There were about 7000 myna birds on the island when the Natural Heritage Trust (NHT) launched an eradication programme back in May 2009.
Since then, a massive collective effort has whittled the bird’s population down to its last few hundred.
NHT director Gerald McCormack estimates there are only about 60 adults and 150 juveniles remaining on the island.
“I am confident that Atiu will be myna-free by mid-year,” he said.
Myna birds are considered a pest because they frequently ruin fruit on trees and even venture inside people’s homes to peck at uncovered food.
They are also territorial, known for harassing other birds and interfering with their nests.
Culling the birds has had a huge impact on the island, said McCormack.
Not only can locals now leave their food out but native birds - such as the kukupa (fruit dove), ngotare (chattering kingfisher) and reintroduced rimatara lorikeet - are now far more visible and vocal, he said.
“If you see movement in the trees now when you’re wandering around the island, it’ll probably be a native bird. Before, every time you looked it was a myna bird.”
Although the reduction programme began in 2009, it was ramped up in November 2010 when the island council approved the use of dedicated, imported shooters.
McCormack said efforts to wipe the bird out had stalled by late 2012, when the population seemed to plateau at about 1200.
“It just levelled off and we couldn’t seem to break it. I could see we were just never going to eradicate the bird.”
Using new four-door traps designed by McCormack, a trapper called George Mateariki has added more firepower to the programme.
“He catches 100 to 200 a month,” McCormack said.
The bird is currently in the middle of its breeding season but McCormack said shooter Jason Tuara is skilled at killing whole families of birds at a time.
“He’ll wait and wait until he shoots one of the adults and then waits for the other adult to come back and then he shoots that one, then shoots the young as well.”
Culling the mynas has had only one negative consequence – an outbreak of coconut stick-insects on the island, which damage coconut palms.
The main reason mynas were introduced to the Cook Islands in 1906 was to control the stick insect population.
The recent surge in stick insects on Atiu initially knocked the coconut palms but the trees are now bouncing back, McCormack said.
“The palms have shown a remarkable recovery,” he said.
Nevertheless, ongoing work is needed to reduce coconut stick-insect damage.
The Fiji Department of Agriculture recommends clearing weeds under palms so that the nymph insects are more likely eaten by chickens or trampled by livestock.
They also suggest smoky fires on still days can reduce the number of insects in palm crowns.
McCormack said the myna eradication programme has cost about $100,000, which has been provided by Conservation International.
Support has also come from Air Rarotonga, Atiu Villas, Snowbird Laundry and the Natural Heritage Trust.