Another threatened species has been found in the same area which could be flooded under the NSW government's plan to raise Warragamba Dam wall.
The vulnerable-listed painted honeyeater was discovered by Australian National University researcher Ross Crates last week in the Burragorang Valley which sits within the Blue Mountains National Park.
Mr Crates says the bird is rarely seen that close to Sydney or the coast and suggests they are most likely seeking drought refuge.
"If they start losing their drought refuge due to the dam proposal, it's not going to end well," he told AAP on Thursday.
The plan to raise the dam wall by about 14 metres will see the area flooded through a "controlled release" of water which Mr Crates says will mean the species will lose its habitat alongside the critically endangered regent honeyeater.
Australian Associated Press