Every year, young black petrels disappear across the Pacific. Fewer than 10% ever return. This project is trying to understand why.
47 young black petrels are heading across the Pacific, and for the first time, we can follow them
By Live Ocean
20 May '26
Read time: 3 min
Article Summary
Main Points
From Aotea to Ecuador, researchers are tracking the first migration of 47 young black petrels across the Pacific Flyway.
The largest black petrel tracking study ever undertaken is helping uncover what happens to fledglings after they leave Aotearoa.
Over the past few months, many of you followed Jono’s Swim4TheOcean mission dot-by-dot down the East coast of Aotearoa New Zealand.
Now, there are 47 new voyagers to keep an eye on.
This week, 47 young tākoketai black petrels took flight across the Pacific Ocean for the very first time, leaving their burrows on Aotea Great Barrier Island and Te Hauturu-o-Toi Little Barrier Island and beginning an 11,000 kilometre journey towards the waters off Ecuador.
And this year, for the first time at this scale, we can follow them.
In the largest black petrel tracking study ever undertaken, fledglings have been fitted with satellite trackers to help researchers better understand one of the ocean’s enduring mysteries:
Why do fewer than 10% of black petrel chicks ever return home?
Understanding these ocean voyagers
Once widespread across the country, they are now found breeding in just two locations – Aotea Great Barrier Island and Te Hauturu-o-Toi Little Barrier Island. There are fewer than 5,000 breeding pairs remaining.
Despite spending most of their lives far out at sea, these birds return year after year to the same forested ridgelines where they hatched.
“They come back to their forests. They’ve lived here for generations,” says Wildlife Management International researcher Biz Bell, who has spent the past 31 years studying black petrels on Aotea.
Every year, black petrel chicks leave Aotearoa alone, navigating the vast ocean across the Pacific Flyway before reaching South American waters.
But what happens next has remained largely unknown.
“We’ve banded over 6,000 chicks over our 30 years, but unfortunately less than 600 individuals have been recorded back at the colony,” says Biz.
“We’ve only got a 10% recruitment rate – and we should have much higher than that.”
What threats do the black petrels face?
This tracking project is designed to help fill the critical knowledge gap. Researchers hope the data will reveal where fledglings travel, how they behave at sea, and what threats they face during these vulnerable early years of life.
“So we can see where they go and what risks they face overseas,” says Biz.The birds face mounting pressures both on land and at sea – including fisheries bycatch, climate change, introduced predators, plastic pollution and light pollution.
Light pollution has emerged as a growing issue for fledgling seabirds in northern New Zealand, with many young birds becoming disoriented by bright city lights during their first flights to sea.
Climate change is also beginning to reshape breeding success on Aotea, with storms like Cyclone Gabrielle having devastating impacts – 30% of the eggs and chicks were lost in a 24-hour period.
“The ultimate goal is to chart a course for recovery and protection of this on the brink species, so that we might see their return to some former nesting sites right around the North Island,” says Biz.
A lifetime at sea
Black petrels are remarkable ocean navigators.
They pair for life, share parenting duties equally, and somehow return to the exact same burrow year after year, often within metres of where they hatched.
“They migrate to South American waters 11,500 kilometres away, feed for a few months, get really fat and come back and do it all again,” says Biz.
“We don’t know how they do that.”
The fledging process itself is extraordinary.
For weeks before departure, chicks emerge from their burrows at night, flapping their wings to build strength before taking what researchers call their “first leap of faith” off the mountain.
“Sometimes they’ll make it and be on the wing and off they go,” says Biz.
“Other times they’ll crash land and have to do it all over again.”
Protecting a taonga species
This project is about more than tracking birds.
It’s about understanding how we better protect a taonga species and recognising the ocean connections that tie Aotearoa to the wider Pacific.
The project is guided by Ngāti Rehua Ngātiwai ki Aotea and Ngāti Manuhiri as kaitiaki of the tākoketai, and brings together researchers, conservation groups, councils, fishers and international collaborators across the Pacific Flyway.
Thank you to the BNZ Foundation, the Lou and Iris Fisher Charitable Trust, the Black Foils and everyone who supported our 2025 Christmas fundraising campaign to help fund these trackers and bring this research to life.
Thank you also to the Department of Conservation, the Conservation Services Programme and Auckland Council, for the ongoing support of the Wildlife Management International research team which has made this work possible.
Over the coming months, each signal from these fledglings will help piece together a story we’ve never fully been able to see before.
A story that could help shape the future of black petrels for generations to come.
