Tītī returned; but will chicks survive predators?

Conservationists are relieved after this year’s migratory tītī/sooty shearwater finally returned to a colony on the Otago Peninsula.

The migratory seabirds were three weeks late returning to the colony, at the same time as other colonies reported fewer numbers returning from the northern hemisphere.

“Seabirds are the most threatened group of birds in the world,” says Francesca Cunninghame, Forest & Bird’s Otago Seabird Projects Manager. “While at sea, they face many challenges such as the impacts of commercial fishing, plastic pollution, and climate change.

"So when they were late returning, we were quite worried that they might not come back at all.”

Forest & Bird staff and volunteers are hopeful that this year’s returning tītī, also known as muttonbirds, will successfully fledge chicks at the site for the first time.

Forest & Bird has been working for the past two seasons to help tītī successfully breed at the regionally significant remnant colony at Sandymount. But no tītī chicks have survived, with one ferret killing all the remaining monitored chicks just a couple of weeks before they were due to fledge in April 2019.

You can see the images here.

Forest & Bird volunteer and contractor Graeme Loh was devastated when he discovered the predation of the six chicks.

“It was gruesome. Each burrow still had the body of a large plump fluffy chick, dead from injuries to the neck. After months of work, one ferret had got through the trapline and wiped out the entire colony. It was a massacre.”

Now Forest & Bird’s team of volunteers will shore up predator control on the clifftop site in a bid to stop ferrets and other predators (such as stoats, weasels, feral cats, rats, hedgehogs, and possums) killing the chicks over the coming spring and summer.

Forest & Bird’s Bring Back the Seabirds project in Otago is focussed on protecting remnant mainland breeding colonies of tītī, fairy prions, red-billed gulls, and white-fronted terns. Introduced predators have contributed to declining numbers of several seabird species, many of which are now restricted to breeding on predator-free offshore islands.

“Nowadays there are a few remnant mainland colonies, which are in desperate need of protection,” says Ms Cunninghame.

“Otago would once have supported several million breeding tītī/sooty shearwater and it would be great to see them return in large numbers. But to do this we must make the sites where they can breed free of predators, in addition to addressing the threats seabirds face at sea.

“We are securing funding to extend our predator control in the area and will also be using a conservation dog and cameras to help identify and monitor the burrows after the birds lay eggs in early December.”

Tītī spend most of their lives at sea, travelling to waters in the northern hemisphere during our winter. They return to southern New Zealand in late September and prepare to breed.

“Our predator control work is only focussed on a fraction of their life cycle, while they breed on the mainland. After they fledge, all we can do is wish tītī good luck and hope that, against all odds, they’ll someday return to Sandymount to have chicks of their own,” adds Ms Cunninghame.

Photos available:
• Graeme Loh with body of predated chick, showing injuries
• Actual wildlife camera pictures of ferret invading tītī burrow.

Note: This year there are fears for another species of shearwater, the short-tailed shearwater, which is late for breeding in Australia, after thousands were found dead in Alaska.

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