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Tasmanian Devils are picky eaters — and they may just have broken the laws of scavenging

Credit: Mathias Appel, Flickr.

As the largest carnivorous marsupial in the world, the Tasmanian devil is strictly carnivorous, hunting frogs, birds, fish, and insects. But most of their meals actually consist of carrion. Yet Tasmanian Devils aren’t your typical scavengers that will devour anything they get their teeth on. Much to everyone’s surprise, researchers in Australia found that the devils have very specific tastes and dietary preferences, which furthermore can vary from individual to individual. That’s rather unheard of for scavengers but the rowdy devils are not ones to play by the rules.

“It’s a scavenger’s job to just be a generalist and take whatever it can find,” says Tracey Rogers, senior author of the study and a Professor at the School of Biology, Earth and Environmental Studies at the University of New South Wales.

“But we’ve found that most Tasmanian devils are actually picky and selective eaters—they’ve broken the laws of scavenging.”

Scavengers, also called carrion-feeders, are animals that feed partly or wholly on the bodies of dead animals. Vultures, crows, and hyenas are among the most famous scavengers in the animal kingdom, playing an important role in the food web by keeping the ecosystem free of carrion and recycling organic matter into ecosystems as nutrients.

One of the reasons scavengers have a place in the food web, somewhere between prey and predator, is that they are very flexible about what they eat. The American crow will eat mice, eggs, seeds, and nuts, for instance, making them highly adapted to virtually any environment, be it the wild or sprawling urban areas.

Part scavengers, Tasmanian devils have always been thought to eat just about anything — but it turns out they’re pickier than a toddler.

Anna Lewis, the lead author of the study and Ph.D. candidate at UNSW Science, laid traps in the island of Tasmania for a week at a time, catching around 10 devils per day. In total, they captured 71 individuals across seven different sites, from which they removed small whisker samples before releasing them back to the wild. Each bristle is embedded with isotopes from the food the devils ate in the past, thus revealing their diets.

Just around one in ten devils had a generalist diet, consisting of whatever food was available in their habitats. Most devils, however, chose to eat their favorite foods, such as wallabies, possums, and rosellas, and turn up their noses at unappealing carrion.

The heaviest devils also proved to be the pickiest eaters. This could mean either that size is a driving factor in their food choices or, alternatively, specializing in certain types of carrion helps them gain weight.

What’s more, there was a great deal of variation among individuals. Just like humans, individual devils have their favorite meals.

“We were surprised the devils didn’t want to all eat the same thing,” said Lewis in a statement.

“Most of them just decided, ‘No, this is my favorite food.'”

Lewis and colleagues go on to add in their study published in Ecology and Evolution that this behavior seems to be devil-specific. Sure, there may be other scavengers that are non-generalists, but we’ve yet to find others.

Other scavengers can’t afford the luxury of saying ‘no thanks!’ to whatever carrion comes their way. Vultures in Africa, for instance, have to compete with myriad other predators and scavengers for food. Once they smell carrion, they’ll swoop right in, no questions asked. Check, please!

But in Tasmania, Tasmanian devils are virtually at the top of the food chain, with little competition for carcasses. “Their main competition is just with each other,” said Professor Rogers.

Arcturus, one of the devils from the study, named after one of the brightest stars in the sky, likes to eat pademelon and wallabies. But every once in a while, he decides to go for something different, indulging in a snake or two.

“Tasmanian devils are these really cool scavengers that are doing something completely different to every other scavenger in the world,” says Ms. Lewis.

“We’re lucky to have them here in Australia,” she added, hoping to keep it that way. The numbers of Tasmanian devils have plummeted since the 1990s due to a variety of reasons, chief among them a serious epidemic called Devil Facial Tumor Disease (DFTD).

It’s only one of three transmissible cancers known to man (the other being in dogs and shellfish), but also one of the most unforgiving, having an almost 100% kill rate. Today, the population of the iconic Australian marsupial is down 90% and many researchers fear the devil may be doomed unless something is done about it — and fast.

Until scientists develop a viable treatment or vaccine for DFTD, conservation groups have focused on minimizing interactions between populations, even opting for capturing some devils until it’s safe to release them back into the wild. Dietary studies such as these may help inform conservationists what kind of diets the devils respond best to in order to maximize their odds of survival in captivity.

“From a conservation perspective, the findings could help us work out if we’re feeding devils the appropriate thing in captivity,” says Ms Lewis.

“At the moment, there’s a long list of foods that devils can eat, but it’s not specific in how often they eat all those foods or whether most only focus on a few different food types.”

Tasmanian devils return to mainland Australia for the first time in 3,000 years

 A Tasmanian devil at Aussie Ark. Credit: Aussie Ark.

Around 3,000 years ago, Tasmanian devils were driven out from mainland Australia by dingoes introduced by Sulawesi hunter-gatherers. Fortunately, dingoes never made it to the island of Tasmania, the namesake of the devils, which helped the aggressive scavengers avoid extinction. But recent challenges such as habitat loss and the spread of one of the only known contagious cancers in the world are casting doubt on the fate of the iconic mammal.

With just 25,000 devils left in the wild in Tasmania, today’s announcement of their reintroduction to the Australian mainland marks a historic moment.

“In 100 years, we are going to be looking back at this day as the day that set in motion the ecological restoration of an entire country,” said Tim Faulkner, president of Aussie Ark. “Not only is this the reintroduction of one of Australia’s beloved animals, but of an animal that will engineer the entire environment around it, restoring and rebalancing our forest ecology after centuries of devastation from introduced foxes and cats and other invasive predators. Because of this reintroduction and all of the hard work leading up to it, someday we will see Tasmanian devils living throughout the great eastern forests as they did 3,000 years ago.”

Back home

Aussie Ark, an Australian non-profit that aims to protect the country’s endangered species, has been breeding Tasmanian devils (Sarcophilus harrisii) in captivity since 2011. The organization has so far been responsible for raising nearly 400 devils in a habitat that fosters their sense of independence and all the necessary skills they require to survive in the wild.

In partnership with Global Wildlife Conservation and WildArk, Aussie Ark released 11 devils into a 400-hectare wildlife sanctuary on Barrington Tops. The individuals were selected so that they can mate with one another without any inbreeding, and biologists at the wildlife sanctuary hope that this initial small population will soon grow in numbers.

As apex predators and the world’s largest carnivorous marsupials, the devils will help balance the ecosystem by controlling invasive species such as feral cats and foxes that threaten endemic species.

“The re-introduction of devils to mainland Australia is a game-changer for conservation in this country, not only building a robust, genetically healthy population outside of Tasmania, but also paving the way for future introductions that the Aussie Ark team are already mapping out,” said Mark Hutchinson, co-founder of WildArk. “Having partnered with Aussie Ark and GWC on the Koala Comeback Campaign after the bushfires this year, we’ve witnessed first-hand their commitment to ecological restoration in Eastern Australia and we couldn’t be prouder to now support the Devil Comeback. The groundwork is being laid for a broad, nationwide effort to rewild Australia and help our little critters find their niche again.”

In recent years, life hasn’t been easy for the Tasmanian devils. In 1996, the first case of devil facial tumor disease (DFTD) was reported by scientists. It’s only one of three transmissible cancers known to man (the other being in dogs and shellfish), but also one of the most unforgiving, having an almost 100% kill rate. Today, wild populations of the iconic Australian marsupial are down 90% and many researchers fear the devil may be doomed unless something is done about it — and fast.

To make matters worse, devastating fires across the continent earlier this year destroyed 72,000 square miles of forest and claimed the lives of nearly 3 billion wildlife.

“The fires earlier this year were absolutely devastating and threatened to rob us of our hope,” Faulkner said. “This is our response to that threat of despair: come what may, ultimately we will not be deterred in our efforts to put an end to extinction and to rewild Australia.”

Their introduction to mainland Australia might help swell their numbers, as well as bring them into new habitats away from the dreaded DFTD’s reach.

Aussie Ark plans on introducing 40 devils to the wild over the next two years. Each animal is fitted with radio collars that monitor their location and movements. Additionally, camera traps in key locations will help conservation scientists keep a close eye on the devils.

A tumor from the transmissible cancer afflicting Tasmanian devils. Image credits: Maximilian Stammnitz.

Scientists learn how horrible face cancer spreads among Tasmanian devils

A tumor from the transmissible cancer afflicting Tasmanian devils. Image credits: Maximilian Stammnitz.

A tumor from the transmissible cancer afflicting Tasmanian devils. Image credits: Maximilian Stammnitz.

There are more than 200 types of cancers that afflict humans, with lung, breast, prostate, and bowel cancer accounting for more than half of the cases. More than 1 in 3 people will develop some form of cancer during their lifetimes. Yes, cancer is the stuff of nightmares but imagine what it would be like if it were transmissible like an infectious disease. For the Tasmanian devil, this nightmare is part of their everyday reality.

In 1996, the first case of devil facial tumor disease (DFTD) was reported by scientists. It’s only one of three transmissible cancers known to man (the other being in dogs and shellfish), but also one of the most unforgiving having an almost 100% kill rate. Today, the population of the iconic Australian marsupial is down 90% and many researchers fear the devil may be doomed for unless something is done about it — and fast. Now, an international team of researchers has reported finding the molecular mechanisms responsible for the transmission of cancer among the marsupials, with the potential of a new therapeutic pathway that might save the species from obliteration.

Previous investigations showed that cancer is transmitted from one Tasmanian devil to the other by bites. This certainly doesn’t bode well for a species which is notorious for its highly aggressive behavior. When scientists examined tumor samples from different individuals, they noticed that all the cells were genetically identical, presumably deriving from a single cell of origin.

Researchers at the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences and the Vienna University of Veterinary Medicine performed experiments on cell tumors from Tasmanian devils. Their investigation revealed that receptor molecules on the surface of the cancer cells (ERBB receptors) have a hugely increased activity compared to samples taken from other creature (i.e. humans). This high activity triggers a biochemical reaction within the cells, thereby activating STAT3 proteins — transcription factors that alter the cell’s genetic program. The reprogrammed cells have fewer molecules that serve as identification for the immune system, while at the same time proliferation is accelerated and factors for metastasis are produced.

“Our experiments show for the first time that the excessive activation of ERBB receptors and STAT3 proteins play a key role in the transmissibility of the Tasmanian devil´s facial tumor,” Lindsay Kosack, a researcher at CeMM and co-first author, said in a statement. “Above that, we showed in further experiments that the inhibition of ERBB receptors with a drug can selectively kill the cancer cells. This could play an important role for the treatment of the disease, before the Tasmanian devil becomes extinct.”

Schematic of molecular mechanism responsible for the transmissibility of the Tasmanian devil´s facial tumor. Credit: Cancer Cell.

Schematic of molecular mechanism responsible for the transmissibility of the Tasmanian devil´s facial tumor. Credit: Cancer Cell.

What’s intriguing is that 99.1% of the devil’s STAT3 are identical to the human variant and many of the genes activated by the protein are also active in human cancers. Thus, this rare phenomenon might offer new exciting opportunities to study cancer metastases. But before you get too worried, the researchers assure us that a similarly transmissible cancer in humans is almost impossible.

“Apart from the molecular mechanisms that would need to evolve are humans genetically much more diverse and resistant than the isolated population of the Tasmanian devils. The aggressive biting behavior of the animals also seems to play an important role in tumor transmission. Nevertheless, a better molecular understanding of this rare disease can provide valuable insights on fundamental biological mechanisms of cancer development,” Andreas Bergthaler, Principal Investigator at CeMM and first author of the new study, said in a statement.

Fortunately, there are people working on multiple fronts to save the devils. Besides this newly identified molecular mechanism, researchers previously found that the two types of cancer known to affect devils delete genes responsible for cancer recognition in the immune system. This is achieved with the help of molecules called receptor tyrosine kinases. The good news is that there are already drugs developed for humans that target these molecules, which seem to halt the growth of Tasmanian cancer cells in the lab.

Another promising study found that although DFTD kills most of the devils it comes across, those that survive seem to have genetic qualities that protect them. In time, researchers hope that new devil populations become immune to transmissible cancer. However, fragile populations with few members need to be protected from other threats such as loss of habitat and climate change.

The findings appeared in the journal Cancer Cell

Immunotherapy brings new hope for fading Tasmanian devils

An international study carried out over six years might spark new hope for Tasmanian devils threatened by the contagious devil facial tumour disease (DFTD).

Image via Wiki Commons.

Contagious cancer — those are two words you never want to hear, yet it’s what Tasmanian devils have been fighting with for years. In 1996, the first case of devil facial tumor disease was reported by scientists. It’s only one of three transmissible cancers known to man, but also one of the most unforgiving, killing almost all of its victims. Over 20 years later, the situation of the species is looking pretty grim. The carnivorous animal has suffered one of the steepest population declines ever to be documented. In just 15 years, it went from being a common animal to the brink of extinction and things are barely looking up. Recently, the devils impressively started developing resistance to this horrific disease, but it’s still an uphill battle for them — now, the little creatures might get some help from scientists.

The new research led by researchers from University of Tasmania’s Menzies Institute for Medical Research was a step-by-step laborious process, taking them closer and closer to the breakthrough. Now, Professor Greg Woods, the leader of the DFTD team at Menzies, says they’ve finally had the ‘Aha!’ moment.

“This is almost a Eureka moment for us because it’s the first time we can say for sure that it was the immunotherapy that was making the tumour shrink,” Professor Woods said.

Immunotherapy, also called biologic therapy, is a type of cancer treatment designed to boost the body’s natural defenses to fight cancer. The devils themselves inspired researchers to opt for this approach — by developing a surprising immunity response. The first such response was observed in 2009, but at the time, biologists didn’t really know what to make of it. The first time they observed it, the tumors grew, shrank, then grew again and ultimately killed the little devil. But before that, the devil managed to produce some offspring. In other words, it passed on its genes. DFTD won again, but this was just the first round. In the next generation, one more succumbed but four Tasmanian devils survived. By now, researchers knew they were on to something. When they tested the surviving devils, they found some antibodies that were not present either in animals that did not have DFTD or had normally progressing DFTD. It’s unclear by now if the resistance is passing on genetically or if there is some other mechanism here, but at the moment, a whopping 10% of that specific population now seems to be immune to cancer. This was an incredibly fast adaptation to a huge threat.

But developing an immunotherapy strategy is no easy feat. The first step in an effective understanding of the Tasmanian devils’ immune system, which is painstakingly hard lab work. Then, you have to develop a vaccine to prevent the development of DFTD in clean devils and potentially generate immunotherapy to cure devils suffering from established DFTD. They’re not quite there yet, but they’ve seen a good glimpse of how it can work.

“Our research shows that a DFTD vaccine is feasible. We are focusing our efforts on developing strategies to improve the devils’ response to immunisation,” Dr Tovar said.

Dr Cesar Tovar is the lead author on the latest paper, and he too said results are very encouraging. It is possible to trigger the devil’s immune system to recognize and destroy established DFTD tumours, and we’re slowly getting there. Hopefully, it won’t be too late.

Journal Reference: C Tovar, RJ Pye, A Kreiss, Y Cheng, GK Brown, JM Darby, RC. Malley, HV Siddle, K Skjodt, J Kaufman, A Silva, A Baz Morelli, AT Papenfuss, LM Corcoran, JM Murphy, MJ Pearse, K Belov, AB Lyons and GM. Woods (2017). “Regression of devil facial tumour disease following immunotherapy in immunised Tasmanian devils.” Scientific Reports

Tasmanian devils developing resistance to horrendous infectious face cancer

Tasmanian devils are fighting against one of the most devastating diseases ever seen on the face of the planet: a virulent type of infectious cancer. But there may yet be hope for the little devils, as researchers have observed they’re developing a surprisingly strong resistance to the disease.

Hang in there, little fellow. Photo by Wayne McLean.

Infectious cancer should simply not happen. It’s like taking the worst two things and zapping them together to create the ultimate killing machine – and what a machine this has been. Devil facial tumor disease (DFTD) is an aggressive non-viral transmissible parasitic cancer which was first observed in 1996 in Australia. Since then, 70% of the population has been wiped off and in many areas, fatality rates were 100%. For many, the species was already condemned and several contingency plans were developed, to save the devils in sanctuaries and then release them into the wild.

But these are no common critters – they’re Tasmanian devils, and if you’d expect a fight from any species, it’s the Tasmanian devils. University of Tasmania researchers, led by biologist Rodrigo Hamede, found a small population in Cradle Mountain national park, Tasmania, which seems to have developed an immune response.

“At some stage we realised that some animals that I was counting with early stages of DFTD, when I was coming back three months later they didn’t have the tumours any more,” Hamede told Guardian Australia.

An immune response was first observed in 2009, but at the time, biologists didn’t really know what to make of it. The first time they observed it, the tumors grew, shrank, then grew again and ultimately killed the little devil. But before that, the devil managed to produce some offspring. In other words, it passed on its genes. DFTD won again, but this was just the first round. In the next generation, one more succumbed but four Tasmanian devils survived. By now, researchers knew they were on to something. When they tested the surviving devils, they found some antibodies that were not present either in animals that did not have DFTD or had normally progressing DFTD. It’s unclear by now if the resistance is passing on genetically or if there is some other mechanism here, but at the moment, a whopping 10% of that specific population now seems to be immune to the cancer. Hamede described this as an “extremely fast evolution” in response to an “overwhelming threat”.

Immunologist Prof Greg Woods, who has been developing a vaccine to fight DFTD also said the results are promising but more studies are required to understand the mechanism producing the antibodies.

“What we don’t know is whether the immune response contributed to the tumour regression or whether the tumour regressed and that triggered an immune response – in other words, the tumour started dying and that produced antibodies,” Woods said.

 

Two batches of drug-resistant devils have already been released to the wild and so far, none of them exhibited any symptoms of tumors – although sadly, some of them were run over by cars. It’s not the first time such a response was observed. Just earlier this year, researchers from Washington State University observed similar trends in a different population so there may be some hope for the species after all.

This could be important not for the Tasmanian critters, but for us humans as well. Just recently, a study found that Tasmanian devil milk could hold the key to fighting drug-resistant superbugs.

Journal Reference: Demonstration of immune responses against devil facial tumour disease in wild Tasmanian devils.

Tasmanian devil

Tasmanian devil milk might be the secret weapon against superbugs we’ve been waiting for

Tasmanian devil

Credit: Pixabay

Leading medical societies have warned time and time again that antibiotic resistance is looming and the effects could prove catastrophic. While some are working on synthesizing new classes of antibiotics in the lab, other groups are focusing on finding them in nature. After more than three years of research, Australian researchers think they found one of the most promising compounds against superbugs in the milk of an adorable, yet highly aggressive marsupial: the Tasmanian devil.

Momma’s milk

The discovery was made by a team at Sydney University who sequenced the devil’s genome. Devil mothers only need 21 days to gestate a pup, after which development continues in the pouch, as is the case with most marsupials. Given the short gestation and knowing a pouch is far from being the most sterile environment, the researchers presumed that the devil momma’s milk has to offer strong antimicrobial resistance.

Eventually, they found devil milk contains six varieties of peptides belonging to a class called cathelicidins, which act as natural antibiotics. Humans only have one, but most marsupials seem to have them in great abundance. Opossums have twelve and the tammar wallaby carries eight.

The peptides were replicated artificially then tested against a variety of germs, some of whom the most dangerous known to humans. The peptides proved effective against everything the researchers put out. Among the germs was Staphylococcus aureus, a bacteria that’s found in the nose and skin of 30 percent of people. While it’s harmless most of the time, the bacteria can prove fatal if it reaches the blood stream.

Another bacteria was enterococcus, which some strains are already resistant to vancomycin, one of the strongest antibiotics in our arsenal.

Emma Peel with a young Tasmanian devil.  Photo: Emma Peel

Emma Peel with a young Tasmanian devil. Photo: Emma Peel

Last year, an 18-month review into antimicrobial resistance found superbugs might kill 10 million people a year by 2050 or more than cancer.

“There are potential pathogens present in the devil microbiome, so the fact that the under-developed young in the pouch don’t get sick was a clue something interesting was going on,” said Emma Peel, one of the authors of the study published in Scientific Reports. “That’s what inspired our most recent study.”

It’s remarkable that a creature that’s on the brink of extinction might one day save millions of human lives. In only ten years, 80 percent of Tasmanian devil populations have collapsed at the hand of a nasty transmissible face cancer with an almost 100 percent fatality rate. Luckily, some individuals have developed resistance and it seems like the devils will survive. 

Next, the researchers plan on studying koalas as preliminary results suggest their milk also contains similar peptides.

Credit: Wikipedia Commons

Tasmanian devils evolve resistance to transmissible cancer that’s nearly 100% fatal

Credit: Wikipedia Commons

Credit: Wikipedia Commons

In 1996, the first case of devil facial tumor disease (DFTD) was reported by scientists. It’s only one of three transmissible cancers known to man, but also one of the most unforgiving killing almost all of its victims. Ten years later, the iconic Australian marsupial population is down 80 percent and many researchers feared the devil was done for. Genome sequencing, however, suggests the animal has adapted and some individuals have evolved resistance to the cancer.

“Our study suggests hope for the survival of the Tasmanian devil in the face of this devastating disease,” said Andrew Storfer, a Washington State University professor of biology. “Ultimately, it may also help direct future research addressing important questions about the evolution of cancer transmissibility and what causes remission and reoccurrence in cancer and other diseases.”

Storfer has been studying DFTD since it first surfaced and shocked the scientific community. Like everyone else, he was worried by models that suggested given the current rate of decline the Tasmanian devil would be wiped out soon. Yet there might still be hope seeing how some devils survived. Was there any genetic component that helped them survive?

Teaming with other specialists from the United States, Great Britain and Australia, Storfer and colleagues mined DNA collected from devils in three sites in Tasmania before and after the DFTD outbreak. The researchers found two small genomic regions in the DNA samples from all three sites that showed selection-induced changed imposed by the disease.

Five of seven genes in the two regions were related to cancer or immune function in other mammals, the scientists reported in Nature Communications. This suggests, although it doesn’t prove, that the devils are indeed evolving resistance to DFTD. And it’s happening fast too.

“If a disease comes in and knocks out 90 percent of the individuals, you might predict the 10 percent who survive are somehow genetically different,” said study co-author Paul Hohenlohe, assistant professor of biology at the University of Idaho. “What we were looking for were the parts of the genome that show that difference.”

Next, the researchers plan on determining the specific functionality of the identified genomic regions. The hope is that they can then spot those devils that are genetically resistant to DFTD, then breed them to save their species.

40 baby Tasmanian devils born – sparking new hope for the species

In the Tasmanian Devil Ark, is the largest conservation breeding program for the Tasmanian devil, and a much needed one, considering how their numbers are continuing to plummet dramatically.

A desperate fight

Cute little devils, aren’t they?

Tasmanian devils are having the fight of their lives against Devil Facial Tumour Disease (DFTD), a transmissible cancer – the worst kind of diseases, and so far, they aren’t doing so well. Since DFTD was discovered in 1996, population has dropped by over 85 percent.

“Any hopes of resistant animals in the wild are fading,” says Adrian Good, a supervisor at Devil Ark. “It’s inevitable that the disease will wipe out the wild Tasmanian devil population, so we’re breeding a genetically viable insurance population that we can eventually release back into Tasmania.”

While a little pessimistic, this is quite a good explanation of what tasmanian devils are going through; they still have a fighting chance, but against a disease so fantastically cruel, it is a slim one at most. The infectious tumor kills practically any tasmanian devil it infects, natural immunity is only about 10 percent, and every effort to stop or even slow down the disease has failed miserably. Still, there is hope, thanks to an unexpected development: when the disease hit a new, Western population, less devils died, and the ones that did die lived a lot longer; also, some of them started developing antibodies – something that hadn’t previously happened. But still, scientists are reserved and prospects are pretty bleak.

The devil ark

This is why the devil ark has been founded: to breed large numbers of devils in a protected environment, similar to their natural habitat, and release them in the wild after the disease has finished its destructive course. It’s practically an insurance for the species – and so far, things are going pretty good.

“The way we determine our success is by the number of females that breed [rather than by the number of joeys each produces] because we want as much representation from our females as possible,” he says.

Hang on, little devil – good people are giving you a hand

There are 23 females of reproductive age in the breeding program, and 14 of these successfully produced joeys (baby devils) this year – a rate above the 1/2 breeding average. 40 joyes have been born this year, a really great number. It is also best if as many females as possible give birth, because the population will thus be more genetically diverse, better fitted and adapted. This is of course important because…

“The other important thing we do is try to replicate a wild-type scenario so the Tasmanian devils don’t lose their wild traits,” he says.

So the little devils have a fighting chance; let’s just hope that if they can’t win it on their own, humanity will step in and give them another chance, instead of taking the one they had, like we usually do.

Sympathy for the tasmanian devil

The little carnivorous animal has suffered one of the steepest population declines ever to be documented. In just 15 years, it went from being a common animal to the brink of extinction; and the cause is an unusual one: an infectious tumor.

“Devil facial tumor disease has been a devastating, ongoing problem,” said Menna Jones professor of zoology at the University of Tasmania in Australia. “We’ve had no good news since the first we learned of the existence of this disease.”

No good news – until now. The little guys still have hope after all; after the disease started spreading, it reached the northwest corner of the island state of Tasmania where it encountered a new population of tasmanian devils. Something unexpected happened then: the disease changed, and started stalling. Fewer devils are developing the tumour, and the ones that do live longer.

The disease itself is absolutely deadly: it kills virtually any tasmanian devil it infects, the natural immunity is only 1 in 10, and every effort to stop or even slow down the disease have failed miserably. Until now, the best plan zoologists had was to keep some tasmanian devils isolated in shelters until the disease effectively burns out. Should the species actually become extinct – it would be dreadful. Not only because of this itself, and the fact that the tasmanian devil is a national symbol, but also because it is a top predator in its ecosystem. They keep invasive feral cats and foxes in check. Cats and foxes are largely responsible for the extinction of over 20 species of mammals in mainland Australia. In Tasmania, some of those affected species still exist in the wild, like the Eastern Quoll, the Pademelon, and the Bettong. But without the devils around, the last of these species would likely fall to cats and foxes. It would be a dramatic event with huge repercurssions. Long story short, for more reasons than one, the tasmanian devil has to live! Man, I just love saying that!

“The population (in western Tasmania) is declining, but slowly, slower than it did in the east. And the devils are living with the tumor much longer — it used to be that devils in the east with tumors would die within 3-6 months. In the west some are living with the tumors for 18 months,” said Jones.

When researchers analyzied the devils from the West, they found something pleasantly unexpected: two uninfected devils had produced antibodies to the tumor — something no devil had ever done before. Furthermore, the tumour had changed too. The tumors infecting devils in the western area are tetraploid — meaning they have duplicated chromosomes and four sets of each gene instead of two. These tetraploid tumors grow more slowly than the original tumors.

This is absolutely extraordinary news for them! It is the ray of hope they have been expecting for years now, because if either the devils are different or the disease itself has changed, this is what is called a ‘management lever’ – a way to stop the infection from spreading and destroying the entire population. However, Jones remains cautiously optimistic, seeing the current findings as a glimmer of hope that the devils aren’t doomed to extinction in the wild.

Keep fighting, guys! We'll do our best.

“We shouldn’t be too over-the-top hopeful, we shouldn’t breath too huge a sigh of relief,” said Murchison. “The disease is evolving, and tumors tend to evolve much more quickly than their hosts.”

It is my personal hope and belief that researchers will somehow finally be able to deal with disease; it would be incredibly sad, and, as I said earlier, an ecological tragedy for such an amazing population to be doomed because a disease. Keep fighting, guys! We’ll do our best.

Via Physorg