Possums bounce back from Devils on Maria Island

SEPTEMBER 23, 2019

by University of Tasmania

The recent introduction of healthy Tasmanian Devils to Maria Island was initially bad news for the local possum population, a species blissfully ignorant of the predator's existence.

But the ability of the prey species to rapidly modify its foraging behavior is the subject of a new report from the University of Tasmania published in the journal Ecography.

"In response to extinction fears, devils were introduced to Maria Island, where their abundance rapidly increased," according report lead-author and UTAS School of Natural Sciences researcher Calum Cunningham.

"This was really important for safeguarding the devil's future, but it also provided a unique opportunity to research how apex predators structure ecosystems."

And the Maria Island experience could have implications for the "rewilding" of apex predators across the world, according to Mr Cunningham.

"Rewilding is a management approach that aims to restore important ecological processes by introducing species that play important roles."

Mr Cunningham said that declines of large carnivores across the world had reduced the "landscape of fear" that constrains the behavior of other species.

"Our study shows that recoveries of top predators can re-establish missing controls on the behavior of other species," he said.

The Maria Island study used a foraging experiment specifically designed to measure how possums—a key prey species of devils—perceive predation risk. The experiment compared possum behavior before devils were introduced to the island, and again after devils had become very abundant.

Read on

Human drugs could help treat transmissible cancers in Tasmanian devils

April 9, 2018, University of Cambridge

Transmissible cancers are incredibly rare in nature, yet have arisen in Tasmanian devils on at least two separate occasions. New research from the University of Cambridge identifies key anti-cancer drugs which could be trialled as a treatment for these diseases, which are threatening Tasmanian devils with extinction.

The research also found that the two Tasmanian devil transmissible cancers are very similar to each other, and likely both arose due to susceptibilities inherent to the devils themselves.

Tasmanian devils are marsupial carnivores endemic to the Australian island of Tasmania. The species is considered endangered due to devil facial tumour 1 (DFT1), a cancer that is passed between animals through the transfer of living cancer cells when the animals bite each other. DFT1 causes grotesque and disfiguring facial tumours, which usually kill affected individuals.

The DFT1 cancer first arose in a single individual devil several decades ago, but rather than dying together with this devil, the cancer survived by 'metastasising' into different devils. Therefore, the DNA of the devils' tumour cells is not their own DNA, but rather belongs to the individual devil that first gave rise to DFT1 all those years ago. Remarkably, DFT1 cells can escape the devils' immune systems despite being in essence a foreign body.

The DFT1 cancer was first observed in north-east Tasmania in 1996, but has subsequently spread widely throughout the island, causing significant declines in devil populations.

Read more at: 

Tasmanian devil milk fights superbugs

18 October 2016

Milk from Tasmanian devils could offer up a useful weapon against antibiotic-resistant superbugs, according to Australian researchers. 

The marsupial's milk contains important peptides that appear to be able to kill hard-to-treat infections, including MRSA, say the Sydney University team. 

Experts believe devils evolved this cocktail to help their young grow stronger.

The scientists are looking to make new treatments that mimic the peptides.

They have scanned the devil's genetic code to find and recreate the infection-fighting compounds, called cathelicidins.

PhD student Emma Peel, who worked on the research which is published in the Nature journal Scientific Reports, said they had found six important peptides. 

These appear to be similar to peptides in the milk of other marsupials, which means these animals are worth studying too. 

"Tammar wallabies have eight of these peptides and opossums have 12," she said, adding that studies into koala's milk had now started.

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Tasmanian devils’ decline ‘driven by climate change’, new research shows

Widespread hunting and facial tumour disease not primary reason for low genetic diversity and historic population slumps

Oliver Milman

theguardian.com, Wednesday 5 November 2014 01.52 GMT

Tasmanian devils’ low genetic diversity and previous population declines were driven by climate change rather than hunting or a rampant facial tumour disease, new research has found.

A study of the largest ever genetic dataset of Tasmanian devils found that widespread bounty hunting of the animals after European settlement of Australia is not the primary reason for the species’ worryingly small gene pool. Nor is the devil tumour disease that was discovered in 1996 and has been blamed for a 90% decline in devil numbers in some places.

Researchers found that Tasmanian devils have, in fact, lived with low genetic diversity for thousands of years, having suffered two huge population drops, wiping out around 80% of animals in the past 50,000 years.

The first population slump occurred during the last ice age, around 20,000 years ago, with the next decline occurring 3,000 to 5,000 ago when the climate became much drier. Tasmanian devils were once spread across Australia but are now confined to Tasmania.

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Join “The Great Poo Hunt” to keep tabs on invasive species, get free food, pick up turds

They do things a little differently in Tasmania. Case in point: a recurring shit-finding expedition called “The Great Poo Hunt.” Gathering butt chocolate from Tasmanian devils and the like sounds so fun, 20 people have already signed up!

But they need 20 more, so hop to it! After all, doo-doo can tell a lot: where someone is, what someone’s been eating (chili-cheese Fritos AGAIN?!). I do it all the time to find out whether my lovers have found my secret snack supply in the bottom of — oh NO you don’t!

Anyway, volunteers get free food and lodging during the five-day hunt, PLUS the knowledge that they’re doo-ing something pretty important:

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Tasmanian devils have new US home

A group of Tasmanian devils have taken up residence in San Diego Zoo in California as part of a conservation programme to protect the endangered species.

Video

Tasmanian Devils to be Released into Australian "Halfway House"

Tasmanian devils and an assortment of other endangered species will be released into a "halfway house" in Australia. But it's not because they've got into trouble with drugs or just got out of prison … so far as we know, anyway. The animals are being released into a contained reserve in Australia as a preliminary step to see how they do in the new environment, with the ultimate goal of releasing them into the wild, according to the Guardian.

Four devils will be released, as well as 40 Leadbeater's possums and 40 helmeted honeyeaters. All the animals are endangered. Helmeted honeyeaters, a type of bird, are in particularly bad shape, with only about 60 remaining in the wild.

Tasmanian devils are endangered primarily due to a type of infectious cancer, and their numbers have plummeted in the last 15 years, according to the International Union for Conservation of Nature. If cancer-free individuals can be successfully reintroduced to Australia, where they once lived before going extinct about 400 years ago, it could improve the species' chances of survival.

http://www.livescience.com/39139-tasmanian-devils-halfway-house.html

How Contagious Tasmanian Devil Cancer Goes Invisible

Stephanie Pappas, LiveScience Senior Writer

A cancer that has wiped out 70 percent of wild Tasmanian devils became contagious by "switching off" certain genes that would otherwise enable the immune system to recognize it, a new study finds.

Devil facial tumor disease is one of only two contagious cancers in the world (the other affects dogs and is nonfatal). It spreads when the Australian marsupials bite or nip each other, transmitting cancerous cells that grow into enormous face tumors. The cancer either metastasizes to other organs or prevents Tasmanian devils from eating or drinking. Either way, death usually occurs within six months. Experts predict the species could vanish within 20 years if the tumor disease isn't stopped.

The immune system should catch these tumor cells, but the cancerous invasion causes no immune response in devils, said Hannah Siddle, a University of Cambridge immunology researcher. Siddle and her colleagues have now discovered why: The tumor cells lack surface molecules called major histocompatibility complex molecules. These MHC molecules allow the immune system to detect the invading cells. Without them, the cancer is essentially invisible.

Cotinued:  http://www.livescience.com/27804-contagious-devil-tumor-disease.html