10 facts about beavers

Before we get started on their benefits and importance, here are a few beaver facts:

1. Beavers are the second-largest rodent in the world (after the capybara).
2. They were hunted to near extinction in the 16th century for their fur, meat and gland secretions.
3. A beaver’s large front teeth never stop growing. Beavers rely on their constant wood chomping to keep wearing them down.
4. Lodges vs dams. Dams are built in the waterways to slow water flow. Lodges are domed structures you see in the middle of ponds and are where the beavers live. They’re accessed via underwater tunnels which protect the beavers from predators.
5. Beavers have been declared as a ‘keystone species’ as their activities have a significant impact on the landscape and biodiversity of the areas they inhabit. More on this later! They are also believed to play a key part in rewilding parts of the UK and there are many trials underway, and due to start, in the next few years.
6. Beavers aren’t particularly fast on land, but they can swim up to 10 kilometers per hour (6 mph) and can swim underwater for 15 minutes straight without coming up for air!
7. They are said to be second only to humans when it comes to completely changing their environment. Like furry architects!
8. Beavers’ distinctive tails have a multitude of uses, including helping the beaver stay stable when up on its haunches, as a steering device (rudder) when swimming and even storing fat to help them survive harsh winters.
9. Their eyelids are transparent to help them see underwater – like built-in swimming goggles!
10. They have a strong sense of family. They are thought to mate for life, with parents, yearlings (from the previous year) and kits (new babies) all living together. 

A beaver lodge, which will typically be occupied by the entire “family”.

How do beavers help the environment?

Beavers are, without doubt, one of the most environmentally-friendly creatures on the planet. They have the ability to change their own surroundings beyond recognition, in a way that benefits them, the land and many other creatures that live in the same environment. But how exactly is something so small such an environmental champion?

Beavers live a zero-waste lifestyle

Beavers are a great example of top to bottom users. When a beaver fells a tree, it eats the buds, bark and leaves and then uses the trunk and branches to build dams. Any ‘scraps’ that may be inadvertently left behind create what is known as ‘deadwood habitat’. See below for more information on what this means.

The felling of trees along the riverbanks also introduces sunlight to the under canopy, encouraging new growth and plant diversity.

A beaver-felled tree and the wood chippings left behind, which will become, in time, the deadwood habitat.

Beavers are nature’s rewilders

Deadwood habitats are essential in providing food and shelter for countless insects and animals up and down river systems. Attracting insects and other invertebrates, in turn, attracts those higher up the food chain, drawing more creatures back to the riverbanks where there may have been fewer in times gone by.

Dam, that’s good!

The beaver dam is a ‘simple’ structure that has a complex relationship with its surroundings. So how do beaver dams support the ecosystems and benefit the environment?

Defence, defence!

A beaver’s dam slows the flow of water through waterways. Slowing the water in one spot also reduces the flow further downstream which is a benefit during times of heavy rain and flooding. In fact, beavers can help reduce flood peak by up to 30%!

When leaking helps

On the opposite end of the scale, while the dams help to slow the flow of water during times of heavy rain and flooding, their intentional leaks also release water slowly, controlling the base flow of water in a stream. This means that water can stay in place for longer, keeping wetlands wet during times of drought.

Nutrient distributors

The dam, blocking the flow of water through an ecosystem, means that water flows more slowly and stays in one place for longer. This allows nutrient-rich sediment to be deposited instead of continuing to flow. The deposited sediment supports diverse plant life in each part of the beaver’s canal network.

Nature’s water filters

Acting as a natural water filtration system, dams clean the water that flows through them, preventing pollutants from continuing and concentrating in their journey downstream.

Expand and conquer

The introduction of beavers into struggling wetlands gives that area a real opportunity to thrive and grow. As water is retained by the dam, the beavers build lateral canals. While these are built to the beaver’s benefit, to aid movement and transport of foods and building materials, they also aid in expanding the wetlands which, in turn, presents more habitat for wildlife to return to.

Any negatives?

There have been some negative rumblings from some groups about the damage beavers can do to agricultural land. But on the whole, public support for the reintroduction of beavers in the UK is high. So we can expect to see some projects welcoming them soon, and who knows, they might even become a more common sight on our country walks in years to come.

Beavers, the most sustainable engineers in nature

In summary, beavers are amazing ecosystem engineers. They have the ability to restore natural processes at scale very effectively in river and wetland environments. This is done through their dam-building, their excavation of channels and the creation of ponds. They also help to reduce nitrates, phosphates and sediment in watercourses. All of these factors help to prompt a response from the environment, which results in the development of marshy grassland, coppiced woodlands, fen, marshland and boggy areas. Beavers’ activity delivers amazing habitat opportunities for other species like amphibians, water voles, dragonflies and other aquatic life that we used to have so much of but in some cases have all but disappeared in the wild.

According to Professor Driver, beavers are “better than humans at creating mosaics of habitats at scale, that deliver amazing biodiversity benefits”. Pretty impressive, don’t you think?