Kakapo are not having enough sex and the Department of Conservation aims to do something about it.
For the first time next breeding season the department will ensure every female kakapo at the kakapo refuge on Codfish Island near Stewart Island mates twice - even if that means artificial insemination.
"We’ll need animal ethics approval but apart from that I can’t see any reason why we shouldn’t do it," said DoC spokesman Paul Jansen.
"We need twice the fertility we’ve got now."
Scientists have discovered female kakapo that mate twice in a season have a higher chance of producing fertile eggs. That was thought to be because of the "very poor quality" of male kakapo sperm, Mr Jansen said.
"The majority of kakapo sperm is rubbish. Even productive birds have poor sperm because of past inbreeding," he said.
"They’re so inbred that if they were humans, they’d probably have six fingers and be playing a guitar."
Next month, the kakapo population of 87 is expected to hit 91, the highest of recent times after a population plunge to just 50 in 1995.
But fertility and embryo deaths are way too high, Mr Jansen said.
"We had 27 eggs this year. Only 40 per cent ended up hatching. That’s pretty bad," he said.
Females will be injected with male sperm if they have not already had two matings.
Kakapo chicks are also being removed from nests as this breeding season reaches its end.
At a month old, chicks will be taken from females and hand-reared.
Chick-rearing took a "heavy toll" on females, Mr Jansen said, and also meant they would not re-nest the following season. "Hopefully it will mean we’ll have 20-plus females ready to breed again this coming season because we’ve never had a female that has raised chicks in one season and then re-nested."
Birds at risk
New Zealand’s endangered bird species include:
Large flightless birds (kiwi, kakapo, takahe)
Wattlebirds (tieke, kokako)
The world’s only alpine parrot (kea), one of two torrent ducks worldwide (whio or blue duck) and a honeyeater (stitchbird).