How many frogs are killed on a road in North-east New South Wales?

Abstract

Road impacts on Australian frogs are poorly documented. This limits our ability to predict which species may be vulnerable to impacts and to develop strategies for mitigating impacts. We conducted foot-based surveys for road-killed frogs along two 100-m sections of a road that traverses known frog habitat near Lennox Head, in north-eastern New South Wales. More than 1000 dead frogs were counted over 13 mornings. Two threatened species, the Wallum Sedge Frog Litoria olongburensis and the Wallum Froglet Crinia tinnula, accounted for at least 60% of these roadkills. It is estimated that in an average summer period, there would be ≯40,000 frogs killed on the 4-km span of road through the heathland habitat. That is, ≯10,000 road-kills of each of the Wallum Sedge Frog and Wallum Froglet. Research is needed to ascertain how severe this impact is on these isolated populations and to determine how road mortality of frogs can be minimized.