Madagascar

Using their necks like a long lever, males will battle other males over a female. But rather than simply engaging in neck-to-neck combat, males will perform elaborate dances, involving the swaying of their necks. The female acts like a referee, closely observing the fight. If she approves of the winner, she’ll allow him to mate.

Ever since people in tropical regions around the world began to grow Madagascar periwinkle (Catharanthus roseus) for its cheerful pink flowers, the plant…