The Game Management Authority conducts the following environmental research.
The GMA is conducting research into lead exposure in Victorian birds of prey.
Lead poisoning of waterfowl and other birds that ingest lead shot has been recognised for decades. Many countries have banned the use of lead shot for duck hunting, including most of Australia. Victoria banned its use for duck hunting in 2002. There is now growing worldwide recognition of the threat posed by toxic lead-based bullets on wildlife that consume lead fragments left in gut piles, discarded carcasses or escaped wounded animals. This has led to an increasing number of studies to assess lead exposure levels in birds of prey (raptors) around the world. Recent Australian research has shown considerable lead exposure in scavenging raptors, such as the mainland Wedge Tailed Eagle and the endangered Tasmanian Wedge Tailed Eagle.
This research aims to better understand the contributors to lead exposure in Australian birds of prey. Specifically, the research focusses on understanding the contribution of hunting to environmental lead contamination. The GMA will conduct research to trial cost-effective methods for measuring lead exposure in bones of Victorian Wedge Tailed Eagles from existing specimens.
It is anticipated that the research will conclude in 2021.
Researchers from the University of Melbourne with financial support from the GMA studied two different methods of lead detection in animals to determine if one method was more accurate than the other. The more commonly used plasma mass spectrometry scanning machine was compared with the new portable handheld X-ray device. The study also provided the opportunity to examine bone lead levels in wedge-tailed eagles (Aquila audax) from east Gippsland and Tasmania.
Results showed that both methods of lead detection produced similar results, suggesting that the new portable X-ray device could be a useful and inexpensive option that is less destructive to the analysed specimens.
The study also found that over 50 per cent of the eagles examined had elevated lead levels (>10 mg/kg) and 13 per cent had severe lead exposure (>20 mg/kg).
The severe level of exposure to lead found in 13 percent of Victorian wedge-tailed eagles was found in just one per cent of Tasmanian wedge-tailed eagles. This difference may be explained by the hunting and animal management practices that occur in the area.
South-eastern mainland Australia is likely to be one of the highest risk places in Australia for exposure to lead from ammunition, with year-round recreational deer hunting, culling of kangaroos and unregulated culling of pest species. Aerial shooting has been increasingly used to control deer in south-eastern Australia and may represent a significant source of ingestible lead to scavenging wildlife. This study suggests that continued research into the impacts of lead-based ammunition on native wildlife should be a high conservation priority.
The negative effects of exposure to lead from bullets have been reported from numerous scavenging bird species around the world. The symptoms of lead exposure in birds reportedly range from impaired movement, including the inability to fly, to immobility and death. Until recently, there has been little investigation of the impacts that lead may have on native Australian wildlife, particularly raptors.
See the full study: Portable X-ray fluorescence for bone lead measurements of Australian eagles
Page last updated: 05 Sep 2022