Males of the Golden-collared Manakin (Manacus vitellinus) perform elaborate courtship displays that are among the most spectacular in the animal kingdom. During an extended breeding season, male manakins aggregate in leks, where each male clears a small court on the forest floor to perform his displays. These behaviours are driven by sexual selection, which is particularly intense in lekking species in which females choose their mate mainly on the basis of behavioural and morphological features. Over the last several years, we have studied the proximate and ultimate causes of the courtship behaviour of Golden-collared Manakins. We found that these behavioural specializations are accompanied by unique morphological and physiological adaptations involving muscular, neural, and hormonal systems. The control of courtship by androgens differs from that described in lekking species of temperate zones: manakins have elevated androgen levels at the beginning of the displaying season but low or variable levels for the following months, although displaying activity does not change. Detailed analyses of male courtship using high-speed videography show that the displays require amazing accuracy and neuromuscular coordination. Indeed, females mate preferentially with males who perform their displays at a faster pace while maintaining exquisite postural control. All together, these studies reveal evolutionary and physiological mechanisms that underlie the spectacular courtship displays of manakins.