A 6-year study of mitigating koala roadkill during an upgrade of the Pacific Highway at Lindsay’s cutting, Coffs Harbour New South Wales

Abstract

This 6-year study aimed to monitor a local koala population and koala protection/mitigation measures before, during and after a major upgrade to the Pacific Highway at Lindsay’s cutting near Coffs Harbour in northern coastal New South Wales. This represents the scale of the individual koala interacting with traffic on a primary road within a well-studied Local Government Area for koalas. We also collected records of koala road injury and death from local wildlife carers. The principal findings were that, before the upgrade or any mitigation provisions, koalas were regularly killed on this 1 km stretch of highway flanked by primary koala habitat (26 records 1991–97). Koala exclusion fences largely eliminated the roadkill here, but the benefits were highly localised. Koalas made occasional use of a wildlife underpass below the highway. Two problems were identified: a farm gate left open in the fence allowed koalas onto the highway, and koalas could walk around the fence ends onto the highway. On the positive side, we have shown the value of local-scale research and mitigation, such as koala exclusion fences, and the value of examining the koala population of the surrounding area to assess the effectiveness of this mitigation at a larger scale.