Kakapo the reason for its massive decline since the introduction of dogs, cats and mustelids (see "Conservation: Human impact"). 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. During
Glossary of bird terms this glossary does not contain individual entries on any of the approximately 9,700 recognized living individual bird species of the world. Glossary of bird terms The following is a glossary of common English language terms used in the description of birds—warm-blooded vertebrates of the class Aves, characterized by , the ability to in all but the approximately 60 extant species of flightless birds, toothless, , the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart and a strong yet lightweight skeleton. Among other details such as size, proportions and shape, terms defining bird features developed and are used