Wingbeats returning to the mountain that roars

This past summer the wingbeats and calls of adult tītī (Cook’s petrel) and kōrure (mottled petrel) filled the night air at Maungaharuru – ‘mountain that rumbles and roars’ – as they returned to New Zealand’s most inland seabird translocation site.

Although the maunga is 30km inland, it’s not far as the petrel flies and historic evidence shows the area was once filled with seabirds’ burrows. While today’s sound of a handful of manu/birds returning is still far from the roar of the past, it’s a huge cultural and ecological step up from comparative silence.

Between 2013 and 2018 Poutiri Ao ō Tāne, a collaborative landscape scale restoration project, attempted to reintroduce petrels back into the ranges. Predation is one of the main reasons Maungaharuru went quiet, so it has required huge predator control efforts, including a two-hectare predator proof enclosure and traplines monitored regularly by DOC, Hawke’s Bay Regional Council and volunteer and community groups.

You can read more about the 2018 kōrure translocations here. Chicks live the first part of their life knowing only the inside of their underground nest. When they first emerge, they imprint on the location and consider it home. On fledging, juveniles head off on their OE for a few years but, when they start to think about settling down, they head back to the site where they first emerged.

We’ve been monitoring Maungaharuru since 2016 for returning manu using a range of methods. Most simple is the good old burrow fence method – placing sticks loosely across the entrance of the burrow, tell-tale signs of disturbance showing when birds have moved in. More high-tech are motion activated cameras around the burrows. We also do some in-person night monitoring at the site and play petrel calls during peak seasons to make it sound like petrel party central.

In November 2017 we were rewarded with the first signs of a returning tītī, shortly followed by a meeting in person early on Waitangi Day morning. This was marked with celebrations and the bird name ‘Waitangi’ was approved by Maungaharuru Tangitū Trust Kaumātua Trevor Taurima. 

Bird numbers and site activity have continued to slowly but surely rise. We’ve clearly identified a couple of individuals on our monitoring cameras. In December 2018, Waitangi brought home a friend and started to set up house, and this year he’s made a reappearance, although sadly his partner didn’t join him. The second tītī was named ‘Haruru’ (meaning ‘roar’ or ‘rumble’) by Trevor, anticipating the sound that the hills might make again. Haruru was first spotted in February 2019.

Although we’re yet to meet any returning kōrure in person, the first one was sighted on camera in January 2018.

This year, one of our rangers reported lying beside his truck under the stars, seeing silhouettes of the manu circling overhead and calling in the dusk, a truly magical moment. You can hear this and some of the camera footage on a Poutiri Ao ō Tāne video here.

Although the numbers of petrels returning seem small, it’s a strong indication they might start to breed in the next season or two. On the night monitoring sessions in December 2019 and January 2020, we heard and saw 10-15 birds circling above the bush canopy where the burrows are.

Tītī have started to reappear at the site from September and kōrure from around December. So far they seem to have all departed by March. When breeding starts, we expect the petrels to be around for longer as they feed their growing chicks.

This coming season, that’s exactly what we’re hoping to see. Waitangi and Haruru, our mystery kōrure, and all the yet-unnamed petrels will need to entice a partner to share their burrows and start a family.

We’ll be out there in September, doing basic maintenance to ready the site for returning residents, making sure the cameras are ready to go, and crossing our fingers under the night sky.

May the maunga roar again soon.

This project is part of Poutiri Ao ō Tāne, a collaborative landscape-scale ecological and social restoration project on the Maungaharuru Range, 60 kilometres north of Napier. It is a collaboration between DOC, HBRC, Maungaharuru Tangitū, Ngāti Pahauwera, Ngāti Hineuru, landowners, Manaaki Whenua-Landcare Research and the Aotearoa Foundation. Poutiri Ao ō Tāne has grown even bigger over the years and been brought under the umbrella of Predator Free Hawke’s Bay, which was formed last year. You can find out more on the PFHB website. https://www.pfhb.nz/