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Should we move Tasmanian Devils back to the mainland?

In almost all parts of the world our environment is under siege and we are losing the battle to save many species from extinction. The most common threats behind this unfolding catastrophe are habitat…

This Tasmanian Devil needs a holiday. How about the mainland? Flickr/sillypucci

In almost all parts of the world our environment is under siege and we are losing the battle to save many species from extinction. The most common threats behind this unfolding catastrophe are habitat loss and modification, invasive species, and climate change. What can we do?

Usually we focus on treating the symptoms — planting trees or shooting pest animals — but these treatments often fail. Perhaps we need radical new solutions for fixing broken ecosystems.

One such solution could be introducing (or reintroducing) species to ecosystems. There is now a serious and broad-based proposal to release Tasmanian Devils into the wild at Wilsons Promontory in Victoria, saving devils from extinction in Tasmania, and restoring damaged ecosystems on the mainland.

What is rewilding?

We can look at the Tasmanian Devil proposal in terms of an ecological concept known as rewilding. In essence, rewilding seeks to restore ecological function to habitats by introducing or reintroducing species that could perform vital roles.

Perhaps the best example comes from Yellowstone National Park in the US, where wolves were returned after a 70-year absence. Wolves are crucial to Yellowstone’s ecosystems. Without them herbivores like deer and moose flourish, and prevent trees from producing saplings (see video below).

We must return predators and their functions back into landscapes

In Australia, the Tasmanian Devil is an ideal candidate for reintroduction to the mainland.

Saving devils

Tasmanian Devils used to inhabit mainland Australia. When exactly they went extinct on the mainland is uncertain, with dates ranging from 5,000 to as recent as 500 years ago. But in 1881 Frederick McCoy, the first director of the National Museum, noted that Tasmanian Devils (or perhaps that should be “mainland” devils) are very common in the most recent cave deposits in Victoria. These fossils are identical to living devils in Tasmania.

Why they became extinct is more mysterious. Various theories have attributed blame to climate change, over-hunting by Aboriginal Australians, and dingoes.

But whatever the cause, current conditions at Wilson’s Promontory closely resemble those in Tasmania, and have likely remained unchanged for thousands of years, with no dingoes and plenty of prey. So we can be sure that the devils would fit in.

But why move them now?

One excellent reason is that there is a genuine risk that devils could become extinct in the wild by 2025, as a result of devil facial tumour disease (DFTD). A mainland population would act as a large, wild insurance population, outside of Tasmania where DFTD is present.

How would the mainland benefit?

So we know Tasmanian Devils have been on the mainland before, and that moving them might help save the species from extinction. But what could devils offer the mainland?

One of the biggest benefits devils could offer is in the control of the red foxes, feral cats and overabundant herbivores (such as wombats, rabbits and wallabies). Evidence for this comes from Tasmania. Following the decline of devils due to DFTD, species such as the feral cat have been increasing. This in turn is associated with a halving in population size of a smaller, native predator, the Eastern Quoll (once present, but now extinct in Victoria).

Some have also suggested that the reason foxes have only recently established themselves in Tasmania is not solely due to humans introducing them, but because devils declined around the same time. Prior to DFTD, devils may have been acting as a first line of defence against foxes by killing their cubs.

Currently we spend a lot of money managing foxes on mainland Australia through baiting programs. But are we going to do this forever? Devils may provide a 24-7 predator control service, free of charge.

Focusing on foxes also ignores the fact that there is no effective control of probably Australia’s most damaging feral animal, cats. As noted above, devils are capable of limiting cats too.

Another issue at Wilson’s promontory is an over-abundance of herbivores including wombats, swamp wallabies, rabbits, kangaroos and hog deer. All of these increased rapidly following the removal of dingoes in the 1940s.

In high numbers these herbivores can radically alter habitats, making them unsuitable for other species. We can shoot herbivores to keep them down, or we could introduce a natural predator such as Tasmanian Devils.

What’s next?

Parks Victoria and an ambitious multi-institutional research hub, the Wildlife Biodiversity Co-operative Research Centre are behind the new proposal to move devils to Wilson’s Promontory. Planning is underway for a comprehensive proposal to the Victorian and Tasmanian governments, and thorough consultation with the public.

With this in mind I urge our leaders to be bold and act now. There are always risks with moving species, but not taking calculated risks to conserve our wildlife is perhaps even worse. A devil reintroduction should be viewed as a positive and strategic national decision, and one for which future generations will thank us.

It is not often we can achieve win-wins in conservation, but helping prevent the extinction of the Tasmanian devil by re-establishing a mainland population, and restoring desperately needed ecosystem function to habitats, may just be the best conservation win-win waiting to happen.

Less than 15,000 years ago Wilsons Promontory and Tasmania were connected by land. Is now the time to help bring back devils to the Prom? Steve Bennett/Wikimedia Commons

Join the conversation

45 Comments sorted by

  1. Bob Turner

    logged in via email @hotmail.com

    Bring the Tassie Tiger over at the same time, any indications they used to inhabit the mainland too?

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    1. Mike Swinbourne

      logged in via Facebook

      In reply to Bob Turner

      Bob

      The thylacine used to be widespread on the mainland, but it's decline coincided with the arrival of the dingo. The two events may be related (and many think so), or may be not.

      Small problem with bringing them back..............

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    2. Euan Ritchie

      Senior Lecturer in Ecology, Centre for Integrative Ecology, School of Life & Environmental Sciences at Deakin University

      In reply to Bob Turner

      The thylacine went right up to Northern Australia. There is even cave paintings at Kakadu.

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    3. Don Gibbons

      Clerk

      In reply to Euan Ritchie

      Hi Euan

      Thanks for the article. I understand there is fossil evidence for Thylacinus cynocephalus in New Guinea as well. As for Devil rewilding on the mainland, any shot, even a long shot, is worth preserving the largest marsupial carnivore left after such a long retreat...first the borhyaenoids in South America, then the thylaceolenids, and finally the thylacinids have vanished. If we can introduce the dingo, cat and fox, surely we can try and reintroduce the Devil to the bulk of the continent where it evolved, and became extinct only a geologic instant ago.

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  2. Edward Cannella

    Zoologist

    Any thought given to the likelihood of Tasmanian Devils feasting on an already depleted native fauna? It has been many thousands of years since this species existed on the mainland. Why create more problems? There is nothing wrong keeping them in tightly controlled sanctuaries located on the mainland if they are specifically designed for their conservation and for keeping them in. But to release them into mainland habitats beggars belief. It really is an issue of why we wish to conserve and protect…

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    1. Euan Ritchie

      Senior Lecturer in Ecology, Centre for Integrative Ecology, School of Life & Environmental Sciences at Deakin University

      In reply to Edward Cannella

      There are risks with any reintroduction, but it's all about net benefit from the prey's perspective. Devils will exclude/kill cats and foxes, which leave devils for dead in the killing stakes, so native animals are better off with devils overall, even if they sometimes might get eaten by one. Another thing to bear in mind is that devils will mostly target abundant prey (i.e. rabbits, wombats and swamp wallabies)

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    2. Edward Cannella

      Zoologist

      In reply to Euan Ritchie

      Thank you for your response Euan. I would need to be convinced through some further research into reintroduction of top order predators. From my understanding, any introduced predators would have to be removed or at least driven to unsustainable numbers and the native fauna allowed to recuperate before you could introduce the impact of a medium sized/top order predator such as the TDevil. The issue is that the faunal assemblages have already been altered by the impact of introduced herbivores and predators (and other anthropogenic impacts) so the introduction of another predator (regardless of it being native or not) may not lead to desirable outcomes. More research is the answer...........

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    3. Account Deleted

      logged in via email @drdrb.net

      In reply to Edward Cannella

      Wouldn't it be the case that the native fauna would probably still possess evolved instincts recognising devils as predators, while introduced ferals (e.g. rabbits) would lack these?

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    4. Edward Cannella

      Zoologist

      In reply to Account Deleted

      Hi James, I think that would be assuming way too much about the cognitive abilities of the animals. They certainly recognise predators much like we recognise danger irrespective of the species.

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    5. Account Deleted

      logged in via email @drdrb.net

      In reply to Edward Cannella

      While I'm not a biologist or similar, I seem to recall various experiments showing infant animals had instinctive fears of snakes and hawks, even if they had never encountered them before.
      Can't one assume that past predation by tassie devils/tigers would have shaped the behaviours of prey animals through natural selection? And that behaviour would persist even after the predators were removed, given the removal happened quite recently in evolutionary time?

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    6. Edward Cannella

      Zoologist

      In reply to Account Deleted

      I understand your premise James. What I was trying to suggest is that introduced herbivores such as rabbits would have similar reactions to any predators regardless of what predator species may be around. From memory (about 27 years ago when I was studying), those types of experiments you referred to also found the same reaction when young animals were confronted by predators that they would never come across in the wild. I am stretching my knowledge on this subject but I think it is unlikely that mainland native animals have a genetic memory to a "flight" response when confronted specifically by TDevil. It would more likely be just a recognition that a something may be after them so they take flight.

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  3. Mike Swinbourne

    logged in via Facebook

    Euan

    Thank you for this interesting and thought provoking article.

    I have been a strong advocate of restoring apex predators and the trophic structure as a means of ecosystem management, and have read lots of work in this regard on dingoes. The issue of wolves in Yellowstone NP is a well-known example and lends support to the concept.

    I had not seen that paper on the effect of devil decline on mesopredators, and will read it with interest. I would also be interested in reading more about any work that has been done in regard to the proposal to introduce devils to the mainland. Could you point me to any studies which have been undertaken to date, or what is the status of the research?

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    1. Sebastian Poeckes

      Retired

      In reply to Mike Swinbourne

      There was an earlier, unsuccessful, attempt to establish devils and Tassie tigers on Wilson's Prom, in about 1910. I think it was sponsored by the Vict. Field Nats. or a predecessor organisation.
      For years afterward there were reports of "wolves" taking sheep, etc., as far west as Wonthaggi. Eventually all the introduced creatures died out.

      The Melbourne Museum also has a couple of road-kill carcasses of devils found in Victoria over a period of years. For some time there were reports of a small population of introduced devils hanging on near Harcourt. But I think this group have died out also.

      So, it may not be easy to successfully establish a population of devils on the mainland unless they are very carefully monitored.

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    2. Greg North

      Retired Engineer

      In reply to Sebastian Poeckes

      I lived in the Latrobe Valley for a bit back a few years and we'd regularly take the back unmade roads up into the Strezleckis and along what is called the Ridge road ( generally north of the Prom ).
      One particular time I saw a dark animal crossing the road some distance ahead, it being pretty big and cat like in movement and there had been the odd stories of panthers or jaguar like cats in the area, the animal I saw big enough to have been something like that and far too big for a feral cat.
      I'd not heard of wolves being about though.

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  4. John Newlands

    tree changer

    In my opinion devils are no match in speed or cunning for foxes, dogs or cats, feral or otherwise. Therefore Bass Strait may have helped them survive as long as they have. You sometimes see rebound roadkill where a devil feeding on say a skittled wallaby itself gets skittled by another car. The secret to preserving devils may be to remove all those factors. However enclosure may worsen the inbreeding problem.

    Therefore I'd breed healthy devils in small mainland sanctuaries and periodically return to some to larger refuges like Maria Island. We'll have to do that forever.

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    1. Henry Verberne

      Once in the fossil fuel industry but now free to speak up

      In reply to John Newlands

      I like the idea of breeding devils which are currently free from facial tumour disease in small mainland sanctuaries. (maybe within Wilson's prom to help determine its long term suitability as a permanent site). If devils were just released at the prom they may not survive. A controlled breeding program will hopefully insure there is a disease-free population that could be used at some future time to replenish the Tassie devil population.

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    2. Euan Ritchie

      Senior Lecturer in Ecology, Centre for Integrative Ecology, School of Life & Environmental Sciences at Deakin University

      In reply to John Newlands

      The devils in Tas already coexist with cats, wild or farm dogs and more recently foxes. If devils were reintroduced what'd work best is to knock cats and foxes right down first, then introduce devils and let their populations grow. They should then have the advantage over cats and foxes, with these species not being able to bounce back.

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    3. Steve Phillips

      Nurse Practitioner

      In reply to John Newlands

      Foxes use sets for their young, this leaves them vunerable to TA predation. Cat's litters are even more vunerable. Also cats have no stamina, the aboriginal ladies in the centre hunt them by simply flushing one out from its lair usually under as bush and then walking after it, wearing it down till they can just walk up and dong it on the head. Devils have a lot of stamina and are more than a match for a cat one on one.
      Id rather see TAs than scabby ferals anyday.

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  5. Fred Pribac

    logged in via email @internode.on.net

    Re-introduction is an interesting concept.

    It seems to have worked in Yellowstone where the lack of the apex predator had devastating consequences. For Wilsons Prom, however, which presumably has feral cats, foxes and maybe even dogs now occupying apex predator niches the results might be quite different and perhaps not so beneficial.

    Your article suggests that you expect the introduction of devils to inhibit fox and cat populations but is that really such a given? Could there be some hysteresis…

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  6. Greg North

    Retired Engineer

    They have been doing some work on determining what is causing that DFTD and last time I read something, they were claiming to be close to success and yet I've not heard anything since.
    At one stage I think they had even isolated in a compound what they considered were DFTD free devils to no avail and put occurrence in the compound down to transgressing of devils from outside from what I remember.
    Trying to develop a healthy colony on the mainland would not do too much harm I imagine but perhaps they ought to try and have a few well separated groups and monitor closely re the DFTD to see if any developed, especially if they do not yet know the origin of that disease.

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  7. Chris Owens

    Professional

    I'm all for looking at some radical solutions. Sitting on our hands is not working. Leave the bureaucrats out of it though. If we leave it to then they will form a committee and pontificate for a decade or two by which time we will be down to a handful of hardy species. Some farmers also have disproportionate influence on the debate.

    A friend's neighbour shot 17 foxes on his farm over a period of two weeks. The farm has pockets of bush and few native species can survive these fox densities. However successful trapping and shooting programs are, they run their course then fox and cat numbers quickly rebound. Native species evolved with devils and I suspect devils will eventually keep a lid on cat and fox numbers.

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    1. Greg North

      Retired Engineer

      In reply to Chris Owens

      I was reading a short article in the weekend paper Chris re feral pigs being out of control in northern Queensland too and when you look at ferals generally all around Australia, there is a huge problem for graziers and the natives, flora and fauna.
      The pigs and huge monsters they can be too apparently are decimating turtle egg nests on the Cape and eventually it'll be curtains for turtles too.
      I reckon there is a potential shooters tourist market there for the taking with governments approvals.

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    2. Steve Phillips

      Nurse Practitioner

      In reply to Greg North

      Theres been a big discussion and the general consensus of the readers is, it is better that the ferals take over than even one be shot by a 'recreational' shooter.
      So the turtles are stuffed Im afraid.

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  8. Chris Strudwick

    Human

    I for one would strongly support an initiative like this. The devils might need some initial help, or might fail to thrive at all, but there doesn't seem to be a lot to lose from trying. Fenced sanctuaries on the mainland are also worth some effort, it needn't be one option or the other. If it works out it might create better conditions for a future quoll reintroduction. Devils will almost certainly change things at the 'Prom' but the net result stands a good chance of being beneficial. Devils were at least locally indigenous at one time, so I don't see a killer plague of devils in the offing.

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    1. Sebastian Poeckes

      Retired

      In reply to Chris Strudwick

      If previous attempts at re-introduction have failed, what are the chances that a new attempt would be any more successful?

      Not good odds.

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    2. Greg North

      Retired Engineer

      In reply to Sebastian Poeckes

      If the previous attempt was a century ago Sebastion, hopefully a lot more by way of resources could make a difference these days.

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    3. Luke Barrett

      Ecologist at University of Melbourne

      In reply to Greg North

      Resources aside, we also know a lot more about inbreeding depression. It'd be crucial to bring in new tumor-free individuals from Tassie every now and then to get some new genetic variation.

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    4. Luke Barrett

      Ecologist at University of Melbourne

      In reply to Luke Barrett

      But then again, their genetic diversity is so low already (hence the spread of tumors) that it might not matter. Maybe all we can do is try to keep them ticking over.

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  9. Kerry Williamson

    Retired

    In reply to Fred Pribac
    I know of Tasmanian Devil remains and the extremely chewed up bone remains of their meals from caves near Margaret River in WA and just south of the Queensland border in NSW - both a long way north of their current Tasmanian distribution.

    This would suggest some ability to deal with at least the temperature aspects the climate changes to come but the effects of climate extremes and rainfall changes to comes are anyone's guess.

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  10. Steve Phillips

    Nurse Practitioner

    I agree as long as it can be proven they were once part of the local ecology.
    Control of vermin or overpopulated specis is better done naturally like a Tassie Devil eating the young than a quick inhumane death by some shooter.

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  11. John Newlands

    tree changer

    I think people are making two wrong assumptions
    1) devils bring down fast prey
    I believe they mainly eat carrion since the Tas bush has several wallabies per hectare many of which die of natural causes.
    2) devils will eat the young of pest predators
    Other way round. A fox would almost certainly eat devil joeys if the burrow was unattended by the mother.

    A neighbour insists that the facial tumour was triggered by the use of 1080 to kill possums that ate seedlings in replanted areas. Supposedly 1080 was discontinued some years ago. I wonder if some DFTD resistant animals are now emerging perhaps not in enough numbers to re-establish a sustainable population.

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    1. Greg North

      Retired Engineer

      In reply to John Newlands

      There may not be the potential for devils to work on feral animals as you say John but the primary reason is to see if other colonies can be established to help their survival, helping with the control of feral animals being a bonus if it occurs.
      According to devilark, DFTD is thought to be occurring because of low immune genes, possibly making them more susceptible to diseases introduced by dogs even but no mention of 1080.
      http://www.devilark.com.au/research

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    2. Steve Phillips

      Nurse Practitioner

      In reply to John Newlands

      Young rabbits, foxes and kittens are not fast prey.
      They will attack, kill and eat adult foxes in the set.
      I wonder though if the habitats on the mainland are suited to the Devils?

      It is a strange theory, is your neighbor a biologist or a research scientist? 1080 has been used over the whole of Australia for many years and is derived from a naturally occuring substance. Why have no other native or non-native animals succumbed?

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    3. Geoff Clark

      Senior Lecturer at University of Tasmania, School of Architecture and Design

      In reply to Steve Phillips

      I have to concur with the speculation that 1080 is to blame I am afraid. Yes, it is speculation, but the coincident arrival of 1080 and DFTD, given the Devil's feeding and socialising habits, and otherwise long and illustrious lineage, is just too extraordinary to ignore. Browsing animals are slaughtered in vast numbers, using 1080, in order to protect the (sustainable) forest industry. This provides a food supply for the devils unmatched by any other in the state for volume and convenience.

      Nope…

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    4. Paul Wittwer

      Orchardist

      In reply to John Newlands

      In the book, Frog Call, by Greg French, a couple of nasty chemicals were mentioned in relation to Tasmania. One was used in fish breeding and was a known carcinogen, no longer used.
      The other was a weedicide, still used in the forestry industry.
      Unfortunately I no longer have the book so can't give you the names but I would put my money on the widespread use of weedicides by forestry before blaming 1080.

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    5. Roger Simpson

      logged in via LinkedIn

      In reply to Geoff Clark

      "We continually generate these disasters and then pat ourselves on the back at the wonderful scientific theories and latest cutting edge technologies and approaches that may herald their minor mitigation...or simply result in the next catastrophe - Science!"

      Good observation Geoff!

      There has been some conversation for many years in Tasmania re the possible link with forestry but no evidence has been found. I have worked with some of the people involved with the project and they would not disregard such evidence if some was found. The "circumstantial" link between the rise of forestry and chemical use and the dying out of devils remains though.

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    6. Luke Barrett

      Ecologist at University of Melbourne

      In reply to Geoff Clark

      Unfortunately, describing a phenomenon in a holistic rather than piecemeal manner doesn't help you understand what's actually happening. You're describing what the black box is doing, but you don't know how or why. Science used to be much more holistic, and it led to some spectacular misunderstandings about the workings of biology and the universe. We've since learned that coincidences shouldn't be trusted, but that they can present a good starting point for more rigorous research.

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    7. Luke Barrett

      Ecologist at University of Melbourne

      In reply to Luke Barrett

      However, if you simply mean that we should be more careful about releasing new chemicals into the environment, and consider their potential impacts at the level of the ecosystem as well as the cell, then I'd agree with you.

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  12. Gary Fry

    Director at OzGREEN

    "There are always risks with moving species, but not taking calculated risks to conserve our wildlife is perhaps even worse."
    A well considered article, Euan. This sentence in the second last paragraph is key. We should consider such a re-introduction as you have proposed. Like it or not, as we have fragmented habitats and introduced feral species, we have forced ourselves into having to make decisions around wildlife management. Sometimes those decisions may need to be quite bold. At the very least, considered proposals such as this require serious consideration.

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  13. Julie Fechner

    Retired (Grumpy old woman)

    The importance of top order predators is a growing area of research but there are still many things we do not know, so we must be careful in identifying species that are true top order predators. As yet it is unclear how the thylacine and the devil interacted prior to the thylacine going extinct, and if perhaps it was this interaction that prevented the development of the DFTD in the past. The presence of the thylacine may have impacted on devil essentially reducing their numbers, or behaviour…

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  14. Alex Dudley

    logged in via LinkedIn

    The decline of devils in Tasmania seems to be linked with a rise in cat numbers, which in turn, has lead to a catastrophic decline in Eastern Quolls. This is almost certainly because devils can find and predate on kittens; how devils will deal with foxes remains to be seen, as fox numbers are still low in Tasmania. However, it has been suggested that previous attempts to introduce foxes to Tasmania were thwarted by the presence of devils. Even just as an experiment, I would love to see devils reintroduced to the mainland.

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  15. Ian Gunn

    Veterinarianr; Faculty of Medicine, Nursing and Health Services; Project Director of AGSRCA at Monash University

    Totally support the concept and it would be a positive move for the local environment and hopefully the Devils. The problem is how do we ensure that the Devils are contained within the Prom Park? Thanks Euan.

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