Large carnivores are critical to the balance of an ecosystem. In Yellowstone National Park in the western US, grey wolves keep elk populations at a healthy level. This prevents vegetation from being overgrazed and leads to taller woody plants which allow other species, such as beavers, to flourish.
But habitat loss and persecution have eliminated many large carnivores from their historical environment. The Eurasian lynx could be found in the UK over a thousand years ago and wolves roamed the country until the mid-18th century.
