Known in zoological circles as leks, these events are essentially sage grouse discos; the battle for sex is played out using the medium of dance, with the males strutting about, providing their own unlikely soundtrack by, basically, beatboxing. Male greater sage grouse have a massively distended oesophagus which they can inflate by gulping down mouthfuls of air to create a large wobbly white-feathered throat balloon, which when fully swollen briefly exposes two bulbous patches of olive-green skin that pop forth from their feathers like a pair of nippleless shop-dummy breasts.
