The calls of kōkako are being heard in a remote Taranaki forest for the first time in more than 25 years.
Department of Conservation staff recorded the secretive bird at the Waitaanga Conservation Area after a surprise encounter at the remote forest in north-east Taranaki.
The recording has been analysed and its call is of a dialect from Pureora Forest in Waikato.
Five more birds have since been identified and all but one of them have leg bands, which were fitted for their translocation from Pureora to Parininihi in North Taranaki in 2018.
Biodiversity ranger Brandon Kingi, who has a key role in DoC's work in Waitaanga, said kōkako populations have distinct and identifiable local dialects in the calls.
"Kōkako have limited flight capabilities, and with Parininihi about 28 kilometres from Waitaanga, the birds have travelled an unusually long distance for the species."
The kōkako have also developed a new song to add to their Pureora call - raising questions about where the song came from, and its potential to be derived from original Taranaki birds that could be living in the area.
The team continued to survey Waitaanga for other kōkako in partnership with Tiaki Te Mauri O Parininihi Trust of Ngāti Tama.
Ground traps would be set up in the area where kōkako have been found to provide additional protection from rats, stoats and possums in between years when 1080 bait is aerially distributed throughout the forest.
Tiaki Te Mauri O Parininihi Trust operational partnerships manager Conrad O'Carroll said its team would help install the infrastructure and implement the plan.
"We also want to get our rangatahi involved as Waitaanga is a special place for us and we want to connect the people of Ngāti Tama back to the whenua."
Kingi said Waitaanga was a hotspot for native wildlife and the forest was in a healthy condition thanks to sustained control of introduced pests and predators.
"Without sustained predator control taonga such as kōkako would not have a safe habitat in which to thrive."
O'Carroll said for Ngāti Tama, the discovery of kōkako at Waitaanga was connected to the story of Tamanui - the last known kōkako of Taranaki.
"In 1999, Tamanui was moved from the Moki Forest in North Taranaki to Tiritiri Matangi Island, a sanctuary in the Hauraki Gulf that provided a safe haven for Tamanui and other kōkako to breed, with the understanding that his progeny would be returned once the damaged eco-system was restored."
Descendants of Tamanui were successfully returned to Taranaki in 2017, through a translocation from the island.
There were now about 10 breeding pairs at Parininihi and some single birds.
Kingi said many other rare native species at Waitaanga and Parininihi were benefiting from predator control including kākā, kiwi, pekapeka/bats, whio and dactylanthus/ te pua o te rēinga.
"I encourage people to visit these forests and experience the beauty for themselves."
Kōkako fast facts
Predation at nests - mainly by ship rats and possums, and occasionally stoats - is the primary cause of decline for North Island kōkako. Female kōkako are particularly at risk of predation as they do all the incubation and brooding throughout a 50-day nesting period. Years of predation have resulted in populations that are predominantly male and with consequent low productivity rates.
Pest control - the huge effort across the North Island by many groups to control introduced pests and predators and restore native forest habitat is making a difference. From a population of just 300 breeding pairs in the late 1990s, the North Island kōkako now boasts more than 2000 pairs.
Famous call - Kōkako are part of the ancient wattlebird family and are cousins of the extinct huia and the endangered tieke (saddleback). They are famous for their haunting call, like ringing bells. Their song carries for a great distance and is heard mostly at dawn when birds call to maintain their territories. Pairs may duet for up to half an hour with other kōkako joining in too.