Birds, Sex and Beauty: The extraordinary implications of Charles Darwin's strangest ideaIn all animals, mating is a deal. But few creatures behave as if sex is a simple transaction. Many treat it with reverence, suspicion, angst and violence. In the case of the Black Grouse, the bird at the centre of Matt Ridleys investigation, the males dance and sing for hours a day, for several exhausting months, in an exhausting and sometimes deadly ritual called a lek. To prepare for the ordeal, they grow, preen and display fancy, twisted, bold