Hands Down Animals · Printable fact sheet
Beaver
Castor
Quick facts
| Scientific name | Castor |
|---|---|
| Size | 90–120 cm (average), up to 135 cm including tail |
| Weight | 16–30 kg average, up to 40 kg for largest males |
| Lifespan | 10–12 years on average; up to 24 years reported in captivity |
| Diet | Primarily herbivorous: bark, twigs and leaves of deciduous trees (aspen, willow, birch, poplar); also… |
| Habitat | Freshwater rivers, Streams, Lakes |
| Where it lives | Canada, United States, northern Mexico, Alaska |
| IUCN status | Least Concern (both species, global populations) |
| Population | Around 15,000,000 (all species combined) |
| Top speed | 8 km/h |
| Family | Castoridae |
About the beaver
Beavers are the second-largest rodents after the capybara, and the North American and Eurasian species fell trees with chisel-like, iron-hardened orange incisors and build dams of sticks and mud to flood the ground around their lodges. The dam keeps the lodge entrance underwater and out of reach of predators, and the ponds store water and shelter fish, frogs and birds, which is why beavers are called ecosystem engineers. Both species were hunted almost to extinction for their fur; both have recovered and are Least Concern.
Five things to know
- Beavers are the second-largest rodents in the world, after capybaras.
- They are renowned for their dam-building skills, transforming landscapes and creating wetlands.
- Beavers have transparent eyelids, allowing them to see underwater.
- Their incisors are orange due to iron in the enamel, making them extra strong.
- Beavers were nearly driven to extinction by the fur trade, but have since made a significant comeback.
Homeschool unit: Animals homeschool guide — Habitats, adaptations and food chains as a graded unit, with the beaver as one of its worked examples.