Disease management
Published: 08/04/2008
The Save the Tasmanian Devil Program's disease management strategy is focused on the key areas of:
- Population monitoring - Gathering data in the field to clarify DFTD distribution and impacts, and to help determine conservation strategies.
- Disease diagnostics - Laboratory-based investigation of DFTD itself, which includes defining the disease, and exploring its transmission and possible ways to fight it.
- Wild management - Methods used for managing the impact of DFTD in the wild.
- Insurance population – An Insurance Population of healthy Tasmanian devils, housed throughout Australia, for reintroduction into the wild if necessary.
Find out what you can do to help save the Tasmanian devil
Population monitoring
During a workshop held on the 16 October 2009 by the Management and Monitoring team of the Save the Tasmanian Devil Program, it was decided that the current long-term monitoring strategy of trapping at three sites (Mt. William, Fentonbury and Freycinet) had achieved its aim. It was decided that a new, more pro-active, monitoring strategy should be implemented for two reasons:
- To progress our knowledge on devil populations, their response to the disease, and the disease itself, to the next level.
- To maximize time and cost efficiencies, making ongoing monitoring more sustainable.
The new monitoring strategy has been designed to answer the following questions:
- Is there local extinction in a diseased population?
- Is a population reacting atypically to disease?
- Where does the current disease front lie?
These questions can be answered to some extent using cameras, rather than the more expensive (time and monetarily speaking) trapping.
Question #1 requires presence/absence data only, which is easily captured using cameras and a staked carcass to lure devils to the camera site.
Question #2 will be answered initially by monitoring chosen sites using cameras to give an indication of relative devil abundance and age structure. If the resultant analysis gives results that are unexpected for that population (either complete absence of devils or a greater abundance/older individuals) then a trapping trip to the site would then clarify the status of the population.
Following disease front trapping trips in October 2009, it is felt the best way to answer Question #3 is to place sentinel cameras (cameras left in place indefinitely) along the disease front (north to south) in transects running east – west. If we simply use the six areas trapped recently as the areas to run these transects through, and run 5 cameras along an east – west transect with 5 – 10km between each camera (a total of 30 cameras), we can get a very good idea of where the disease front lies on a continuing basis. If a camera shows a diseased devil in a westerly location not previously known to be diseased, a trapping team would be deployed to this site to obtain confirmation of disease. As disease is located at camera sites in the east, these cameras would then be moved to sites to the west of the most westerly cameras. In this way we will have a revolving line of cameras that constantly inform us where disease is currently located. And by having the cameras operational all the time we stand our best chance of gaining some knowledge about devils, and possible disease, in areas of very low devil density.
A stratified sampling design for placing cameras is currently being prepared to answer Questions 1 and 2 with some degree of scientific rigour which allows a degree of comparison between sites and between surveys within a site.
This new, pro-active monitoring strategy will be sustainable on a long-term basis, past the expiry date of our current funding. As the disease, and the devil decline, is not going to stop once our funding runs out in 4 years time we must consider how to continue an effective monitoring strategy into the future with a large reduction in resources. We feel the use of cameras will help us do just that. There is an initial cost in outlay when purchasing the cameras, but the continuing cost is much reduced compared to the cost of trapping.
Find out more about remote camera monitoring.
See what the Save the Tasmanian Devil Program gets up to
View a movie (1 minute 29 seconds) showing members of the Save the Tasmanian Devil program staff checking trap sites in the Central Highlands of Tasmania. The specially developed traps are checked on a daily basis and animals are carefully examined by veterinary officers for signs of the disease before being released back into the wild.
Disease diagnostics
At the Animal Health Laboratories (AHL), Tasmanian Department of Primary Industries, Parks, Water and Environment scientists have collected and analysed blood, tissue and tumour samples from hundreds of Tasmanian devils, allowing a growing understanding of the nature and origin of Devil Facial Tumour Disease (DFTD). Through this work, and the work of collaborators, we now know the tumour is of nerve cell origin and is spread between devils by direct cell transfer. The initial published work in the November 2006 editions of Veterinary Pathology and Nature established these facts.
Recently published work in Science (2010) confirms the possible nerve cell origins of the tumour using genetic techniques. Other genetic work undertaken by the AHL has shown a continuing genetic evolution of the tumour and unravelling the significance of this finding is an ongoing part of our work.
AHL's diagnostic work continues on a daily basis supporting many aspects of the Save the Tasmanian Devil Program (E.g. disease suppression, captive animal health monitoring and treatment trials) and has facilitated the establishment of a data base of information and tissue archive of DFTD cases for many ongoing projects and future work. They are also developing much better tools for tumour diagnosis and assessment of health in Tasmanian devils.
Wild management
Since 2006, scientific officers have been removing diseased Tasmanian devils from the geographically isolated Forestier-Tasman Peninsula in an attempt to contain the impact of DFTD. The Tasman Peninsula was chosen because its physical geography minimises the entry and exit of animals, offering an opportunity to create a disease-free region.
Results, as at December 2009, suggest that this work has not led to the local eradication of the disease.
The project’s effectiveness may have been influenced by the possibility that infected devils are passing on DFTD before they’re being trapped and removed. A diagnostic blood test that confirms DFTD before the devil develops tumours is currently being validated and could be a major breakthrough for disease suppression.
Another factor influencing the effectiveness of the work may be the presence of a ‘cryptic population’ of devils – animals that, for whatever reason, are not being caught in standard traps. The cryptic population, which seems to be around 25%, could be acting as a disease reservoir.
The Save the Tasmanian Devil Program is currently trialling alternative trapping patterns and designs to increase the chances of reaching members of the trap-shy cryptic population.
Nipping DFTD in the bud - latest news from the Peninsula - August 2010
Insurance population
The Save the Tasmanian Devil Program began building an Insurance Population in 2005. It has been very successful in establishing a population of healthy animals that could, if needed, be reintroduced into the wild.
As at January 2010, the Insurance Population had grown to 277 disease-free Tasmanian devils.
Find out more about the
Insurance Population.
How you can help
There are four ways that you can help to save the Tasmanian devil.
- Report sightings of live diseased Tasmanian devils on 6233 2006.
In your report, include: details of the location and condition of the animal and your contact details (including telephone number). Members of the public should never touch Tasmanian devils under any circumstances. They are wild animals and they might be diseased, even if you can't see tumours.
- Find out about our Roadkill Project for reporting Tasmanian devil roadkill sightings.
- Find out about our Volunteer Program.
- Find out about our official fundraising arm, the Save the Tasmanian Devil Appeal.
