Unironically, beavers are genuinely one of my favorite animals! With their chunky bodies, fluffy fur, five-toed webbed hind feet, five-finger hands, orange bucked teeth, and paddle-shaped tail, what’s not to love about them? They’re so cute! I recently watched Zootopia 2 in theaters, and there was a beaver character named Nibbles! I was THRILLED to say the least! I’ve never seen one in real life, so it’s on my bucket list to meet one someday. 

Here’s a picture of my beaver squishmallows and bidoof plush! The beavers even have a paddle tail if you look closely. Bidoof is a Pokémon inspired by the beaver, and it evolves into Bibarel!

Intro to Beavers

Beavers are large, semi-aquatic rodents of the Northern Hemisphere (Brazier et al., 2020). There are two existing Beaver species: the North American beaver (Castor canadensis) and the Eurasian beaver (Castor fiber) (Brazier et al., 2020). We’re able to tell the difference between the two species based on the number of chromosome pairs: the Eurasian beaver has 48 pairs while the North American beaver has 40 pairs (Lavrov, 1983). Their distinctive features, such as the flat, paddle tail, webbed hind feet, constantly growing teeth, and dense fur, allow them to perform specialized behaviors: damming and tree felling that can transform landscapes, habitat, and water management (Brazier et al., 2020). Beavers use their construction ability to protect themselves from predators; they use their teeth to collect branches and trees to build their dams (“Beavers work to improve habitat”). 

Beavers as Ecosystem Engineers

Beavers are considered ecosystem engineers because their construction capabilities can alter, maintain, or create habitats by redistributing biotic and abiotic resources for themselves and other species (Rosell et al., 2005). There are three main types of lodge structures that beavers can build, and they select their lodge location based on water depth and bank characteristics (Rosell and Campbell, 2022). These lodges are where beavers take shelter, and beavers create underwater entrances to get to the dry living space, often called the chamber, which is where they rest, raise their young, and stay safe from predators (Rosell and Campbell, 2022). The three types are island lodge, bank lodge, and stick lodge (Rosell and Campbell, 2022). The island lodge is more commonly found in North America, and beavers build this type of lodge when the bank is low (Rosell and Campbell, 2022). Because the bank is low, beavers can’t dig a burrow into a bank, so they build upwards (Rosell and Campbell, 2022). “Bank lodges are found on the water’s edge and built around a burrow dug into the bank” (Rosell and Campbell, 2022). Finally, stick lodges are built from material extending from the shoreline (Rosell and Campbell, 2022). To create a more efficient access to food and building resources, beavers dig shallow channels, canals, which extend from beaver ponds (Brazier et al., 2020). Beavers build dams to raise the water level: ”habitats with deep, slow-flowing water keep them safe from predators” (Brazier et al., 2020). There are two types of dams that beavers may build: the primary and secondary dams (Brazier et al., 2020). The primary dam maintains the main lodge pond, which is much larger than the secondary dams; the secondary dams improve mobility and serve to move woody materials (Brazier et al., 2020). 

Beavers are keystone species (Brazier et al., 2020). They literally change their habitat with their engineering instincts for their survival and needs, thus directly changing their habitat’s ecology. If you like to learn more about beavers in a more entertaining format, I highly recommend checking out Lindsay Nikole’s video about beavers! She’s one of my favorite animal content creators!

Sources:

Brazier, R. E., Puttock, A., Graham, H. A., Auster, R. E., Davies, K. H., & Brown, C. M. (2020). Beaver: Nature’s ecosystem engineers. WIREs Water, 8(1). https://doi.org/10.1002/wat2.1494

Beavers work to improve habitat: U.S. Fish & Wildlife Service. FWS.gov. (2025, December 1). https://www.fws.gov/story/beavers-work-improve-habitat

Lavrov, L. S. (1983). Evolutionary development of the genus Castor and taxonomy of the contemporary beavers of Eurasia. Acta Zoologica Fennica, 174, 87-90.

Rosell, F., Bozsér, O., Collen, P., & Parker, H. (2005). Ecological impact of beavers castor fiber and castor canadensis and their ability to modify ecosystems. Mammal Review, 35(3–4), 248–276. https://doi.org/10.1111/j.1365-2907.2005.00067.x

Rosell, F., & Campbell-Palmer, R. (2022). Beavers: ecology, behaviour, conservation, and management. Oxford University Press.