To farmers, these tiny bats are worth a lot more than just their weight in pests

A citizen science project tracking insect-eating bats is uncovering just how vital the tiny creatures are to farmers in western New South Wales.

The bats consume their own body weight in insects like cockroaches, mosquitoes and agricultural pests every night.

Department of Planning and Environment threatened species officer Jess Peterie said the diet provided a valuable service for farmers.

“Insectivorous bats provide natural pest control services worth $63.3 million annually in avoided cotton yield damage to the Australian cotton industry, which is huge,” she said.

“So they’re really important within our ecosystems, but they have a huge benefit for our primary producers as well.”

Bat under threat

But insect-eating bats in NSW are declining in number.

There are 34 species of bat in the state and 18 are listed as threatened or are thought to be extinct.

The Bats in Backyards project, run by the Department of Planning and Environment, is now in its second monitoring season and is being expanded to include Nyngan, Munangdi and Weemalah.

“Our understanding of bats in these regions is more limited compared with the coastal regions,” Ms Peterie said.

“Bats are under threat from habitat loss, human activity through urban sprawl and climate change.”

As part of a five-night study, landholders in those areas will be equipped with bat detectors that will capture the high-frequency echolocation call from bats soaring overhead.

“Knowledge is power, so by learning about where they occur, what things in the landscape are important for them, landholders might be able to learn something,” Ms Peterie said.

Secret language

Unlike fruit bats, which are seen moving through pollinating plants and are known for their shrieking sound, insectivorous bats are much smaller and quieter.

The insect-eating bats are among only a few groups of species that use echolocation to navigate, hunt and communicate with each other.

“Echolocation is an ultrasonic call and it’s inaudible to human ears, so often we don’t know that the bats are around us and the ecosystem services they’re doing,” Ms Peterie said.

“Bats have a signature call, so we can use these calls to identify what species is present, and then we’re able to share with the landholders exactly what bats were found on their property and some information about these bats.

“So everyone might have bats on their property, but they just don’t know that they’re there.”

‘Really special’

Last year, 110 participants in Narrabri, Wellington, Western Sydney and the Pillar Valley recorded 95,996 bat calls.

The study identified 24 bat species, including nine that were threatened and one believed to be extinct.

Wellington resident Tessa Ponder took part in last year’s survey and was astounded with the results.

“We were very surprised about how many bats were actually recorded, because in my mind it was late in the season and I thought perhaps they’re not going to get anything,” she said.

Narrabri property owner Jessica Stuart also took part and uncovered nine species of bats surrounding her land.

“Two of them are quite endangered or rare species, which was really interesting to learn about,” she said.

“There’s something we can learn about the piece of land we have that’s just really cool.

“Because we can’t see these creatures and to know that they’re hiding somewhere it’s really special.”