‘Weird’ kiwi nesting behaviour noticed

Conservationists working in the Maungataniwha Native Forest, near Wairoa, say “weird” kiwi nesting behaviour in the summer of 2022/2023 is repeating this year.

There was an unusually high number of third clutch eggs last year, while this year there is significant overlap between first and second clutches, a media statement from the Forest Lifeforce Restoration Trust said.

Kiwi normally produce eggs in two distinct clutches, typically towards the end of spring and then again in late summer or early autumn. The second clutch of the 2022/2023 season was noticeably late. In another unusual development, three of the trust’s monitored kiwi had three clutches.

This season some of the trust’s monitored kiwi have started laying their second clutch of eggs unusually early, even before others had laid their first clutch.

“There hasn’t been the usual distinct break between first and second clutches, and some birds have skipped their first clutch altogether,” said trust kiwi expert Tamsin Ward-Smith.

“It will be interesting to see if we get some birds going on to have a third clutch this season, and if they are the same birds as last season or different ones.

“We’re not sure what’s behind this weird nesting behaviour so we’re putting it out there for the wider kiwi conservation community to consider.”

At the end of the 2022/2023 egg-laying season earlier this year, Ms Ward-Smith said she suspected the unusual egg-laying patterns  were due to Cyclone Gabrielle and the generally wetter than normal summer producing an abundance of invertebrate life, resulting in fit and feisty kiwi ready to produce a good number of eggs.

The Forest Lifeforce Restoration Trust sent 49 viable eggs to the National Kiwi Hatchery in Rotorua in the first half of the season, just six short of its first clutch record.

However, the trust is monitoring 11 male birds fewer than in previous years, so this year’s first clutch result is proportionally greater than recent years.

The egg-lifting work is part of Operation Nest Egg, the nationwide kiwi recovery initiative that removes kiwi eggs from their burrows, incubates them and cares for the chicks in captivity until they’re big enough to fend for themselves in the wild.

The Forest Lifeforce Restoration Trust was established in 2006 to provide direction and funding for the restoration of threatened species of fauna and flora, and to restore the ngahere mauri (forest lifeforce) in native forests within the Central North Island.

In addition to the Maungataniwha Kiwi Project the trust runs a series of native flora and fauna regeneration projects. These include a drive to increase the wild-grown population of kakabeak (Clianthus maximus), an extremely rare type of shrub, and the re-establishment of native plants and forest on 4000 hectares currently, or until recently, under pine.