THE ANIMAL FILES

North American beaver

Castor canadensis

A beaver canal can turn a heavy log into a floating load.

North American beavers modify waterways with lodges, dams and canals. They eat plants, including herbaceous foods and woody tissues, rather than fish. Their building changes access to resources and creates watery habitat used by other organisms.[1]

Follow the evidence ↓
North American beaver
Image: Vlad Podvorny · Commons · CC BY 2.0
Food
Herbaceous and woody plants[1]
Transport
Canals can float wood toward ponds[1]
Warning
Tail slaps on the water[1]

A canal extends the route

Beavers push through soil and vegetation to develop canals. These routes allow collected wood to float toward a pond and can reduce overland exposure. Dams may maintain water levels within the canal network. The construction therefore influences how materials are moved as well as where the animal swims.[1]

Food changes with the season

Actively growing herbaceous plants can dominate during the growing season. In winter, woody material and stored food become more important. Bark, cambium, shoots, leaves and aquatic vegetation all occur in the diet. Living among fish does not imply feeding on them; the beaver’s food system is plant-based.[1]

A home with watery entrances

Lodges are assembled from woody materials and mud, with entrances below water and resting spaces above it. Tail slaps signal danger. Ponds and wetlands created by beaver activity offer new habitat for aquatic plants and animals, although effects differ with setting and the organisms already present.[1]

A COMMON MIX-UP

Do beavers build ponds in order to farm fish for food?

No. They are plant-eaters; fish can benefit from habitat changes without being their intended crop.[1]

TRY A LITTLE REASONING

Why float a log through a canal rather than move it entirely over land?

Reveal the explanation

Water supports the load and the canal creates access between the resource and pond, reducing overland transport.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Castor canadensis (adapted and translated; exact revision)
  2. NCBI Taxonomy — Castor canadensis (identity and game lineage)

Last fact check:

One discovery leads to another

GroundhogA groundhog’s winter is an active physiological change, not just a long nap.Marmota monax ↗Golden hamsterThose swollen cheeks are transport bags, not a giant swallowed meal.Mesocricetus auratus ↗Mongolian gerbilA grassland home with more than one exit.Meriones unguiculatus ↗