The population of New Zealand's endangered flightless parrot kakapo has increased by 25 per cent in the past year, bringing it up to 252 birds.
The New Zealand Department of Conservation said that the increase in kakapos was due to a good breeding season and success with artificial insemination.
Introduced predators such as stoats have nearly wiped out the kakapo as the birds can't fly.
The problem has been exacerbated by inbreeding, very low fertility - only 50 per cent of eggs are fertilised - and because they only breed every two or three years when native rimu trees fruit.
The population of the kakapo, the world's heaviest parrot, is now at its highest number since the 1970s.
There were just 86 kakapo when I started working as a kakapo ranger in 2002, according to Deidre Vercoe, operational manager for the Kakapo recovery program.
That number was scary. It feels like a positive step when you have a breeding season with 55 chicks. The program was started in 1995. It is a collaboration between the New Zealand conservation department and Maori tribe Ngai Tahu and uses volunteers to help with activities like monitoring the nests to keep them out of trouble.
Several birds had to be rescued after getting stuck in the mud or after their legs were caught in trees.
Ms Vercoe said the fruit on rimu trees was the reason behind much of the success this season.
She said that this season was key to success with artificial insemination. In the decade to 2019, eight surviving chicks were born from artificial insemination, compared to just five in the decade to 2019.
Using artificial insemination has resulted in a number of males who had not yet naturally fathered chicks, still are represented in the future gene pool, Ms Vercoe said.
Artificial insemination can help to increase the fertility of the eggs laid.