They make a loud deep booming or honking noise like a foghorn every 2 seconds or so for up to a minute. They then emerge from their trance-like state, look around and listen for any responses, only to resume booming again all through the night. These puffed up thoracic cavities, and the bowl they lie in, act as resonating chambers, amplifying the noise and sending it out into the surrounding hills and valleys. They may keep up this booming all night, every night for three to five months. On suitable nights they make sharper ‘chinging’ cries which probably help hens to home in on the males. Females are attracted for kilometres around and spend a long time choosing a mate from among the competing boomers.
