Chris Thomson

Chris Thomson

Abstract | Approaches to positioning crossing structures to facilitate emu movements across a major highway

1. What was the problem / situation?

Research conducted for the Pacific Highway upgrade between Woolgoolga and Ballina on the NSW north coast identified a population of coastal Emu, listed as endangered under the NSW Biodiversity Conservation Act, as being at risk due from the project. The challenge entails dealing with small numbers of emus that occupy a broad landscape mosaic of both natural and modified habitats. Being predominantly nomadic, non-breeding birds move from place to place without regard to season or direction and depend on resources that occur rarely at the same site. A continuity of supply can be ensured only if birds are able to locate successive favourable areas which are often spatially separated. Access to favourable areas may be via regular but broad movement pathways across the landscape. However, there is no available data to indicate where such movements pathways exist. There are two further problems, local emus are known to be vulnerable to vehicle-strike with numerous mortalities recorded in the 10 years prior to the study, and emus have not been recorded using underpass structures.

2. What worked

A strategy for identifying knowledge gaps, this included

  • Interviews with long-term landowners
  • Emu-vehicle collision study
  • Targeted survey to gather baseline data
  • Trial of temporary crossing zones

3. What lessons can be applied beyond your project, region or study species

  • Species vehicle collision data on other roads can be used for identifying hotspots on a new project
  • Trialling locations for crossing zones before design and construction of the project,
  • Using temporary fencing to simulate crossing zones and monitoring use of these by the target species

4. What would you do differently next time

Replicate sample areas across different landscapes and sites, particularly for the temporary fence trial, and types of crossings

Bio | Chris Thomson

Chris is Jacobs technical director for ecology with over twenty years’ professional experience managing biodiversity assessments and scientific reporting as a consultant. He is a highly experienced ecologist with extensive experience on linear projects, particularly roads, having worked widely throughout NSW as the technical lead on a range of environmental assessments including the Pacific Highway, Hume Highway, Great Western Highway, Princes Highway and New England Highway along with numerous large and small arterial road projects. Chris has extensive experience with fauna surveys for proposed road projects and has a high level understanding and experience with legislation and EIA guidelines relating to biodiversity impact assessments for major infrastructure projects, in addition to liaison with Government and public stakeholders, and the design and implementation of ecological monitoring programs and threatened species management plans