The UK is one of the world’s most nature-depleted countries, but some of these creatures are starting to return.

Unofficial releases are widely believed to have caused some of the mysterious sightings on the River Tay in the east. A few years later beavers appeared in Devon on the River Otter and despite a government plan to remove these animals, they were allowed to remain. The species is protected in England and Scotland. However, landowners can still kill dozens of beavers each year.

The white-tailed Eagle is the largest predatory bird in the UK, with a wingspan of 2.5m. In 1780, the species was hunted into extinction. It wasn’t until Norway birds were used to reintroduce it to Scotland that the species was able to be reintroduced. In the last few years, official releases brought it back to England and the Isle of Wight, where this summer the first eagle hatchling in 240 years fledged.

Wild boars were absent from British countryside since the 13th century. It wasn’t until 1970s that a combination farm escapes and intentional releases allowed them to return. These omnivorous ecosystem builders, who use their large snouts for plowing up the soil, are now found in many parts of Britain, from the Forest of Dean and the Highlands of Scotland.

In June, more than a dozen butterflies that had been extinct in Britain since 100 years appeared in a nature preserve in Croydon in south London. This was likely the result of a release that was illegal. This striking black-and-white specimen is just the latest butterfly that has attracted the attention of maverick breeding enthusiasts, who have also spread endangered Glanville Fritillaries and marsh fritillaries around the country.

These small furry rodents play a vital role in river ecosystems. They create habitat for other species, by burrowing into the banks and providing food. Voles are so popular with other animals that they have been called ‘nature’s chocolat biscuit’. Pollution and habitat destruction have also threatened their numbers for a long time, but official releases of voles have now brought them back to streams across the UK.

A few official releases have helped to boost the numbers of these elusive trees dwellers. They prefer the grey squirrel as a prey. Their populations have been growing in mid Wales, and Gloucestershire. They are threatened all over Britain. Guerrilla rewilders likely increased numbers by releasing the animals in other areas, including a wooded area in south-west London.