Kakapo don't breed every year - that depends on whether there's enough rimu fruit around for them to eat. But when they do breed, they do it different to most! Find out about the kakapo's unique courtship!
The kakapo 'boom' and 'ching'
In the breeding season, the male kakapo can inflate like a balloon and emit a low 'sonic' boom which, in mountainous terrain, can be heard up to five kilometres away.
Listen to the kakapo 'boom'.
Breeding activity usually starts in about December, when male kakapo take to prominent ridges, rocks or hilltops with low-growing vegetation and begin a courtship competition for female attention. This is known as 'lek' breeding, and is not known from any other parrot species in the world - or from any other New Zealand bird.
From its prominent bowl site, each bird inflates a thoracic air sac and emits a deep resonant non-directional 'boom' from its swollen body, announcing to any females in the area that he is ready to mate After 20-30 booms they then make a high-pitched metallic call, or 'ching'.
Listen to the kakapo 'ching'.
This pinpoints the male’s position, to direct the females to him. The booming and chinging serenade will last for eight hours without break, every night for 2-3 months in the breeding seasons when nesting occurs.
The males compete against each other, and can release thousands of 'booms' a night.
Each bird also forms a network of tracks radiating from a bowl-like depression in the earth, from which it is based. This is known as a 'track and bowl' system, which is also unique among parrot species of the world.
The female kakapo lays between one and four eggs, which hatch after about 30 days. As a solo parent, the female has to leave the nest at night in search of food, leaving the eggs or chicks alone. The chicks will typically fledge, or leave the nest, after about ten weeks. However, the mother may keep feeding the chicks for up to six months.
"(The kakapo boom) was like a heartbeat: a deep powerful throb that echoed through the dark ravines. It was so deep that some people will tell you that they felt it stirring in their gut before they could discern the actual sound, a sort of wump, a heavy wobble of air." - Douglas Adams, British author, 1990.