In recent decades, Britain has seen the reintroductions and translocations of many animals, from red kites and great bustards to pine martens and natterjack toads. But the pioneering Scottish Beaver Trial has been, if anything, even more significant than any of those. It was the first time a licensed, government-sanctioned project returned an extinct mammal to the wild in the UK.
Beavers are some of the greatest construction workers in the mammalian world. They are dam-builders, lumberjacks, engineers, architects and transport planners all rolled into one. They have, perhaps, a bigger deliberate impact on their surroundings than any other animal besides humans, and they can easily reconfigure their environment to suit their needs.