 The kakapo is the only species of flightless parrot in the world , and the only flightless bird that has a lek breeding system . Males loosely gather in an arena and compete with each other to attract females . Females listen to the males as they display , or " lek " . They choose a mate based on the quality of his display ; they are not pursued by the males in any overt way . No pair bond is formed ; males and females meet only to mate . 
