Critically endangered long-tailed bats roosting in Waipawa

The little creatures weigh less than 20g, and easily fit in the palm of your hand. Photo / RNZ / Lauren Crimp

By Lauren Crimp of RNZ

A colony of long-tailed bats has been found roosting in an unlikely spot: a farm shed roof in Central Hawke’s Bay.

One conservationist is calling the district “bat central”.

Infamous for taking out the Bird of the Year competition in 2021, the long-tailed bat is critically endangered - and bats are Aotearoa’s only native land mammals.

They usually lived in areas with pristine native habitat and predator control, so it was unusual to find such widespread activity in a fragmented, agricultural landscape, Conservation Company co-founder and bat ecologist Kay Griffiths said.

“We’re sort of calling it ‘bat central’ because we’ve got quite a lot of activity in lots of places, and they’re probably roosting in all sorts of places, and there’s probably lots of small colonies,” she said.

The long-tailed bats are roosting in the rafters. Photo / Lauren Crimp / RNZ

Landowner Nick Perry first made the discovery in his Waipawa shed while out feeding the cows a couple of years ago.

“Just walking around with the nieces and standing in front of the shed here, and they started flying out over our heads.

“We didn’t know what they were, we thought that they were maybe swallows or something like that.”

Or, “fuzzy black things”, as described by 9-year-old niece Evelyn Perry.

Processing the bats is a team effort, run by bat ecologists and supported by local volunteers. Photo / Lauren Crimp / RNZ

There was little known about the colonies in the area, so the Department of Conservation and Lotteries were funding the Conservation Company’s research.

While an easily accessible shed made the bats easier to follow, Griffiths said it was concerning to find pekapeka-tou-roa/long-tailed bats holed up in the rafters.

Bats usually shifted roosts nearly every morning, probably to avoid predators.

But this group kept coming back to the same spot.

“That kind of tells us that probably all their roosts that they know of around here, are gone.”

Nick Perry (left) with Kay Griffiths and Craig Single of the Conservation Company. Photo / Lauren Crimp / RNZ

Those roosts - big exotic trees - were being chopped down to make room for development, she said.

But the bats would soon begin searching for new spots once breeding season was over, so the team wanted to find out where those were, and ensure they were protected.

That involved trapping and banding the shed-dwelling bats.

So on a balmy summer evening, Griffiths, her partner and Conservation Company co-founder Craig Single, and a group of locals - some scientists, and some who were just fascinated by the little creatures - swatted away mosquitoes and waited for darkness to hear their unmistakable squeaks.

Kay Griffiths and Craig Single set up the harp traps. Photo / Lauren Crimp / RNZ

About 9pm they could be heard, and then, those that managed to escape the traps were spotted, flitting about the nearby trees.

Previous nights spent counting the bats swooping out of the shed revealed there were about 45 in the roost.

But just over 20 were caught in the harp traps, a series of tall fences with two vertical rows of fishing nylon, slightly offset so most bats would get through one, but be stopped by the next.

After recording their weight, size, sex, and age - juvenile or adult - they were released.

The bats are measured and weighed, and their age and sex are recorded before they're released. Photo / Lauren Crimp / RNZ

One was even named ‘Cupcake’ by Evelyn.

The Conservation Company would be catching up with Cupcake and its colony in March - hopefully near new roosts - to learn more about them, and help ensure their survival.