Photos of the Bat Team in action: Asia Martusia King / Aotearoa Science Agency
Photos of the Bat Team in action: Asia Martusia King / Aotearoa Science Agency

ScienceDecember 10, 2023

We’re going on a bat hunt

Photos of the Bat Team in action: Asia Martusia King / Aotearoa Science Agency
Photos of the Bat Team in action: Asia Martusia King / Aotearoa Science Agency

In rural South Auckland, a team of conservationists head out on a nocturnal mission to track down Aotearoa’s only native land mammal. Asia Martusia King tags along.

The bat hunt begins as usual: with Vengaboys. A group of scientists sits sombrely around a table in a rural South Auckland paddock, as ‘We Like To Party’ plays beneath the stars.

It’s for good luck, explains Natasha Bansal, a research supervisor from EcoQuest. It’s a rite which emerged with bat surveys down south in Te Waipounamu, though nobody quite remembers its origins. Last night the team played Vengaboys twice and found six females.

I’m with a jumble of researchers seeking out pekapeka-tou-roa, or long-tailed bats. Bats are Aotearoa’s only native land mammal and they remain staunchly enigmatic. Pekapeka-tou-roa are choccy brown, the size of our thumb, and roost collectively in tree hollows, but we don’t know much else about their behaviour. Their ancestors buffeted to Aotearoa on ancient Tasman Sea winds two million years ago, roughly 20 million years after their short-tailed cousins had already settled and evolved. Now due to deforestation and introduced predators, their conservation status is listed as the highest ranking threat – Nationally Critical.

The bat team set out on their hunt (Photo: Asia Martusia King)

Natasha places a bat monitor on the table. It’s a walkie-talkie that tunes into bat frequencies otherwise unheard by human ears. They’re startlingly chatty creatures. A long-tailed bat will communicate at an ultrasonic frequency of 40k when feeding, and the impending darkness means it’s time to catch breakfast. Unlike their omnivorous short-tailed counterparts, which feed by snuffling along the forest floor, long-taileds are expert marksmen who snatch prey midair.

Sending out sonic clicks into the night, their echoes reveal the shape and location of tasty flying insects.

When a bat flies overhead, twittering away, the monitor crackles like a Geiger counter. Conversations halt as heads raise to the dusking sky.

“I think I just saw one go past,” somebody says, pointing to a minuscule Halloween silhouette above the totara. “It must be waking up and cruising for a feed.”

There’s something splendidly cowboy about sitting at camp, sharing soup and stories in the red glow of torches. Ruru hoot overhead, crickets bleat, and an asteroid smoulders across the sky, its tail flaring white-green.

Ben Paris, colloquially known as “the Batman”, is a senior conservation advisor at Auckland City Council. He yawns and readjusts in his foldout chair. “Long-tailed bats are a critically threatened species in a very fragmented landscape,” he explains. “We’re going to try to find out where they are and what they’re doing, to protect them.” This is the first bat research the team has done in rural Auckland.

What makes this project different is that it involves the iwi as well. Natasha has been training up Sky Flavell of Ngāti Te Ata, “an inspirational young kaitiaki” who loves doing the night work and is already “better at tracking bats than a lot of us”. Sky is in bed currently, getting some rest before taking over the 4.30am shift.

Natasha and Ben both say their work isn’t just about tracking bats, but also about empowering the community to keep it going after they’re gone. Natasha is especially excited to see young Māori like Sky get involved. “They can take that skill back to their iwi. It’s about upskilling them and giving them that power. Pekapeka means so much more to [tangata whenua] than we can understand as a taonga species, so it’s really special that they can be involved in it.”

Erecting the harp trap (Photo: Asia Martusia King)

Earlier that evening, harp traps had been assembled beside promising trees. The “harp” refers to the trap’s vertical strings, thin as cobwebs, which aren’t detected by a bat’s echolocation; a bat bumps into them and painlessly plops into a catch bag below. When a bat is caught, a tiny transmitter is glued to its head. The transmitter only weighs about 5% of the bat’s body weight but it does look extremely dumb.

Do the bats get ostracised for their silly hats?

“Probably. They do sulk,” Natasha says. A bat might throw a sook and hide for 20 minutes after getting tagged, but they get over it. Bats are social creatures and this is used to the team’s advantage. A lure is erected by the trap which transmits bat noises, enticing pekapeka to investigate. The sound sample is actually from a European bat but it still appears to do the trick, particularly with curious females. It’s the equivalent of hearing a sexy Italian exchange student.

When a bat is caught, it’ll be given a name for monitoring purposes, then stalked back to its roost for further research. Last night’s bats were named Ella, Caroline, and Fatty. Natasha is still waiting on a Batasha.

It becomes clear how little we know about our native bats. One team lead insists on using red-light head-torches to avoid bat detection; someone else says regular LEDs are fine. A scientist pleads for everybody to sit in silence, but another posits that our vocal frequencies don’t bother them.

What is certain is that monitoring bats is vital for teaching us about their habitat, behaviour, and the effectiveness of pest control in the area.

A red-light head torch illuminates the catch bag below the trap. (Photo: Asia Martusia King)

Andrew Sinclair of Whakaupoko Landcare and Predator Free Franklin supports the team by tracking down their roost trees during the day. He’s also been coordinating pest control in the area for 20 years – vital work to protect native birds and bats alike. “One of my neighbours’ cats brought a bat in once. We have other animals preying on them too, like stoats and possums.”

He’s seen the results of his work for himself: “The bat trend goes up with the increasing amount of pest control that we do.”

What amazes me is the public enthusiasm for protecting the bat. In a world where bats are widely associated with fear and disease, New Zealanders still dearly cherish our odd and mysterious wee mammal. Some clever PR has no doubt helped, including the controversial inclusion of the long-tailed bat as a finalist in the 2021 Bird of the Year – a contest it went on to win outright.

The media coverage of that year’s shock win has had a long tail (sorry) in terms of heightened awareness. These days blokey South Auckland farmers are delighted at the prospect of bat surveying on their land, and continue to monitor populations long after the scientists have packed up. Local schools and community groups contact bat hunters to get involved. I’m one of innumerous laypeople eager to protect our taonga.

“Science isn’t just for scientists,” says Natasha. “Anyone can do it.”

“You can’t be everywhere at once, so you’ve got to get the community involved to be your eyes and ears,” Ben adds. Thanks to community engagement, he says, this is likely the first part of South Auckland to have a solidly good level of sustained pest control. “That’s why the bats are flourishing here. I didn’t realise how much people wanted to have bat detectors on their land, or to catch bats. I’m blown away by the community here. It promotes that sense of guardianship in their own backyards.”

Bat hunting takes a lot of patience, and coffee. By the time midnight crawls around, I’ve seen plenty of cows and stick insects – but no bats. Sky Flavell will soon blearily wake and take over our shift. Vengaboys have failed us tonight.

A baby bat gets checked and tagged. (Photo: Aotearoa Science Agency)

The bat hunt ends for me, a sleepy journalist, but it’s only intermission for the other members of the team. Natasha, Ben, Andrew, Sky and countless others will continue to sacrifice sleep to learn more about our pekapeka; to guard them, to educate others, to pass on their skills.

I’m thrilled to later learn that 37 bats are caught in one roost – including one christened Batasha. They’re all females, meaning that it’s a maternity roost, a girl-boss creche of flying mammals.

“We have yet to catch any males yet but some females were pregnant, so we know they are hiding somewhere in the landscape in their mysterious bachelor roosts,” Ben tells me later, via email. “We’re getting some good information about [Batasha’s] movements over a hyper local area each night before they go back to the same location to roost.”

He signs off with a message to the community – a bat signal, if you will. “We’re really lucky to have had funding from the Franklin Local Board and the targeted rates… but we’d love a corporate partner to help continue this work.” With full funding, the team will be able to “find out how this rural population of pekapeka uses this fragmented landscape,” Ben says, “so we can better protect them into the future”.

Thanks to the Aotearoa Science Agency and the bat team for the opportunity to share awareness of our pekapeka. 

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