On the hunt for tiny, rare bats

This summer Karina Hadden will become bat girl. She won't have any super powers but she will be hot on the trail of the elusive long-tailed bat.

Karina Hadden is on the hunt for long-tailed bats.

The Lincoln University Bachelor of Science student is taking part in a summer scholarship project which involves helping to determine whether any of the rare animals are still living on Banks Peninsula.

She is studying conservation and ecology but until she found out she had been chosen for the scholarship a few weeks ago, she didn't have any specialist knowledge of bats. "I thought bats seemed pretty interesting and it looked like a cool project."

The 10-week role is funded by Christchurch City Council and supported by the Department of Conservation (DoC) and Banks Peninsula Conservation Trust.

Karina will soon start positioning about 50 acoustic recorders at different locations around the peninsula, such as under rock faces, near cave entrances, in stands of native podocarp forest such as totara and kahikitea, and near streams.

The recorders are activated only when they detect the exact frequency used by this species of bat, which they emit as they leave their roosts to hunt.

Karina will analyse the results and write a report which will be used in DoC’s national database. The 21-year-old starts the work early this month and will have help from other volunteers and her supervisor Mike Bowie, as well as DoC staff.

The long-tailed bat or Chalinolobus tuberculata has become so unusual that Karina is unsure if she will find any. There have been some possible bat sightings by members of the public around Banks Peninsula but they haven't been officially recorded there since the 1960s. A population survey in the 1990s failed to find any.

The tiny creatures used to be common in the South Island and there were reports until 1885 of the bats roosting under wooden bridges near the Avon River in Christchurch. But in recent years as their native habitat has diminished the population has fallen dramatically.

A long-tailed bat. Photo by Sabine Bernert courtesy of DoC

There are some small colonies of long-tailed bats in rural areas around Geraldine but this is the only known population in the eastern South Island. "They're scattered around the country and some offshore Islands, such as Stewart Island and Little Barrier Island," Karina says.

"They're really small so they're hard to see and they move every night from their roost site which could make it difficult to find them. If we do find some, DoC is probably going to try and catch them and attach transmitter tags to them. That will allow them to protect those roost sites."

Long-tailed bats are closely related to an Australian species and it is thought they blew across the Tasman to New Zealand about two million years ago. The long-tailed bat and a short-tailed species are the only bats native to New Zealand. The short-tailed variety is also endangered and both bat species are a high priority for conservation.

Karina is calling on members of the public to help with the project by reporting any bat sightings to her at karina.hadden@lincolnuni.ac.nz.