Jungles and rainforests are home to 80 per cent of all species on earth, but they cover just 2 per cent of our planet's surface. To win the mating game here, you need to be able to stand out from the crowd. For some it's all about putting on a show, whereas others must fight for their chance of victory. And for a few creatures, working together is the key. Chimpanzees are notorious for their brutality and violence, and for most this is the simplest way to secure a mate.