The world’s fattest species of parrot has had a record-breaking breeding season in New Zealand, with scientists saying the fortunes of the critically-endangered bird are finally turning around.
There are only 147 adult kākāpō alive today, although a few hundred years ago they were one of New Zealand’s most common birds, before being hunted to the brink of extinction, killed by introduced pests, and losing their forest homes to farming.
The nocturnal, flightless parrot is one of New Zealanders favourite birds, and is known for its charismatic nature and owl-like face.
Because the population is so small every kākāpō has a name – including Ruth, Hoki, Suzanne and Zephyr – and is subject to one of the most intensive management programmes of any species in the world. Infertility and in-breeding have been long-term issues for the birds’ reproductive efforts.
But this year 76 kākāpō chicks have hatched and 60 are expected to make it to adulthood, the result of heavy seeding in the New Zealand bush that has produced an abundance of the bird’s favourite food: fruit from the Rimu tree, a southern species of conifer.
Forty-nine out of 50 breeding females laid eggs this year. The last record-breaking breeding season was in 2016, when 37 chicks fledged.
“It’s absolutely huge, it’s massive,” said Dr Andrew Digby, a science advisor to the Department of Conservation’s kākāpō recovery programme.
“In the last two seasons there have been huge quantities of fruit not seen for 50 years, so that’s why all of the female kākāpō know it is time to breed, and actually started much earlier than usual, meaning some have now been able to nest twice.”
Digby says his team give kākāpō “no privacy” during the critical breeding season.
“I can be anywhere in the world and log in and find out which kākāpo mated last night, who they mated with, how long they mated for, the quality of the mating – its real big brother stuff,” he said.
Conservation efforts also include an international effort to sequence the genomes of every known living kakapo, artificial insemination techniques, and supplementary feeding trials to optimise productivity.
“We have to be intensive at the moment,” said Digby.
Every kākāpō in New Zealand has a smart transmitter attached to its body, and remote monitoring systems are embedded in their nests. Rangers also check chicks every night while they are growing, and there are currently seven chicks being hand-reared by DoC staff.
The chicks are being raised on two predator free islands off the coast of New Zealand, on protected sanctuaries that are pest-free, but eventually the kākāpō recovery team would like to reintroduce them to mainland New Zealand’s bush, cities and towns.
The population would have to get up to “at least 500” for the scientists to think about backing off, Digby says.
“When you’ve only got a population of 147 anything could wipe them out and they could become extinct quite quickly. We want to get 150 breeding females, and ideally some unmanaged populations, before we can start to relax a little bit.”
Kākāpō were once thought to be extinct until a population was found in the 1970s on Stewart Island, at the bottom of the country. They reached their lowest number in 1977 at just 18 known birds, and even by the mid-1990s the population had only reached 50.
“They’re a very unusual bird, they’re the world’s only flightless parrot, and they have been following their own evolutionary path for 30 million years. There is so much to learn from them – they are strange and unique,” said Digby.