Sarah Bekessy,a professor with RMIT's Centre for Urban Research said agriculture and then urban sprawl have left less than 1 per cent of the original basalt grasslands near Melbourne and less than 3 per cent of Sydney's Cumberland plains habitat.
"Areas that are wet and fertile and flat are really good for us and are really good for biodiversity too,"Professor Bekessy said.
"Housing developments are typically a very hostile land-use for biodiversity."