Terry Reardon
Microbats cannot be seen or heard at night, but the tiny native mammal could become a new weapon in protecting grape crops.
Key points:
Microbats can eat up to 1,000 insects a night.
About 12 wineries in McLaren Vale have microbat roosting boxes.
They are as native to Australia as kangaroos and koalas.
Wineries throughout the McLaren Vale region, south of Adelaide, have thrown their support behind a project to find out whether the bats — which can weigh as little as 3 grams — could naturally protect grapes from hungry insects.
Ecologist Elisa Sparrow, who works for the Adelaide Hills and Mount Lofty Natural Resources Management Board (NRM) in the Willunga Basin, was one of the creators of the project.
She said the project, called Wildlife4Wine, was about supporting South Australian grape growers in "balancing wildlife, soil health and the practice of viticulture".
"Microbats provide an ecosystem service — they eat insects," she said.
"They can eat half their body weight in insects a night so they're pretty good at munching down on those insects and certain insects can be a problem in the vineyards so that's what we're planning to look at."
She said 12 wineries had installed roosting boxes on the fringe of their vineyards to see if any of the mammals were living in the area.
They are also using acoustic recording technology — which picks up the echolocation calls of the bats — to determine if any microbats were flying around.
"At the moment, we're just looking at what microbats will be around and then eventually we'd like to see what microbats eat — so to see if they eat some of those insects that cause damage to the grapes," Dr Sparrow said.
"It's really early stages of the project, we don't know a lot about what microbat species are in McLaren Vale so this is the start phase where we [are] trying to learn what is here."
Rescue bats shown to growers as part of program
On Tuesday night, the NRM ran a fully-booked workshop at Wirra Wirra winery to a group of McLaren Vale grape growers, viticulturalists and winery owners to explain how microbats could benefit the area.
The group was introduced to Barbie and Lily — two rescue microbats which have been living in captivity with carer Carmen Boehnle.
She said the two bats had very different personalities.
"Barbie is the oldest one and she's been in captivity for about nine years now — she's very shy. Lily is the outgoing one," she said.
"When I'm ready to feed them, Lily can hear me and all the noise in the background and all of a sudden, her head will pop out from under a log and she's ready to eat … and she's ravenous.
"She will eat one after the other, as fast as she possibly can.
"Whereas Barbie is, 'hmm not sure if I like that one, maybe another one'. They love mealworms and they like the juicy part of the mealworm at the end."
Ms Boehnle said Barbie and Lily had their "squabbles" every now and then but they tended to sort it out quite quickly.
"Barbie can never be released because they have what is called a scoop and as they fly along, they'll catch all the mosquitoes and insects underneath their wing, and she has a hole in that," she said.
"Lily came into captivity but they bonded very well so they've formed a nice partnership now and they'll be together for life."
Ms Boehnle said she inherited the bats from Adelaide Bat Care founder Mary Crichton, who passed away in November, so their history was a bit of a mystery.
She said microbats — which can live to 20 years — could hold an important place for the biodiversity of vineyards.
"They'll eat 1,000 insects a night, which is phenomenal for a little animal which weighs 15 grams, so I think it's fantastic that people, especially the wine owners, are listening to all of this and doing something about it," she said.
Bat expert Terry Reardon said there were about eight species of microbats in the Adelaide region.
They range in size with the smallest species having a wing span the size of a little finger.
However, he said it meant they had different dietary requirements.
"Often the larger bats will chase larger insects, like flying beetles and the tiny little bats will be chasing things like mosquitoes," he said.
"There has been very little research done in Australia about the relationship between vineyard pests and bats.
"But there has been some interesting developments both in the US and Europe where they're putting up bat boxes to attract bats to come to vineyards … and they're finding that they actually feed on some of the key pest insects of vineyards so we're hoping that's what we'll find here.
"What we're really keen on is building what we call bat hotels or bat condominiums, so we're now upscaling from these shoe-size boxes up to really large structures because some of the bats that typically go into the smaller boxes aren't the ones necessarily feeding on the moths out in the vineyards."
He said the hope was to attract the Chocolate Wattled Bat, which is a "moth specialist".
"I think that would be very good for orchards and perhaps for vineyards as well," he said.
Microbats are as native as kangaroos
Mr Reardon said bats were actually as native to Australia as kangaroos and koalas, but most people didn't think of them as being a native animal.
"I think most people don't really understand what bats are — we have over 80 species of bats in Australia," he said.
"They're specialised because they're the only mammals capable of sustained flight with echolocation.
"They have amazing wings, they're incredibly manoeuvrable."
He said microbats use echolocation — emitting call outs and listening to echoes or vibrations off objects near them — to avoid obstacles at night and to find insects.
Wirra Wirra winery viticulturalist Anton Groffen said he backed the project even before he knew much about it.
"The way we look after our vineyards, we're involved with sustainable winemaking programs and organic certification and we have an interest in increasing and managing our biodiversity on site," he said.
"So when Elisa from the NRM approached us about this project, we were all in without knowing anything about it.
"We're learning along the way, we don't know a hell of a lot about bats, but this project is about everyone learning a little bit more about bats and what the benefits are around vineyards."
He said the winery strived to have the smallest footprint possible, so if a native mammal could become a natural pesticide, allowing them to "knock another spray out", then it would be a big win.
"It's really surprising we're finding these bats and seeing them on the recorders because people are like, 'what do you mean we've got bats around here' because you can't see them, you can't hear them," he said.
"It's been a big surprise to us that we're living amongst them."
sm done 08032019 https://www.facebook.com/batsruleinfoonbats/
ReplyDeletepinterest