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Published: 2007-01-31 00:00:00

Hamilton may be a far cry from Gotham City, but it has its very own “batgirl”.

Her name is Andrea Dekrout and instead of fighting crime, she’s fighting ecological decline.
Her mission: to complete her PhD on the ecology of the New Zealand long-tail bat in fragmented urban habitats.

Environment Waikato is lending some financial support to the project with a grant from its Environmental Initiatives Fund.

Anecdotal evidence suggests long-tail bats have been in Hamilton for at least 20 years and Andrea wants to find out what keeps them here.

The Auckland Univeristy student, who is living in Hamilton to carry out her work, spent a large part of last week in Hammond Park trying to trap the little critters in a huge net.

Once she’s captured the bats, she fits them with fingernail-sized tracking devices, lets them loose and races around tracking their ultrasonic signals with radio equipment. It’s no mean feat, as they can travel at speeds of up to 60 kilometres per hour.

“I described it to my research assistant as bursts of activity followed by long periods of boredom,” she said.

“But it’s really good fun and it’s almost like a puzzle; once you’ve found them with transmitters you have to try and figure out where they’re going and what they’re doing.”

Bats are New Zealand’s only native land mammals. Long-tail bats weigh about 10 grams and feed on small moths, midges, mosquitoes and beetles.

Andrea is hoping her discoveries will enable their habitat to be extended in Hamilton.

“Nobody really knows what the population size is, but the long-tail bat is a category B threatened species and without any management it could disappear within 10-20 years,” she said.

She believes their population is more likely to be in the dozens than the hundreds.

“However we think with good management the population could reach healthy levels in the long term. When people have rare native animals right in their city it helps encourage conservation attitudes overall.”
One of the most interesting things about Andrea’s study is that she’s captured 26 male bats, but only one female, which, agonisingly, was fitted with a faulty transmitter.

“It was terribly gutting – I spent three days sitting out in the park trying to hear her – but we know she’s there now so we’ll catch her again.”

She’s also discovered there are lots of bats in the south end of the city, and particularly in Hammond Park, where they can connect with other bush areas near Hamilton’s fringes.

Long-tail bats like lowland habitats such as the Waikato, but most of their potential habitat has been destroyed by humans.

To ensure her study is not selecting for bats that are easy to catch, Andrea recruits volunteers to carry out city-wide “bat blitzes” every six months. She divides the whole city into blocks and sends volunteers off walking pre-planned routes to track the bats’ ultrasound signals. The next bat blitz is coming up in March.

Hamilton’s “batgirl” isn’t fighting crime, but she has recently been a victim of it. Andrea is pleading for the public’s help in retrieving a $12,000 radio receiver that was recently stolen from her flat.

“It is absolutely no use to anyone except those doing wildlife tracking and it was probably just picked up because it looked expensive and electric,” she said.

“I’ve been able to carry on without it, but its theft puts a strain on the budget of the entire biology department, which is doing a lot of conservation work. We would love to have it back.”

Andrea can be contacted at adek004@ec.auckland.ac.nz.