Short-tailed and long-tailed bats are native to New Zealand and their conservation is important to Catriona Gower, who spearheads the Catlins Bat Project with support from Forest and Bird.
She is hosting a night walk tonight to try to spot the small nocturnal mammals in their natural Catlins environment.
Anyone was welcome to attend, she said.
She wanted to use the opportunity to educate people about the bats and the work she did surveying the two species.
High-tech ultrasonic receivers would be used to locate and listen in on the bats' echolocation sounds, which were at a frequency too high for human ears to pick up.
People loved hearing the sounds of the bats and seeing them in their natural habitat, she said.
"You can just see on their faces they're just thrilled. It's like magic coming out of the darkness.''
Ms Gower could identify different types of calls being made and from which species of bat they came.
Environmental factors, such as the moon being out, could influence whether any bats came out.
She went on a night survey earlier this week to spot the bats and listen for calls on the ultrasonic detector.
It was important to raise awareness about the bats to ensure their survival, she said.
A third bat species native to New Zealand, the greater short tail, was last seen on the Solomon Islands in 1967.
The two remaining species were threatened and protected under the Wildlife Act.
As each female bat produced only one pup per year, it was difficult to maintain a steady population, Ms Gower said.
Those wanting to go on the walk should bring a torch and be prepared to stay out late.
Those interested should meet at the Tahakopa Hall at 9.15pm.
