During this time mammals, along with some large flightless birds, did take over.

ECONOMIST: Rewriting the history of the mammals

It has some of the highest cliffs in Europe, which have large colonies of rare and endangered species of birds.

UNESCO: World Heritage

The bigger problem: Despite being the cleanest energy available, some environmental groups object to large wind turbines spoiling the landscape, as well as the impact on migrating birds.

FORBES: Continental Divide