Tasmanian Devil

I know what you did last summer: chemical clues in the marsupial’s whiskers can reveal what they ate months – and even seasons – ago.

Scientists can peer at least nine months into a Tasmanian devil’s past by studying its whiskers, a new study led by UNSW Sydney has found.

The long, wiry whiskers on these stocky marsupials hold chemical imprints from food they’ve eaten in the past – records that can help tell broader stories about their foraging habits, habitat use and how they respond to environmental change.

Posted on behalf of the National Dingo Preservation and Recovery Program Inc. A recent academic publication explores the prospects of reintroducing the threatened Tasmanian Devil into forested south eastern Australia as a way of restoring ecosystems. Two important environmental objectives are considered in putting this forward: increasing the survival prospects of the devil itself which is currently threatened in Tasmania, and restoring ecosystems through the re-introduction of a top-order predator role in areas where the dingo (which currently performs this role) has been ‘extirpated’. This paper is important for dingo conservation advocates and organizations. This is because dingo conservationists have come to rely increasingly upon reference to the apex predator role of dingoes in making their case to governments. Further, what initially may seem an innocuous initiative for the re-introduction of devils to mainland Australia, on closer inspection is troublesome both politically and environmentally. First, an outline of the research and what it concludes. The starting point for the paper is that dingo culling has been linked to ecological cascades evidenced by eruptions of herbivores and introduced mesopredators (foxes and cats), and declines in small and medium-sized herbivores (including small mammal extinction). Increased herbivore populations have resulted in decreased understorey vegetation, which in turn has facilitated mesopredator predation upon small mammal species. The paper identifies mainland habitat where reintroduced devil populations may survive and models the potential effects of devil reintroduction for herbivore numbers, understorey vegetation recovery and small mammal numbers. It is concluded that reintroduction of the devil as an alternative apex predator would restore ecological balance. Suitable areas for devil reintroduction are identified down the NSW coastal region into most of eastern Victoria. The case for devil reintroduction, however, does not simply rely upon scientific argument. It is based on political judgements which cut to the core of current efforts to preserve the dingo as apex predator, including in south eastern Australian forested regions. Whereas, the title of the paper and some of the media coverage that it has attracted points to devil reintroduction in forested areas where dingoes ‘have been extirpated’ and ‘where dingoes no longer exist’, a closer reading indicates that devil populations are deemed to be incompatible with dingoes and that ongoing, intensive dingo control, through the use of 1080 poison, would be required over large areas to sustain devil populations. It can be presumed that such ongoing, intensive baiting may also occur in remote forested regions where devils would be re-introduced and where baiting is not currently carried out. Landscape scale baiting against dingoes would be deployed not only to protect sheep, but devil populations, perhaps at intensities and scales greater than at present. Here, we see an instance of where radical ecology converges with conservative politics. This is because a working assumption of the paper is that dingo conservation is not viable in areas where they are deemed to be an agricultural pest: "Because dingoes are a major pest to livestock producers the maintenance of dingo populations is an untenable option for wildlife managers in many regions of south-eastern Australia." (Hunter, et al., 2015: 429) Ultimately the credibility of the proposal for reintroducing devils to forested south-eastern Australia rests on the conservative (some would say reactionary) political assumption that dingo conservation in these areas is ‘untenable’ because of commercial agricultural considerations. Business trumps nature. The paper appears to be pandering to the anti-dingo prejudice of the pastoral industry in an attempt to rally support for devil reintroduction. There is no suggestion that the scale of dingo predation is often exaggerated by pastoral interests and reflects an uninterrupted, ingrained cultural prejudice from the early colonial period. In Victoria, a loss of around 3,500 sheep is recorded annually due to ‘wild dog’ predation, out of a population of around 20 million sheep. Historically, a ‘wild dog’ control industry has grown up around an exaggerated perception of the ‘wild dog’ threat and an unwillingness to recognize the ecological role of the dingo as apex predator. It is unfortunate that some scientists now appear to be using this entrenched prejudice as their starting point for a ‘scientific’ investigation into the plausibility of devil reintroduction. The ethical concerns about devil reintroduction, as conceived in this paper, go further. Other recent genetic research (Cairns, 2015) strongly suggests that there were two introductions of the dingo into Australia. One of these distinct dingo lineages exists in the south eastern forested regions of the Australian continent. What has been loosely referred to as the ‘Alpine’ dingo, it is argued, represents a distinct genetic lineage and not merely a regional adaptation. The very areas where this distinct dingo lineage exists are the areas targeted in the devil reintroduction paper. To explore opportunities for expanding the range of the Tasmanian devil, including onto mainland Australia, is potentially defensible. But, to give credibility to such an endeavor by scaling up the ‘extirpation’ of another native apex predator, essentially for reasons of prejudice and commercial triumphalism, is deplorable – ‘science’ at its worst. (Hunter, D, Britz, T., Jones, M., and Letnic, M. (2015) ‘Reintroduction of Tasmanian Devils to mainland Australia can restore top-down control in ecosystems where dingoes have been extirpated’, Biological Conservation, 191, 428-435)

Here is a short report from University of Sydney about recent research which threw into doubt the role of genetic inbreeding as a factor in lack of immune defense against the killer tumours in devils.

Picture: "Tasmanian Devil." Photo by Rodrigo Hamede, University of Tasmania.

Mystery of Tasmanian devil tumour deepens – for now

The degree of genetic difference to a tumour rapidly decimating the ranks of Tasmanian devils (Sarcophilus harrisii) is not a factor in their likelihood of contracting the disease, according to research led by the University of Sydney.

The finding, published today in PLoS, the Public Library of Science journal, surprised researchers and means they will take a different approach in the race to better understand the Devil Facial Tumour Disease (DFTD), a contagious cancer which has already wiped out 85 percent of all Tasmanian devils.

“We looked at the West Pencil Pine population, in north-western Tasmania because they are the first population to be less severely affected by DFTD than other populations,” said Professor Kathy Belov, the senior author of the study from the University’s Faculty of Veterinary Science.

In West Pencil Pine there is lower prevalence of the disease, increased survival time of infected individuals and little indication of changes in population size or population growth rate, four years after the disease was first detected.

“We thought that differences in certain key immune genes might explain the different susceptibility patterns between devils in West Pencil Pine and other devils,” Professor Belov said.

Due to devil populations having low genetic diversity most Tasmanian devils share the same Major Histocompatibility Complex (MHC) genes as tumours. The researchers believed that since the tumours were genetically similar to individual devil’s own cells their immune system wouldn’t recognise that the cancer cells were foreign and wouldn’t attack them.

“Many of the devils at West Pencil Pine are genetically different to the animals in the east of the state. We thought these genetically different animals might be able to mount an immune response against the tumours,” Professor Belov said.

“We thought devils that were most genetically different to the tumours would be less likely to catch DFTD. This isn’t the case.”

The researchers will have to go back to the drawing board to try to work out why DFTD is affecting genetically different devils.

“It is possible the tumour itself is suppressing the immune response in some way. We also know that DFTD is evolving and changing over time. Perhaps the strain of DFTD in West Pencil Pine is different and that is why fewer animals are getting sick in that region,” Professor Belov said.

The next step will be to look more closely at the tumours in West Pencil Pine and at genetic difference across the entire devil genome, rather than simply focusing on the MHC genes. West Pencil Pine may still hold the key to why some devils catch DFTD and others do not.

The other contributing authors to the PLoS paper include Dr Amanda Lane, Yuanyuan Cheng, Belinda Wright, Dr Laura LeVan an and Dr Beata Ujvari from the University of Sydney and Dr Menna Jones and Dr Rodrigo Hamede from the University of Tasmania.

Media contact:

Verity Leatherdale: (02) 9351 4312, 0403 067 342 or verity.leatherdale[AT]sydney.edu.au

Photos of Tasmanian Devils are from this wonderful you-tube movie by Chris Coupland of a devil in the snow at Cradle Mountain. (The music may not be to everyone's taste but it suits the devil's walk.) Note that Tasmania's devils are so inbred due to isolation that somewhere round half now suffer from a fatal mouth cancer. For this reason vigilance must be of highest order.

Fauna protection in every state is a disaster!

Victoria isn't the only state that has received terrible criticism of their administering of fauna protection laws.
You only have to google for Auditor Generals' reports on fauna to come up with them for most or all states in Australia. Here are some examples:

Tasmanian Government

Threatened Species Report, Auditor-General of Australia, March 2009
http://www.audit.tas.gov.au/publications/reports/specialreport/pdfs/specialreport78.pdf

A damning report on the state of Tasmania's rare and endangered species by Australia's Auditor-General, was released in March, 2009 and among may issues notes how only 2 of Tasmania's threatened species have full recovery plans in place.

Tasmania's Southern Forests are habitat-in-crisis for many of these species.

“It was pleasing to find evidence that private forest covenants had been numericallyeffective but that only two public authority management agreements, which provide an effective mechanism to allow public sector entities to commit to arrangements for management of species and habitats, had been made.

Another concern was that the existing organisational structure did not encourage a strategic approach to conservation of threatened species, their habitats and the threatsconfronting them. However, a divisional plan with clearly defined objectives exists and performance against the plan was regularly monitored and results published.
The Report includes 19 recommendations primarily aimed at introducing a structuredand prioritised approach to managing Tasmania’s threatened species with a focus on assessing implementation plans and monitoring progress.”

West Australian Government

West Australia:
10 June 2009
Auditor General finds number of threatened species increasing and few are improving (West Australia)

With WA’s list of threatened species now over 600 and rising, Auditor General Colin Murphy has found that recovery action is not happening for most, and few are improving.

In his report tabled in Parliament today titled, Rich and Rare: Conservation of Threatened Species, Mr Murphy found that, in many areas, the Department of Environment and Conservation (DEC) is not providing effective protection and recovery to WA’s threatened flora and fauna.

“Only a handful of threatened species are actually recovering, while the number of species on the list continues to grow,” Mr Murphy said.

“My office has found that only one in five threatened fauna, and fewer than half of threatened flora species have recovery plans, and those plans that are in place are often not fully implemented.”

The report also found that DEC’s $8.2 million threatened species program prioritises recovery plans and actions towards critically endangered species, leaving vulnerable and endangered species at increased risk of decline.

A major obstacle to DEC’s performance is the long delay in drafting a Biodiversity Conservation Act, to replace the existing Wildlife Conservation Act 1950. DEC has pursued updated legislation for over 20 years.

The current legislation restricts DEC’s ability to effectively conserve threatened species; existing protection measures are largely inadequate, and DEC does not have the power to access threatened species on private property to implement much-needed conservation action.

The report found that multi-species approaches to conservation can be effective in dealing with the growing number of threatened species.

“DEC is undertaking a number of multi-species approaches. For example, the Western Shield program has improved the status of several native mammals,” Mr Murphy said.

“DEC is also acquiring land to secure species habitat, but less than half the nationally agreed target has been reserved in WA.”

The Auditor General’s report found a number of other areas for improvement, particularly:

* DEC cannot demonstrate that all of its threatened species conservation activities are effective.
* DEC has not identified habitat critical to the survival of all threatened species.
* State and Commonwealth threatened species lists are not aligned and 190 WA species do not receive protection from the Commonwealth Government.

“Increasing numbers of threatened species and the size of WA present a significant challenge for DEC,” Mr Murphy said.

“Achieving the right balance between programs which benefit large numbers of species at once, with those targeted at individual species’ needs, will be critical.”