https://www.rspb.org.uk/our-work/policy-insight/species/beaver-reintroduction-in-the-uk/

>The Eurasian beaver is native to Britain and used to be widespread in England, Wales and Scotland, but was never known from Ireland.

>They became extinct in the 16th century, mainly because of hunting for their fur, meat and 'castoreum', a secretion used in perfumes, food and medicine.

>In Scotland, there are currently two populations of beavers. In Argyll, where the successful Scottish Beaver Trial ran from 2009-2014, a small population continues with help from some further licenced releases. In the east of Scotland there is an expanding population of beavers, from unauthorised escapes or releases from captivity, which currently inhabits the Tay and Forth catchments.