Researchers from the University of Tasmania are fitting juvenile siblings Christopher and Callie with tracking collars that will measure for the first time not only who the devils interact with, but also where they go, thanks to the novel combination of proximity sensing and GPS technologies.
The pair, who call Bonorong Wildlife Sanctuary in southern Tasmania home, are providing vital feedback on collar performance before the new technology is deployed in field trials on adult devils later this year.
Disease ecologist Dr Rodrigo Hamede, from the School of Natural Sciences, has been studying DFTD transmission for 16 years and expects the new collars will provide fresh insight into devil behaviour and social networks.
“Our aim is to reveal how devil movements and social networks influence the transmission and persistence of devil facial tumour disease. We will be able to link transmission events, from individual to individual, through the population and across landscape features,” Dr Hamede said.
“We have a wonderful opportunity to immerse ourselves in the complex world of devils and are hoping to reveal every possible detail about the nature and scope of devil interactions and their relevance for DFTD transmission.”
Many of the University’s previous research endeavours have benefited from the support of Bonorong Wildlife Sanctuary, and manager Greg Irons was happy to volunteer two of his captive devils to trial the new collars in a controlled environment before their field debut.
“We have a unique opportunity with captive animals to be able to test things that would be a lot easier to test here than out in the field. If the researchers can perfect it here, so it works better for the animals out there and causes less stress and more importantly aids the research, then that’s a fantastic role we can play.”
A uniquely Tasmanian marsupial
The Tasmanian devil is a carnivorous marsupial that was once native to mainland Australia but is now only found in the wild on the island state of Tasmania.
The first case of DFTD, a transmissible cancer characterised by the appearance of obvious facial tumours, was reported in 1996 at wukalina/Mount William National Park. Ongoing research into the disease has helped shine a light on the plight of this much-loved marsupial.
“Fifteen years ago, we knew very little about this disease, and the future for devils was extremely dire. We have witnessed dramatic population declines across Tasmania, and the reality is that we have an infectious cancer that is not going to disappear in the short to mid-term, and I would dare to say in the long term,” Dr Hamede said.
“However, devils are fighting back, they are becoming better at coping with this cancer. The tumour is evolving too, and recent evidence suggests that devils and DFTD are learning to coexist with each other. This is what diseases need to do, because the demise of a population is also the end of the disease.”
Identifying disease hotspots and superspreaders
For any infectious disease transmitted by direct contact, it’s essential to know where individuals gather, where the hotspots are and how those hotspots influence daily social networks. Another key piece of the puzzle is identifying the major players, or superspreaders, in transmission events.
We’ve recently seen proximity sensing technology deployed in the investigation of human diseases such as COVID-19, and the new collars will enable researchers to gather the same comprehensive data on Tasmanian devils.
In November 2020, PhD candidate Georgia McGee will be fitting collars to 20-25 devils on the Freycinet Peninsula, monitoring their movements and gathering detailed data on their interactions for about 12 months. She then has the challenging task of recovering the collars and analysing the results in the lab.
“The collars will continuously gather data 24 hours a day, seven days a week, so in terms of being able to follow a wildlife disease it doesn’t get any better than this,” she said.
“We currently have a lot of unanswered questions when it comes to the influence of landscape and devil social structure on the transmission of DFTD, so the opportunity to essentially go where the devils go and find out who they’re interacting with is really exciting.”
Professor Menna Jones has conducted research on devils and their tumour disease on the Freycinet Peninsula for 22 years and is Georgia’s supervisor on this project alongside Dr Hamede.
“Studying devils on a large and rugged peninsula like Freycinet gives a very detailed understanding of how topography influences how devils use landscape and where they congregate. The mix of conservation area and agricultural land can point towards how we might manage the landscape to help devil conservation,” Professor Jones said.
Looking to the future
Significant progress has been made over the last decade towards understanding DFTD, with comprehensive epidemiological data and samples gathered thanks to an international collaboration led by the University of Tasmania that involves researchers from Australia, Europe and the United States.
We are witnessing evolution in action, Dr Hamede says, as we learn more about the way devils adapt against cancer and the changes in their social networks, spatial and behavioural ecology.
“In that sense, devils and DFTD are becoming a model system to understand how wildlife populations adapt and respond to novel disease threats,” he said.
“This is great news not just for devils, as our findings are certainly applicable to many other species affected by wildlife diseases. We hope to use some of these concepts and novel approaches to better understand and manage future epidemic outbreaks in wildlife.”
About Dr Rodrigo Hamede
Dr Hamede specialises in disease ecology and epidemiology but he is often involved in collaborations with researchers from a broad range of disciplines including, genomics, immunology, veterinary medicine mathematical modelling and evolutionary biology.View Dr Rodrigo Hamede's full researcher profile