Threatened species and lead ecotoxicology

What is the association between Tasmanian devils (Sarcophilus harrisii), wedge-tailed eagles (Aquila audax), toxicological threat and ammunition? Dr Michael Lohr discovered the answers during two studies undertaken which were recently published.

One critical way in which anthropogenic activities harm wild animals is through environmental pollution, recently recognised by the United Nations as the third global catastrophe (along with climate change and biodiversity loss) (United Nations, 2021). Lead (Pb) is a persistent and toxic element that historically had many environmental sources (e.g. paint, fuel), which have been progressively reduced through environmental regulation. Lead pollution is a typical One Health problem, which is defined as negatively impacting humans, as well as other animals, plants and ecosystems (Arnemo et al., 2022; Demayo et al., 1982).

In wildlife, the consequences of exposure to spent lead-based ammunition have been most extensively studied in avian species. Scavenging species such as the California condor (Gymnogyps californianus) have been comprehensively studied and shown to be negatively impacted by lead-based ammunition, this being the primary factor that nearly caused the extinction of the species.* In Australia, this effect has also been studied and demonstrated in wedge-tailed eagles (Aquila audax).**

Additionally, there is a growing recognition of the harmful effects of lead exposure on mammalian scavengers. Tasmanian devils (Sarcophilus harrisii) are the focus of intense conservation efforts, including efforts to proactively identify any other threatening processes that may prevent or delay recovery of the species, including toxicological threats from anthropogenic activities such as lead derived from ammunition.

Click below to learn more about these connections and environmental impacts as discovered by our Principal Zoologist:

• Lead exposure of mainland Australia's top avian predator - ScienceDirect
• Further investigation of lead exposure as a potential threatening process for a scavenging marsupial species - Hutchinson - Australian Veterinary Journal - Wiley Online Library

* Reference: 5, 6 from Further investigation of lead exposure as a potential threatening process for a scavenging marsupial species

** Reference: 7-9 from Further investigation of lead exposure as a potential threatening process for a scavenging marsupial species