Science

Bring back the beavers?

Beavers to be reintroduced to the UK. Source: Cliff (via Flickr)

By Jemma Powell | Science Editor

Up until the 18th century, beavers were common place throughout the UK. Sadly, they were driven to extinction after merciless hunting for their pelt, meat, and scent glands. This lead to vast ecosystem change, including complete loss of waterbodies and decline in other species such as otters and kingfishers.

After 400 years, is it time to bring back the beaver?

Why are beavers important?

Beavers are the second largest rodent in the world (after capybaras) and are a keystone species. This means they have a disproportionally large effect on its natural environment- without them, the system would fall apart.

“We weren’t aware of their true value’’

With their characteristic prominent front teeth and large flat tail, beavers are perfectly adapted for what they do best. Building dams.

Damming climate change

Dams are an effective and cost-efficient way of mitigating environmental disasters. When a beaver arranges sticks and debris across a river, it forms a dam, blocking water from flowing downstream in the same way.

Instead, some of the water floods the local flat land, creating deep pools of water filled with life. The intricately laid twigs act as a filter, allowing complex life to flourish in the cleaner water downstream.

Dams reduce flood impact by up to 60%, and they provide a water supply in times of drought as well. The wetlands surrounding a newly dammed river create hoes for otters, water voles, kingfishers and many more, while the damn itself can home over 2000 different invertebrate species!

Beavers also bring financial benefits. For example, the region of Winzer in Bavaria was prone to flooding. To counter this, the government had planned to install a man-made dam, costing over one million euros. At the same time, recently returned beavers had been building their own upstream. This slowed the flow of water, and mitigated flood damage before the contractors could start building the concrete one. Fewer than 50 beavers saved the town more than €650,000.

Beaver damage

There are some arguments against the reintroduction of beavers. The main concerns surround farmers and their land. Beavers naturally making wetlands is great for the environment, but they could result in crops of grazing fields being flooded.

Another issue is beavers could cause unwanted tree felling, especially in protected areas. Wood for dams is acquired by gnawing down trees and this can cause them to collapse early.

However, there are easy solutions to these issues. Flooding can be avoiding by adding drainage channels and pipes into the saturated land, causing the water to rejoin the river lower down. Alternatively, farmers could be given government subsidies and funding to reimburse their lost land.

Tree felling can be prevented by placing wire mesh (which beavers can’t eat through) around protected tree trunks. Also, native British trees such as alder or willow evolved alongside beavers millions of years ago. These are therefore adapted to beaver gnawing by quickly re-growing from felled stems or cuttings, leading to more trees in the same area.

Rewilding in Britain:

Some beavers are returning to Britain naturally. Roughly 200 individuals were found along the river Tay in Scotland in 2001. As their numbers started to grow, beavers were proclaimed as a native species in Scotland within the decade, and were granted European protected species status.

Between 2017 and 2021 small groups of beavers were released in controlled areas of Wales, Cornwall, Devon and Dorset. While the impact of these reintroductions haven’t been fully investigated yet, they’re predicted to be a success. There’s even a governmental consultation ending on the 17th of November about the public’s opinion on beaver reintroduction.

Back for good?

So, beavers purify water, create new habitats, increase biodiversity, and reduce flooding. Maybe we’ll soon be seeing them around the countryside in much larger numbers!

Jemma Powell Science and Technology

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