Bigger haul of seabirds in effort for first re-established colony on South Island’s mainland

Wednesday, 28 February 2024

92 more pakahā/fluttering shearwater chicks have been moved to an eco-sanctuary at the northernmost point of the South Island, to try to re-establish numbers of the endemic seabird there.

A third round of endemic seabird chicks have been moved to a predator-free spot at Cape Farewell, as efforts to create a colony of the birds there approach a crucial point.

HealthPost Nature Trust said 92 of the fluttering shearwater/pakahā chicks were moved to Wharariki Eco-sanctuary from Long Island/Kokomohua in the Marlborough Sounds on January 13, for the project aimed at creating a breeding colony of the burrow nesting birds at the site.

It brought the total number of chicks moved from Kokomohua to the clifftop sanctuary at the South Island’s northernmost point to 198, after two previous translocations in January 2022 and January 2023.

Some of the team that moved fluttering seawater chicks from Long Island/Kokomohua in the Marlborough Sounds, to Wharariki Eco-sanctuary at Cape Farewell in January 2024.

Whether it would be the final round of birds needed to create a colony along the rocky headland was expected to be known later this year, when the birds from the first round were due to return, trust spokesperson Nate Wilbourne said.

All the chicks in the first two translocations (50 chicks, followed by 56) had fledged their nests and flown away.

A team visits Long Island (Kokomohua) in the Marlborough Sounds to collect a group of fluttering shearwater chicks there, and relocate them to Wharariki Eco-sanctuary at Cape Farewell.

The birds migrated to Australian and subantarctic waters, and then flew back to their “source burrow” three or four years later to breed, Wilbourne said.

The chicks that had been relocated to burrows in the 3-hectare sanctuary near Farewell Spit were ones that hadn’t yet fledged from their burrows on Kokomohua, as birds tended to return to the place from which they fledged.

If a colony was established at the sanctuary, it would be the first time a pakahā population had been re-established on the mainland in New Zealand.

Pakahā/fluttering shearwater chicks are hoped to re-establish a colony on the mainland.

Colonies of pakahā were created on Mana Island off the west coast of Wellington, and Maud Island in the Marlborough Sounds, after chicks were moved there from Kokomohua between 2006-2008 and 1991-96 respectively, he said.

A colony was also established on Matiu Somes Island in Wellington Harbour.

The trust aimed to translocate 90 of the birds on this third round, but 60-70 was thought to be more likely, Wilborne said before this year’s effort.

A goal to relocate 100 of the birds to the sanctuary last year was hampered by slips on Kokomohua after heavy rain, so volunteers only took out 56.

But hot, dry conditions brought by the El Niño climate cycle seemed to have improved breeding conditions, with more chicks on Kokomohua, he said after the trip.

The project – a partnership between the trust, the Department of Conservation and local iwi body, Manawhenua ki Mohua – was a “crucial step” towards the ambitious goal of creating a safe haven for various native species at the site, Wilbourne said.

The area where the sanctuary was located would have been home to millions of fluttering shearwater, among other seabird species, long before introduced predators arrived with settlers, he said.

There were now only “a couple of remnant colonies” along the coastline, with about 20 burrows, Wilbourne said.

The trust wouldn’t know if a fourth round of birds needed to be moved to the sanctuary until October/November, “when we see how many birds have returned” and laid eggs, he said.

The sanctuary had a permit to take about another 50 of the birds, Wilbourne said.

There were 225 chicks were moved to Mana Island and 334 to Maud Island in those successful restoration efforts, he said.