Beavers fell a tree by gnawing at the base until the trunk starts to look like two pencils balanced point to point. Eventually, there is not enough wood to hold the tree upright and it falls. Then the beaver strips the tree and uses the branches and leaves for food or dam building. These pencil stumps have not been seen in the wild for over 300 years since beavers became extinct in Britain.

“Became extinct” is too gentle a phrase to describe the violent demise of beavers. They were killed, every last one, by human hunters who considered that the beaver’s body parts, mainly skin and glands, had more value than the living creature. They were slaughtered into extinction.

Fortunately, in the latter half of the 20th century, ideas of preserving wildlife and its habitat became popular and found their way into law. In the 21st century, attention has turned to try to undo the damage of the past and re-introduce some of the creatures once native to Britain. If you read about re-introductions and wilding in Britain, sooner or later you will encounter the name, Derek Gow.

Gow is a conservationist who operates a farm on Dartmoor. He began re-introductions by breeding and releasing water voles, but rapidly realised that successful re-introductions depended on being able to release the animals into the right ecosystem. The animals didn’t just need food, they needed habitat, prey, peers and even predators to establish themselves in the land.

Beavers caught Gow’s eye because, by damming watercourses, they create exactly the conditions that support water voles; wetlands rich in insect and invertebrate life. Today, Gow has around 15 beavers on his Coombeshead Farm in Devon and has been involved in multiple re-introductions around the UK.

The beavers dammed a stream that ran in a deep channel. In places, the dam was nearly 3 metres high. The resulting ponds and wetlands provide a safe habitat for the beavers and many other animals and plants. This is exactly the biodiversity that is so lacking in many parts of the British countryside. Decades of intensive farming, hedgerow removal, road-building and thoughtless development have removed critical parts of functional ecosystems. Biodiversity, which is the very nature of life, needs space to form and grow. Beavers are nature’s engineers. They create the conditions for life.