Vaccinated devils find wild love
Vaccinated Tasmanian devils released into wilderness areas are breeding with wild devils, raising hopes of a population resurgence in targeted areas.
Biologist David Pemberton said the first of a number of births had been recorded during monitoring at Stony Head in the north in June.
“This is a major milestone for the Wild Devil Recovery Project,” Dr Pemberton said.
“As part of our monitoring, biologists trapped a four-year devil with three pouch young.
"The tracking data is suggesting that the introductions provide an influx of genetic diversity into an area up to 20km from the release site."
As the scientist who led the development of a vaccine against the devastating Devil Facial Tumour Disease (DFTD) announced his retirement, the vaccine was found to be less than 100 per cent effective.
Professor Greg Woods of the Menzies Institute for Health Research said that three of 33 released devils at Stony Head had developed small facial tumours.
“Clearly the vaccination isn’t 100 per cent effective,” he said “We will analyse the samples, try to modify the vaccination and try again.
“Our next challenge is to determine why three devils were not protected and to modify the immunisation procedure to provide full protection.
“The devils are breeding in the wild, so the numbers are going up. This minor hurdle is something we can overcome with more research.”
Meanwhile, the majority of vaccinated devils released into the wild are coping well and putting on weight, as well as producing young.
Dr Sam Fox, of the Save the Devils Program, said none of the devils freed at Mount William National Park in May had been killed by vehicles.
“This is encouraging news as data from previous releases found captive devils to be particularly vulnerable in the first two to four weeks as they disperse away from the release site and transition back to wild living,” she said.
On the Forestier Peninsula, in south-eastern Tasmania, recent monitoring has also found two of three females released in 2015 carrying a second generation of joeys, while five females born in the wild also had juveniles.
Dr Pemberton said there were at least 43 joeys in the pouches of 12 mothers at Stony Head, including two of the females from last year’s release.
“A population like that [at Stony Head] usually hovers around 20,” Dr Pemberton said.
“With  babies in the pouches, if they can wean them that’s basically going to double the population."
He said there had been positive breeding results from Maria Island, as well as Forestier Peninsula and Stony Head.
“All these sites have bred and [some] are second and third generation.
“The goal of the ... project is to get genetic diversity into the population and the numbers up to give evolution a chance.”
When Professor Woods, then an expert in human immunology, started researching the disease in 2005, the wild population was in rapid decline.
Sightings in the north-east, where the disease was first detected, were estimated to have declined by 95 per cent.
Little was known about the species — especially its all-important immune system.
With extinction a real possibility, the Save the Tasmanian Devil Program began to establish an “insurance population” of healthy devils that had not been affected by disease.
“We basically knew nothing about the devil’s immune system," Professor Woods told The Mercury.
"In fact, it was amazing how little we knew about the marsupials."
Menzies' devil team began with the professor and one PhD student and has grown to about a dozen members who work with scientists researching devil genetics across Australia and the world.
The team’s painstaking laboratory work revealed in 2015 that the devil’s own immune system was capable of mounting a response to DFTD.
More recent work has demonstrated that immunotherapy can cure devils of the transmissible cancer.
A research paper published in Scientific Reports in July confirmed that the tumours and the devils' immune responses were both evolving quite rapidly.
Lead author, Rodrigo Hamede of UTAS, said: “Several studies have recently suggested that devils are adapting to DFTD. However, two different genetic lineages of tumours have different growth rates and, therefore, [different] impact on devils."
Dr Hamede said some devils' immune systems might be capable of altering the growth rate of tumours.
Professor Woods, 62, said the path to an all-important one-shot vaccine still had many “twists and turns”.
He said he planned to stay on for the journey as a part-time researcher and mentor of postgraduate students.
Image courtesy of UTAS
Footnote: Devil Ark's Tasmanian devil breeding program at Barrington Tops, NSW, added 51 new joeys to its population in the recent breeding season. Since starting with 44 devils in 2011, Devil Ark has seen around 250 joeys born over five years. The total captive devil population in 26 institutions is now well past the initial target of 500.
1 August 2017, Edition 186