England released eight beavers onto a dying river, hoping they could rescue its collapsing ecosystem. Five years later, the results stunned everyone—but not in the way scientists predicted.
In 2014, the British government learned that wild beavers had been living and breeding on the River Otter in Devon. Their origin was unknown. The government initially planned to remove them, but a wildlife charity successfully proposed monitoring them instead. Eight beavers were released back onto the river as part of a five-year experiment. The changes they brought to the water, wildlife, and sur…