Only the hardiest of beasts survive in Britain's mountains and uplands, including the golden eagle and its prey the mountain hare, plus 400,000 red deer and flamboyant black grouse.
Britain's forests contain majestic trees, some of them thousands of years old. Behind the leafy veil, there are booming populations of previously rare wild boar and goshawks.
With more than 6,000 rivers criss-crossing our land, their denizens often go unnoticed. Solid bones and high oxygen levels mean a dipper bird can dive underwater for 30 seconds.
Evidence of how the countryside has changed more in the last 100 years than in the previous two thousand. Barn owls fight for their territory against kestrels.
On North Ronaldsay, one rare breed of sheep can subsist on a diet of only seaweed. In the Shetlands, otters benefit from a current of warm water flowing up from Spain.
