4 Things About Beavers

4 Things About Beavers

Environmental Engineers

Beavers are renowned for their incredible work ethic, second only to humans for how much they alter environments, mostly involving small, slow-running streams, dams, and lodges; all culminating towards forming their wetland habitats.

Forests, for example, are a less fitting landscape for beavers and can get transformed via the aforementioned structures through reengineering. Otherwise, they can burrow near or in ponds and river/lake banks. Their dams naturally lessen downstream flooding by retaining and releasing it slowly; in addition, waterway restoration combats erosion, which reduces siltation toxin pollution as well.

Therefore, they are a 'keystone' species vital for ecosystem function. Because of their productivity, wetland-dependent species receive a place to live rent-free. These can include aquatic organisms such as ducks, water voles, frogs and fish - promoting biodiversity, wildlife tourism and mitigating population decline.

Lodges and Dams

Lodges are massive, enclosed dome-shaped beaver homes, whereas dams protect against water for them. These can take a fair bit over half a month as there are a few tonnes of material to move and place, despite spending a solid ~12 hours a day building and maintaining (they are very protective over their work and rightfully so).

Dams will slow water flow in rivers/streams, creating a separation for a more stagnant pond to form - a calmer area to build lodges in the middle like little islands. For faster flows, dams can have curves to cushion impact more, along with perhaps getting built into the banks for a wider range of coverage.

Restricting the flow helps the pond/lake water with the lodge remain deep - so as to not freeze over in winter, as the food stores are underwater. Pond depth is also crucial since it grants the opportunity for safe retreat away from predators, especially concerning the hidden underwater entrances to the lodge (if the water is shallower, predators could be more likely to find the family).

Lodge territories usually have a food room, a nursing room for the young and the main sleeping area. The cold-water temperature preserves food nutrients (which is most useful when there's less access to trees on land); yet, at the same time, the walls provide insulation while still having small holes for ventilation, plus individuals warm each other. Rooms away from water - like the sleeping area, have reeds and wood shavings for the 'carpet', which absorb moisture and add comfort.

Teeth

As rodents, beavers have ever-growing incisors that are extremely strong. They're kept down by tearing through wood. Beaver incisors have a jagged, chiselled shape for extra sharpness and a sturdy iron enamel coating which gives them an orange colour.

They have a high bite force for their mass and incisor dimensions - however - the sheer toughness and length of the teeth are enough to pass through a person's limb and decimate the blood vessels.

More commonly, their robust teeth and jaws get used to gnaw through wood and carry/manipulate objects for building: such as logs, branches, vegetation, sticks, rocks, reeds and mud for binding. They're so strong they can carry their own weight in their mouths.

To be more efficient, rather than manual labour, they can expand from their main lodge, making long canals/channels leading to food sources, which they float back along.

Moreover, it's convenient their housing and food materials are the same. Beavers are herbivores, eating bark, softer inner tree material, leaves; alongside water vegetation like roots and lilies. They digest the cellulose roughage due to the cellulase enzymes found in the caecum.

Swimming and Water

Beavers are pretty swift swimmers of 5-6mph, symbolised by their anatomical structures of webbed feet and wide + flat tails similar to a rudder. Both heighten surface area coverage to push more water, equating to a higher force production to swim forward. The tail can even slap against the water - creating a warning noise for the family to seek refuge deep underwater against danger.

Underwater, beavers can hold their breaths up to ~15 minutes as they have large lungs, with the average being maybe more like half. They also have stocky bodies with coarse, dense fur with a waterproof undercoat, all for cold temperature resistance. For comfort, the nose and ear valves shut; plus, they possess the nictating membrane eye layer that acts as goggles - lastly, the lips close behind their front teeth to still transport things without drowning.

The tail helps counterbalance the weight of materials held in the mouth due to its relative mass and length compared to the body. So, it's valuable for stability overall and actually allows them to sit upright too.