warning sound that echoes across the water and can be heard for a considerable distance. This tail slap alerts other beavers to danger. You may also hear the sound of beavers moving through water or hear them gnawing on wood, particularly at night when they are most active.

Beavers, muskrats, and nutrias all live in Missouri waterways, but they are easily distinguished by size. A beaver is much larger, weighing 30 to 60 pounds, while a muskrat weighs only 2 to 4 pounds and a nutria weighs 15 to 20 pounds. Beavers have flat, paddle-shaped tails, while muskrats have thin, compressed tails and nutrias have round, scaly tails. Beavers also build dams and lodges, and they fell large trees, behaviors that muskrats and nutrias do not exhibit.

Beavers in Missouri are found in rivers, streams, ponds, and lakes throughout the state, preferring areas with flowing water and deciduous trees like willows, aspens, and cottonwoods. They thrive in the Ozark region, along the Mississippi River, and in the Missouri River floodplain. They require water deep enough to provide cover and access to trees for food and building material. They avoid fast-moving, rocky streams and prefer quieter sections where they can dam and create the pools they need.