Types of Beavers in Oklahoma

North American beavers are the only beaver type found in Oklahoma. They were historically present across the state but nearly disappeared from hunting and trapping in the 1800s. Reintroduction and natural recovery over the past century have restored populations, especially in forested areas near water. Beavers are the second-largest rodent in North America after the porcupine, and they're the only species you'll encounter if you're searching for beavers in Oklahoma.

Adult beavers in Oklahoma typically weigh 35 to 60 pounds, with some exceeding 70 pounds. They measure 3 to 4 feet long from head to tail, and their flat tail adds another 10 to 15 inches and accounts for much of their distinctive shape. Males and females are similar in size, so weight alone won't tell you the sex. When you see one swimming or moving along a streambank, the broad, paddle-like tail is the easiest way to confirm it's a beaver and not another large rodent or mammal.

Beavers have dense brown fur, small rounded ears, and prominent front teeth that never stop growing. Their hind feet are webbed, and their tail is flat and scaleless. From a distance, a beaver might be confused with a muskrat, but beavers are much larger, have a wider tail, and move differently in water. Beavers are often slower and more deliberate swimmers than muskrats. On land, their stocky body, short legs, and waddling gait are unmistakable once you've seen one. The front teeth, which can be 20 millimeters long, are bright orange due to iron deposits in the enamel.

Beaver dams, lodges, and felled trees are the most obvious signs. Beavers cut trees by chewing them down at an angle, leaving characteristic tooth marks and wood chips at the base. Trees 2 to 6 inches in diameter are their preference, though they'll tackle larger ones. Dams can be simple stick-and-mud structures or complex engineering projects spanning 30 feet or more. Lodges look like mounds of branches and mud rising from the water. Fresh gnaw marks, recently peeled bark, and muddy trails along the streambank all indicate active beaver presence.

Look for wet wood chips and recently gnawed stumps with sharp, chisel-like cuts still light in color. Fresh mud on dams and lodges is moist to the touch and hasn't dried to a hard gray crust. Beaver tracks in soft soil or mud show five toes on the hind foot and four on the front, with the distinctive webbed hind foot print being wider than the front. Scent mounds, small piles of mud with castoreum (a scent gland secretion) applied on top, mark beaver territory and are often found near water's edge. These mounds can be refreshed seasonally and are a sign of an active colony.

Beavers are monogamous and live in family colonies led by a breeding pair. A typical colony has 5 to 8 individuals, including yearlings and kits from the current and previous years. Colonies are territorial and defend their area against other beavers. A single dam and lodge may house the whole family, or they may maintain several dam sites along the same stream. During spring, kits are born in the lodge, and by summer they're learning to forage and help maintain the dam. By fall, yearlings often disperse to find their own territory.

Male and female beavers look nearly identical in the field. Females are slightly smaller on average, but there's enough overlap that size alone won't reliably tell you the sex. Both sexes have the same coloring, tooth size, and body proportions. The main behavioral difference is that females tend to spend more time in or near the lodge during spring and early summer when caring for kits. Unless you observe mating behavior or trap-mark-recapture data, determining sex by sight alone is difficult. Fur and body shape are uniform across both sexes.

A lodge is the beavers' home, an above-water structure built from branches, mud, and vegetation. The lodge has an underwater entrance tunnel that provides protection from predators. The interior chamber is kept dry and lined with wood chips. A dam, by contrast, is an engineering structure built across a stream to raise the water level. The higher water protects the lodge entrance from freezing and gives beavers better access to food sources on the flooded bank. A single colony usually maintains one or more dams upstream of their main lodge, and may have satellite lodges or bank burrows at secondary sites.

Beavers are active year-round, but their behavior changes with season. Spring brings kit births and increased lodge maintenance. Summer and early fall are peak dam-building and food-gathering times as beavers stockpile branches for winter. Late fall through winter, beavers are less visible but still active inside the lodge and foraging from underwater food caches. The period from August through October shows some of the most obvious landscape changes, with fresh-cut trees and active dam work. However, winter is often the best time to spot beavers themselves because ice and snow reveal tracks, and they surface more frequently at breathing holes in the frozen water.

Beavers are primarily crepuscular and nocturnal, most active from dusk through dawn. During the day, they rest in the lodge and emerge in late afternoon to early evening. Daytime sightings are less common but do happen, especially in areas with minimal human disturbance or during spring when kits are learning. Your best chance to see a living beaver is during the hour or two after sunset at a quiet stream or by waiting near a lodge before dark. Early morning can also yield sightings. If you're visiting the Wichita Mountains or Red River areas, plan your beaver-watching for evening hours to maximize your odds.

Beavers are herbivores and prefer the bark and cambium of deciduous trees. Aspen, willow, cottonwood, and birch are favorites, but they'll also eat alder, maple, and pine. You'll recognize their feeding activity by looking for debarked branches and stacked wood piles near the lodge or dam. In water, submerged branches are stripped of bark and stacked as a winter food cache. Beavers also eat water plants, grasses, and aquatic vegetables. In Oklahoma's mixed forests and riparian zones, willow and cottonwood are common targets. Freshly peeled branches with bare white wood and scattered bark chips near the water are a sign of recent feeding.