Traffic impacts on cassowaries

Road mortality is the greatest cause of known cassowary deaths at Mission Beach. Between 1992 and June 2010, at least 60 cassowaries died on local roads. At the request of Terrain NRM, James Cook University (JCU) undertook significant research into traffic impacts on cassowaries (and other fauna) on Mission Beach roads. 

The report is divided into seven sections, addressing different aspects of the risk and management implications:

  1. Review of ecological impacts of roads
  2. Road impacts on cassowaries:
    1. identified road crossings
    2. cassowary use of individual crossing zones
    3. cassowary behaviour when crossing roads
    4. latest cassowary roadkill data: DERM and Tully Veterinary Surgery
  3. Analysis of traffic volume and speed on the two entry roads and relationship with traffic calming trialled on those roads
  4. Roadkill data of other species along Tully-MB and El Arish-MB Roads. Use of potential culvert underpasses and Hull River bridge for crossing by vertebrate animals
  5. Review of mitigation measures trialled around the world
  6. Risk analysis for individual crossing areas with possible mitigation options
  7. Synthesis – towards an integrated strategy
The research demonstrated that cassowaries use of roads and behaviour around roads is unpredictable and differs between individuals, however, sudden loud noises (like trucks or cars with trailers) will frighten most. Their response is unpredictable – sometimes cassowaries will run across the road in front of the vehicle, sometimes they will retreat back into the forest. The mean time spent crossing the road is 13.5 secs.
As with most wildlife mortality (and indeed human mortality) on the road, speed is a significant factor in cassowary deaths, and it should stand to reason that reducing speed limits can help to reduce mortality by increasing drivers time to react. Unfortunately, reducing speed limits doesn’t necessarily mean that drivers will respond, and the study showed that on the Tully-Mission Beach Road most drivers average well above the speed limit. The highest speeds recorded were a shocking 180kmph by a car and 165kmph by a truck in an 80kmph zone! 
Permanent roadside warnings signs were shown to have some impact on visitors but are often ignored by locals, with temporary signs (such as “recent cassowary crossing” signs and signs with flashing lights and variable messages) more likely to result in a slight reduction in speed (5-10kmph). Other traffic calming measures (such as rumble strips and painted lines across the road) proved largely ineffective as drivers quickly become habituated to them.
To be effective, measures to reduce cassowary mortality on the roads around Mission Beach require community support, including a heightened level of driver awareness, and greater enforcement of speed limits by authorities and community members. Terrain NRM and JCU will be working together to organise community workshop/s to seek consensus of how to reduce the risks, and members of the Cassowary Recovery Team will be visiting some of the “hotspots” for cassowary mortality to investigate potential site-specific management measures.
How you can help:
  • SLOW DOWN in cassowary habitat
  • Encourage others to do the same
  • Report dangerous driving
  • Add a cassowary “Take Care” bumper sticker (available from WTMA and many visitor centres, like C4) to your car

This valuable research by Miriam Goosem, Leslie Moore, Peter Byrnes and Marina Gibson, was funded by Terrain NRM, Queensland Department of Transport and Main Roads (DTMR), the Marine & Tropical Sciences Research Facility (MTSRF) and the School of Earth and Environmental Sciences (SEES) at James Cook University.