Ranguru/Chatham petrel returning home

Classified as Nationally Vulnerable, the species is largely confined to Hokorereoro/Rangatira Island, with small, translocated populations on  Rangihaute/Rangiauria/Pitt Island and Rēkohu/Wharekauri/Main Chathams.  

We’re intensifying our work alongside our partners, to expand the suitable, safe habitat on both Rangihaute/Rangiauria and Rēkohu/Wharekauri for Chatham petrel and other rare birds and fauna.  This will enable us to establish larger translocated populations on both islands – more readily able to be seen and enjoyed by Chatham Islanders.  

However, as this will take time (a medium-term goal) we are building a more resilient population by re-establishing, with partners, a breeding colony on Maung’Rē/Mangere Island.

This year marked the third of four planned translocations to return Ranguru/Chatham petrels to Maung’Rē/Mangere. Over a six-week period from mid-April to the end of May, a team of nine worked together to move 60 chicks from Hokorereoro/Rangatira Island to Maung’Rē /Mangere Island and care for them until they fledged.

The team included staff from both our district and national teams, external contractors, volunteers, and a representative from Hokotehi Moriori Trust (HMT).

The operation began with four days of preparation, with team members split between Hokorereoro/ Rangatira and Maung’Rē/ Mangere Islands. On Rangatira, staff monitored, measured, and selected suitable chicks for transfer. Meanwhile, teams on Maung’Rē/ Mangere prepared the receiving colonies at Douglas Basin and Hut Colony, ensuring burrows and infrastructure were ready for their new arrivals.

Before dawn on a late April day, the team collected the selected chicks from Hokorereoro/ Rangatira. Calm seas provided unusually favourable conditions for the crossing to Maung’Rē/ Mangere onboard Owenga Charters. Additional team members joined the operation to help transport, process, and settle the birds into their new burrows.

By the end of the day, all 60 chicks had been successfully transferred and safely housed within the two recipient colonies.

For the next five weeks, between three and five team members remained on Maung’Rē/ Mangere Island, feeding the chicks daily and closely monitoring their condition. This intensive care period ensured the birds continued to grow and develop until they were ready to make their first flight to sea.

The first chick fledged on 6 May, with departures continuing throughout the month. The final chick left its burrow and departed on 28 May, bringing another successful translocation season to a close.

Of the 60 chicks transferred this year, 58 successfully fledged. One chick was humanely euthanised after losing primary wing feathers, leaving it unable to fly. A second chick was preyed upon by a hawk after emerging from its burrow at the Douglas Basin colony.

Despite these losses, the overall results remain highly encouraging. Across the three years of the project, 163 of the 166 translocated chicks have successfully fledged and departed for sea—a remarkable achievement for a species recovery programme.

The true measure of success is still to come. Ranguru/Chatham petrels spend several years at sea before returning to land to breed. This coming summer may provide the first opportunity for some of the translocated birds to return to Maung’Rē/Mangere as breeding adults.

If they do, it will represent far more than a successful translocation. It will signal the return of a species to one of its former homes and help restore the natural sounds of Ranguru/ Chatham petrels echoing across Maung’Rē/ Mangere Island once again.