The UK will soon have wild bison for the first time in 6,000 years

In 2022, four bison will be released in Kent, marking the first time wild bison have roamed in the United Kingdom in six millennia. Similar programs in other European countries have been very successful.

Bison are a keystone species which beneficially alters a biome. Via The Guardian:

Bison kill selected trees by eating their bark or rubbing against them to remove their thick winter fur. This creates a feast of dead wood for insects, which provide food for birds. Tree felling also creates sunny clearings where native plants can thrive. The trust expects nightingales and turtle doves to be among the beneficiaries of the bison's "ecosystem engineering".

Experts expect the herd to grow naturally with one or two calves each season.

Image: Wikimedia