The bats live in the Cliefden Caves, along the Belubula River, which are at risk of being flooded if the state government goes ahead with a proposal to build a 90,000 megalitre dam at the site. 

Hundreds of eastern bentwing bats live in the caves and according to  Orange Speleological Society vice-president Denis Marsh the bats are an essential part of the region’s ecosystem. 

Unlike fruit bats, the two species of bats that live in the caves, the bentwing and the horseshoe bats eat insects and can eat half their body weight in insects in a night.

“They’re really important for the local vineyards because they eat insects which might eat the fruits,” he said. 

Mr Marsh said the Cliefden Caves were the “maternity site” for the horseshoe bats and these bats were very susceptible to disturbances of their maternity site. 

He said if the site was disturbed the population would be destroyed. 

A committee called the Save the Cliefden Caves Campaign Committee was formed after the announcement, in June, by the state government that it would fund the project.

Mr Marsh said the group was marshalling experts in a range of scientific fields to gather as much evidence as they could to present arguments as to why the dam should not be built. 

A petition called “Save the Cliefden Caves, NSW, from flooding by proposed dam” and addressed to Premier Mike Baird has attracted 333 signatures since July 1. 

Member for Orange Andrew Gee was not available for interview but said in a statement he could understand why the caves committee was concerned. 

“They certainly need to be listened to, and we need to have qualified people address those concerns,” the statement said. 

“These issues will all be addressed. But let’s not put the cart before the horse. We don’t even know if The Needles is to be the preferred site. Another site may be preferred. It’s just too early to say what will happen.”