Beavers are strict herbivores — they never eat fish. Their diet is the inner bark (cambium) of trees such as aspen, willow, cottonwood, birch, and maple, along with twigs, buds, and leaves, plus a large summer helping of soft vegetation: aquatic plants like water lilies and cattails, sedges, grasses, and ferns. The wood itself is mostly a byproduct; a beaver fells a tree to reach the nutritious growing layer just under the bark and the tender branches in the crown, then uses the leftover timber for dams and lodges.
The North American beaver (Castor canadensis) is the continent’s largest rodent, commonly 35 to 60 pounds, and nearly everything odd and wonderful about it traces back to what it eats. A diet of bark and coarse plant fiber is spectacularly hard to live on — most mammals cannot digest it at all — and the beaver’s solutions to that problem explain its ever-growing teeth, its underwater pantry, and even, indirectly, its dams. For the animal’s full story, start with our complete beaver overview; this article digs into the menu.
Do Beavers Eat Wood?
Not exactly — and the distinction matters. A beaver gnaws through plenty of wood, but what it swallows and digests is mainly the cambium and inner bark: the thin, living layer between bark and heartwood where a tree transports sugars and grows. Cambium is relatively rich in energy and nutrients; the dead structural wood inside is nearly worthless food. So a beaver typically fells a tree, strips and eats the bark and cambium from branches and the upper trunk, eats the buds and leaves, and hauls the peeled sticks away as building material. Those clean, de-barked white sticks along the shore are the leftovers of dinner, not the dinner itself.
Favorite Trees: The Beaver’s Ranked Menu
Beavers have strong and well-documented preferences. Across most of North America the clear favorites are aspen and poplar, with willow, cottonwood, alder, and birch close behind; maple, cherry, ash, and oak are taken readily where preferred species run short. Conifers such as pine, spruce, and fir sit at the bottom of the list — beavers girdle or fell them occasionally, and may eat some in a pinch, but resinous bark is poor food. A beaver colony’s foraging also follows a tidy economic logic: small stems a few inches across are the everyday harvest because they are quick to cut and drag, while the famous big fellings are rarer projects that deliver a whole crown of branches at once. Most cutting happens within about 100 feet of the water’s edge, since every foot of overland travel raises both effort and predator risk.
| Preference | Trees and plants | Notes |
|---|---|---|
| Top choices | Aspen, poplar, willow, cottonwood | Fast-growing, thin-barked species with energy-rich cambium |
| Readily eaten | Birch, alder, maple, cherry, apple | Orchard and ornamental trees near water are very much at risk |
| Sometimes eaten | Oak, ash, beech | Taken more often where preferred species are depleted |
| Rarely eaten | Pine, spruce, fir and other conifers | Resinous bark is poor food; sometimes cut for building material |
| Summer greens | Water lilies, cattails, pondweed, sedges, grasses, ferns | Can make up much of the warm-season diet |
How Beavers Decide What to Cut
Ecologists use beavers as a textbook case of “central-place foraging” — the economics of an animal that must haul every meal back toward a fixed home. The predictions hold up beautifully in the field: close to the pond, beavers cut almost anything edible, including large stems, because transport is cheap; farther from the water they grow increasingly picky, taking only the best species at the easiest sizes, and beyond roughly 100 to 150 feet they mostly stop cutting at all. Studies mapping felled stems around ponds show exactly this gradient — a clear-cut ring near the shore fading to selective, favorite-species-only harvest at the margins.
Beavers also tilt the economics themselves. Where good food lies inconveniently far from the pond, a colony digs canals — sometimes hundreds of feet of them — so that branches can be floated rather than dragged, extending the cheap-transport zone deep into the woods. And felling is less precise than legend claims: beavers do not aim trees at the water. They gnaw the classic hourglass cut and the tree falls where weight and lean dictate — conveniently often toward the light gap over the pond, which is how the myth of the engineering lumberjack got its start.
Reading Beaver Feeding Sign
Beaver work is easy to identify once you know the signatures. Fresh cutting leaves pale, pointed stumps with broad incisor grooves — each tooth mark an eighth of an inch or more across, far larger than a rabbit’s or porcupine’s — surrounded by piles of pale wood chips the size of thick coins. Peeled sticks, gleaming white with all bark stripped, litter feeding areas and shorelines; skid trails and slides mark the drag routes between cutting sites and water. Height is diagnostic too: beavers cut from ground level to about 2 feet (higher off packed snow), so gnawing centered at knee height with chips below says beaver, while bark stripped high in the crown says porcupine, and neat 45-degree scissor-clips on pencil-thin stems say rabbit or hare.
Regional menus track whatever the shoreline offers. In the aspen parklands of Canada and the Rockies, aspen dominates the diet almost to monoculture; in eastern woodlands the mix leans to maple, birch, and witch hazel once aspen runs short; in the Southeast, beavers take sweetgum, willow, and pine along with abundant year-round herbaceous food; and in desert river corridors of the Southwest, cottonwood and willow are nearly the whole story — one reason beaver management and cottonwood conservation are so entangled there. A beaver dropped into any of these landscapes reads it the same way: find the water, then rank the trees.
The Summer Diet: Softer Than You’d Think
Popular images of beavers show them hauling logs, but through the growing season much of the diet is soft vegetation. Beavers relish aquatic plants — the rhizomes and tubers of water lilies are a particular delicacy, along with cattail shoots, pondweed, and duckweed — and they graze shoreline sedges, grasses, ferns, and herbaceous plants. They will also raid crops such as corn and garden produce where fields meet the water. This seasonal shift is efficient: why fell a tree in July when easier, more digestible calories are floating at the doorstep? Woody browse takes over again as green plants die back in fall.
The Winter Pantry: A Food Cache Under the Ice
The beaver’s answer to winter is one of the most remarkable food-storage systems in nature. Through late fall a colony cuts and hauls hundreds of branches, jamming them butt-first into the mud near the lodge until a dense raft accumulates — the food cache. When the pond freezes, the cache sits safely below the ice, and beavers swim out from the lodge’s underwater entrances, pull a stick from the pile, and carry it back to a dry feeding chamber to strip the bark. A well-provisioned cache lets a colony live for months under solid ice without ever surfacing. It is caching on a completely different scale from the buried acorns of squirrels — compare how squirrels handle winter — and it only works because dam-built ponds are deep enough not to freeze to the bottom, one of the main reasons beavers engineer their own habitat in the first place.
How Beavers Digest Bark at All
Bark and cambium are heavy in cellulose, which no mammal can break down with its own enzymes. Beavers manage it the way horses and rabbits do, with hindgut fermentation: an enlarged cecum near the junction of small and large intestine houses microbes that ferment cellulose into compounds the beaver can absorb. Even so, digestion is incomplete, so beavers — like rabbits — practice cecotrophy, re-ingesting soft cecal droppings to run the hardest material through a second time. It is an unglamorous but effective way to squeeze a living from food most animals cannot use.
The famous teeth are the other half of the equipment. A beaver’s four incisors grow continuously for life and are faced with hard, iron-rich orange enamel backed by softer dentine, so ordinary gnawing keeps them sharpened to a chisel edge. A beaver that stopped gnawing would eventually be in serious trouble, as the incisors keep growing regardless — constant woodwork is dental care.
What Beaver Kits Eat
Beaver kits arrive in late spring — typically two to four per litter — and follow a gentle dietary on-ramp. They nurse for their first weeks, begin mouthing leaves and soft twigs brought into the lodge within the first month, and are eating solid vegetation well before summer’s end, though weaning stretches over two to three months. Because young beavers stay with the colony for up to two years, they learn the family’s food economy on the job: which stands get cut, which routes are safe, how the fall cache is built. By the time a two-year-old disperses to find its own territory, it carries a complete education in bark-eating — one reason beaver colonies in good habitat run with such practiced efficiency.
What Beavers Don’t Eat
The most persistent beaver myth is that they eat fish. They don’t — not fish, not frogs, not shellfish, nothing animal. The confusion likely comes from otters, which share beaver ponds and do hunt fish, and from old illustrations that conflated the two. Beavers are as vegetarian as deer or rabbits. They also generally avoid heavily resinous conifer bark, dry dead wood, and — a point of occasional garden relief — most strongly aromatic ornamental shrubs, though no plant near a beaver pond should be considered truly safe when preferred food runs short.
Do beavers eat fish?
No. Beavers are entirely herbivorous, eating bark, cambium, twigs, leaves, and aquatic plants. The fish-eating reputation belongs to river otters, which often live in and around beaver ponds. In fact, the wetlands beavers create typically improve habitat for fish, amphibians, and waterfowl rather than depleting it.
How much does a beaver eat in a day?
Estimates vary with season and food quality, but wildlife agencies commonly cite roughly 1.5 to 2 pounds of woody food per adult per day, more when the diet is soft summer vegetation. Over a year a single beaver may fell or cut several hundred small stems, which is why even a small colony transforms its shoreline so quickly.
Do beavers eat in winter?
Yes — beavers do not hibernate. They spend winter in the lodge, swimming out under the ice to withdraw branches from the food cache they stockpiled in fall. In milder spells they may emerge through open water to cut fresh stems. By late winter, caches run low and beavers often take bark from whatever is closest to shore, including species they usually ignore.
Will beavers eat my garden or orchard trees?
If your plantings stand within about 100 feet of beaver-occupied water, yes — apples and other fruit trees, willows, and young ornamentals are prime targets, and beavers will also take corn and garden vegetables planted near the bank. Individual trunk guards and low fencing are effective protection; we cover the full toolkit in our guide to stopping beaver tree-cutting.
