A Translocation program was prepared by Red Sand Ecology for the Department of Transport and Main Roads in association with the Roys Road Bruce Highway Interchange Upgrade. Ecological assessment undertaken at the site confirmed the occurrence of three endemic acid frog species – the Wallum Froglet (Crinia tinnula) and Wallum Rocket Frog (Litoria freycineti) both listed as Vulnerable under the Nature Conservation Act 1992, and the Wallum Sedge Frog (Litoria olongburensis) listed as Vulnerable under the Environmental Protection and Biodiversity Conservation Act 1999.
To avoid impacts to critical habitat and breeding areas of the specialist species, an Acid Frog Species Management Plan was implemented, including establishment of compensatory ponds and an experimental strategy that imported ‘slabbed’ optimal habitat from local wallum heathland.
The 24-month monitoring program including visual searches, acoustic surveys and habitat condition assessments found that all three species were actively using supplemented ‘slabbed’ habitat areas. Species occurrence correlated with establishment of characteristic wallum vegetation in conjunction with shallow, somewhat tannin-stained water with low turbidity, and pH.
Given that habitat quality continues to improve with further upstream stabilisation, the site will continue to support viable breeding populations and maintain connectivity to surrounding areas of habitat. This is essential to facilitate gene flow between subpopulations in surrounding areas, which is crucial to the local persistence of acid frog species.