The micro bats, small insect eaters called Southern Myotis or fishing bats, were found during environmental studies of the bridge on Markwell Road. Sound detectors picked up the sounds of flying bats, which are undetectable to the human ear. 

It is believed about 20 bats live in the bridge.  

The rare species normally roosts in small groups in caves, mines, tunnels, culverts and other enclosed structures, usually near water.  Cavities in timber bridges provide ideal homes for this listed threatened species.  

Council's ecologist Ryan Sims, who found the bats, said the discovery was exciting. 

“Fishing Bats are rare and fascinating creatures. They perform valuable ecological functions and, being listed as threatened, council has a legal responsibility to protect and manage them,” he said. 

The bats will be provided with alternate roosts, with a bat box provided nearby. 

The roost cavity would be closed after the bats left for a night’s foraging and then a suitable permanent roost box would be provided under the new concrete bridge, council’s senior ecologist Mat Bell said. 

Roads and Maritime Services have been advising council on the relocation, as Southern Myotis bats have previously been moved from under timber bridges into purpose-built bat boxes under new concrete bridges in the north of the state.