Protecting endangered Tasmanian devils and their parasites

10 May 2017

  • A Giardia strain of parasite from humans has been detected in Tasmanian devils
  • Human contamination of waterways and encroaching on the devils’ habitat could be potential pathways of parasite introduction to devils
  • New types of both Cryptosporidium and Giardia parasites have also been found in Tasmanian devils
  • These new types of parasites are potentially only found in Tasmanian devils and may therefore also be endangered

While the endangered Tasmanian Devil population is already being threatened by the transmissible devil facial tumour disease, researchers from Macquarie University and the Save the Tasmanian Devil Program in Tasmania have found evidence that we humans could also be distributing another problem among this endangered wildlife species: our parasites.

“We found that Tasmanian devils harbour strains of Giardia that are commonly found in humans,” explained author Liana Wait from Macquarie University, “and the detection of a strain called Giardia duodenalis BIV indicates a recent human-to-devil transmission event.”

The Giardia and Cryptosporidium parasites, that the researchers were investigating in the study, are spread in faeces of infected hosts and are transmissible via contaminated water.

“Human encroachment into the devils’ habitat, through actions such as the dispersal of wastewater from humans or swimming when suffering diarrhoea, could potentially be introducing new parasites to Tasmanian Devils, as these parasites are not normally part of their wild habitat,” explained Dr Michelle Power from Macquarie University.

“Much of the research on devils has investigated devil facial tumour disease. However, other disease threats that have the potential to thwart Tasmanian devil health and population recovery also need to be considered,” she continued.

In addition to the human strain of Giardia, new types of both Cryptosporidium and Giardia were also found in devils, and these are likely to be new parasite species.

“Parasites are more renowned for their ability to cause disease; however, these parasitic organisms are integral to the ecology of their hosts and the biodiversity of the planet,’ explained Dr Power, “as we lose many of our wildlife species we are also losing these important parasites that are often specific to their wildlife host.”

Cryptosporidium and Giardia were found in greater numbers of wild animals, with around 24 to 38 per cent of wild animals found to be infected with either parasite, compared to captive devils, which were only found to have between 0.8 to 25 per cent of either parasite in their population.

“We need to ensure that wildlife and their parasites are conserved, and this is an important goal of the Save the Tasmanian Devil Program,” explains Dr Samantha Fox from the Save the Devil Program.

“By studying the threats posed by introduction of new parasites and the diversity of their endemic parasites, we hope to gain more insight into how to help take these animals off the endangered species list and preserve their unique and important parasites,” she concluded.

Wait, Liana F; Fox, Samantha; Peck, Sarah; Power, Michelle L. Molecular characterization of Cryptosporidium and Giardia from the Tasmanian devil (Sarcophilus harrisii). Plos One. April 2017. DOI: 10.1371/journal.pone.0174994

Filed under: Featured Research Science & nature