Conservatives in Tasmania could undermine the decision to take the risk Tasmanian Devils on a small island after a new study found that alien invaders have wiped out the entire little colony penguins living there.
Tasmanian Devils (Sarcophilus harrisii), the largest in the world carnivorous were introduced to Maria Island, a 45-square-mile (116-square-kilometer) island east of Tasmania by the Tasmanian Department of Primary Industries, Parks, Water and Environment (DPIPWE) in 2012. The government agency hoped to create a new demon population for prevent the extinction of species from a deadly disease that has diminished their numbers in Tasmania.
However, the introduction of one species meant the end of another species: A new DPIPWE survey showed that the introduction of devils to the island wiped out 3,000 pairs of small penguins (Eudyptula minor) living on the island, according to Guardian.
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Critics now blame the DPIPWE decision to bring the demons to Maria Island and the department’s subsequent handling of the situation.
“This was a predictable and avoidable outcome,” Eric Science Woehler, an ornithologist at the University of Tasmania and head of the BirdLife Tasmania conservation group, told.
Insurance policy
The International Union for Conservation of Nature, which maintains a list of endangered species, classifies the Tasmanian devil as endangered. A major threat to the species is the emergence of a rapidly transmitted form of cancer known as the devilish face tumor disease, which has killed 90% of their population (which is mainly confined to Tasmania) since the disease appeared for for the first time in 1990, Direct science previously reported. DPIPWE scientists believed that the only way to prevent an extinction of the devil was to create isolated populations of healthy individuals away from Tasmania.
In addition to keeping devils safe on Maria Island, conservatives thought the transplanted individuals would help control the island population of small predators, such as feral cats and pests; traditionally, officials had tricked predators to protect bird populations, according to The Guardian.
Similar attempts to bring Tasmanian demons into Australian territory have been successful and wild demons have recently been born there for the first time in over 3,000 years, Live Science previously reported. However, the young population on Maria Island grew rapidly out of control from 28 individuals, introduced between 2012 and 2013, to more than a hundred by 2016, according to The Guardian.
“The devil population is currently able to reach a population size range between 60-90 individuals,” a spokesman for DPIPWE Live Science, which they claim is the current capacity carried to “reduce the impact on the ecology of the island “.
The nightmare of preservation
With that population boom, Tasmanian demons became the dominant predator on Maria Island, and some endemic species, such as the little penguin, could not adapt as quickly as they survived the attack.
“The devils ate the adults and the young,” Woehler said. “Penguins that were not preceded left the colony in the face of looting pressure,” they are likely to join other colonies in Tasmania, Australia or even New Zealand.
The devils also killed and ate short-tailed shear waters (Puffinus tenuirostris), significantly reducing the number of birds on Maria Island, according to a study published in 2020 in the journal Biological Conservation.
Other bird species at risk of devil appetite include the Cape Barren goose (Cereopsis novaehollandiae) and native Tasmanian chickens (Tribonyx mortierii), Tha Woehler. “All species of birds that nest on the ground and feed on the soil are at potential risk,” he added.
Avoidable result
One of the biggest criticisms of Woehler and others about the project is that so far, DPIPWE had not properly monitored the penguin population, so the organization had “no idea” what was going on as a result, Woehler said. “Parks staff did not undertake any monitoring for 12 years, and that was when they discovered no remaining penguins,” Woehler said.
The lack of monitoring also means it is unclear whether the Tasmanian demons had any impact on predatory populations as expected, Woehler said.
However, DPIPWE claims that the monitoring was carried out on Maria Island, although it does not seem to have done them any good.
“The Save the Tasmanian Devil (STDP) program constantly monitors, evaluates and reviews the devil population and program activities,” a DPIPWE spokesman for Live Science said. “All effective conservation programs are adaptive and STDP will continue to evolve in line with new knowledge in science and new priorities.”
Proper monitoring may have been able to save the penguins, but the project should never have gotten a green light in the first place, Woehler said.
In 2011, before Tasmanian devils entered Maria Island, DPIPWE released a report predicting the introduction of carnivorous marsupials would have “a negative impact on small penguin colonies and shear waters on Maria Island through devil predators. “, according to The Guardian.
However, the desire to save Tasmanian iconic demons from the disease of the devilish face tumor led to the hasty decision to present them independently, Woehler said.
“The result was predicted by a lot of people,” Woehler said. More research should have been done before the demons entered to help inform the DPIPWE decision, he added.
Ironically, new studies suggest that the indigenous devil population in Tasmania is now more likely to survive the outbreak of facial tumor in the devil, as the disease has begun to spread much more slowly, according to a study published in 2020 in the journal science. Therefore, bringing Tasmanian devils to Maria Island was ultimately unnecessary.
Not too late
Although the introduction of Tasmanian devils to Maria Island has caused a great deal of ecological damage, there is still hope that the problem will be fixed.
By removing the demons from the island, there is a chance the little penguins will return home, Woehler said.
“They are responding to predator pressure,” Woehler said. “Take away the pressure and the birds will be back.”
However, there is no indication that a devil removal project is underway soon, Woehler said.
Originally published in Live Science.
