Fancy a drop of "kiwi-friendly" wine or a bite of a "kiwi-friendly" kiwifruit?
Branding fruit as "kiwi-friendly" could be a future marketing tool for producers after a study showed the North Island brown kiwi foraging for bugs in Northland vineyards and orchards, scientists say.
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The study is a collaboration between Massey University and the Bioeconomy Science Institute (BSI).
The brown kiwi increasingly observed in orchards and vineyards and New Zealand's goal of a predator free environment by 2050 prompted the research, according to BSI scientist Karen Mason.
"With Predator Free 2050, more of our taonga species will be moving into horticultural settings, so we wanted to look at, is that happening? And if it is happening, what are they doing? And are they providing any ecosystem services that will benefit the growers?"
Isabel Castro and Karen Mason Photo: RNZ/Sally Round
Masters student Wei (Xosha) Gong spent a year conducting field work on four sites in Northland, using camera and acoustic recorders, insect traps and faecal analysis to build a picture of kiwi behaviour, diet and predator presence.
From some 14,000 videos and 1000 audio recordings, and analysis of the bird's poo, the team were able to gain new insights into the kiwi's behaviour and diet in horticultural landscapes.
"We did get footage of them actually eating in the orchards, both probing into the ground and taking insects from just above the ground in the ground cover," Mason told Country Life.
Wei (Xosha) Gong, Masters student involved in the kiwi study Photo: Supplied/Massey University & Biosecurity Science Institute
Further research has shown the kiwi, with its long probing beak, were eating a variety of invertebrates including horticultural pests.
"They are consuming some very interesting ones, and where I think they can be really beneficial.
"We found that they were consuming a variety of different cicadas, the whitefringed weevil and grass grub, and all of those species spend time underground."
Apart from marketing their fruit as "kiwi-friendly", growers might also be able to reduce pesticide use if more kiwi were encouraged into orchards, Mason said.
"If an insect is subterranean ... it's quite difficult to control because they're difficult to monitor, they're difficult to locate.
"If you put sprays and chemicals down, the soil can bind some of those chemicals so it doesn't reach the insects and a couple of these insects also have a hard casing on them, so again, that makes it harder for the chemicals to reach them.
"Also, you don't want to broadcast a whole tonne of spray onto your soil and kill all your beneficial insects, like your worms. So I think that's where kiwi could be very interesting and very beneficial, because they are eating these when they are subterranean, when they're underground."
One of the "camera traps" used to record kiwi activity in a Northland orchard Photo: Supplied/Massey University & Biosecurity Science Institute
She said one pastoral farmer no longer needed to spray or to put granules down for his grass grub now that he has a high density of kiwi nearby.
Farmers and growers could encourage more kiwi onto their land by enhancing the orchard habitat and better predator control, according to Massey's Professor in wildlife biology Isabel Castro.
She said the brown kiwi, now numbering around 26,000, lived in a variety of settings.
"They can go into grassy areas, they absolutely love swamps, they also, of course, go into forests, but not only mature forests, but also they use scrub, and they use even very, very low vegetation, so they have no problems going into orchard areas.
"In saying that, most of the kiwi that we have observed, especially in vineyards, are close to small areas, at least, of vegetation. So if, for example, farmers will have a vineyard area and then that area is surrounded by a hedge of other vegetation, the kiwi will love that better than having a completely open area."
A collection of bugs and kiwi faeces analysed in the study Photo: RNZ/Sally Round
Mason and Castro are excited about the prospect of farmers harnessing the habits of other birds like pīwakawaka which could eat insects in the canopy or tui whose feisty nature might scare off kākā from feasting on the orchard's fruit.
But more research is needed.
"More different sorts of birds are going to start coming into our horticultural systems. We need to understand, how do we make them attractive? How do we keep the birds safe, and how do we keep the birds out?" Mason said.
- Video reproduced with permission
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