SCIENTISTS FIND RARE “SUICIDAL REPRODUCER” MARSUPIAL SURVIVING IN BURNT QUEENSLAND FOREST

There’s good news for one of Australia’s rarest mammals, the silver-headed antechinus, amid fears it had been pushed to the brink by the 2019-20 megafires.

The shrew-like marsupial, whose males die en masse from stress after frenetic mating sessions, has been found surviving in burnt forest south of Gladstone, in a search funded by the World Wide Fund for Nature-Australia.

Scientists managed to trap 21 silver-headed antechinuses (Antechinus argentus) in Bulburin National Park during field work from late May to early June of 2021.

Despite those positive results, concerns remain for the species survival.

The silver-headed antechinus was only formally identified as a separate species in 2013 and so far is known to occur in just three locations: Blackdown Tableland National Park, Kroombit Tops National Park and Bulburin National Park.

Bulburin National Park is the species’ stronghold but more than 3,000 hectares of the park’s rainforest and wet eucalypt forest were burned in 2019, representing about a third of its Bulburin habitat.

The federal government named the species on a priority list of 20 mammals requiring urgent management intervention following the 2019-20 megafires.

Antechinus expert Dr Andrew Baker and PhD candidate Stephane Batista, both from the Queensland University of Technology, led the search for the silver-headed antechinus in Bulburin National Park.

“Pleasingly, we found 21 individuals across burnt and unburnt habitat which is great, it means they are persisting,” said Dr Baker.

“However, with a third of their habitat burned, we’re concerned the silver-headed antechinus population at Bulburin has been heavily impacted."

“Weeds are growing in some badly burnt areas which could change the vegetation structure and further impact the population. Feral pigs, which trample habitat, are also a problem."

“The megafires demonstrated that even rainforest areas are now vulnerable. With predictions of drying and more intense fires due to climate change, we’re going to have to work hard to save this species,” Dr Baker said.

WWF-Australia Head of Healthy Land and Seascapes, Darren Grover, who joined the search, said field work to assess wildlife populations after the fires was crucial.

“It’s understandable the koala became the wildlife symbol of the megafires, but there were many other species impacted that also deserve attention,” Mr Grover said.

“The silver-headed antechinus was only described to science in 2013, was immediately declared endangered, and then hammered by fire. We can’t let its story be ‘discovered today, gone tomorrow ’."

“To help all our wildlife, WWF has launched Regenerate Australia – the largest nature regeneration program in the nation’s history,” he said.

Dr Baker says more research is needed into the feisty little marsupial which will “tear the heads off introduced house mice and eat them” but primarily feeds on insects and spiders.

Like all 15 species of antechinus, the silver-headed variety is a suicidal reproducer. No male lives past its first birthday. During a two-week period, the males mate with as many females as possible, in marathon sessions which can last 14 hours. Females live long enough to raise the offspring and may survive to breed in a second, and rarely a third, season.

“With the males, high testosterone levels from super-sized testes causes a failure of the switch that turns off the stress hormone cortisol. So they get flooded with cortisol during the breeding season and ultimately it poisons them. The males suffer internal bleeding, their hair falls out, sometimes they go blind. Even then, they may stumble around looking for females to mate with until they die,” said Dr Baker.

Stephane Batista’s PhD study has revealed new insights into the silver-headed antechinus. Information that will be crucial to the development of a recovery plan for the species.

Trying to find a small animal in dense forest is incredibly difficult so Stephane enlisted the help of specially trained detection dogs from Canines for Wildlife.

First, Stephane does computer modelling to identify potential habitat. The dogs search these areas and if they pick up the scent of an antechinus, Stephane knows where to place baited elliott traps or sensor cameras.

“Since 2019 the results we have been getting here are quite amazing. We’ve found the silver headed antechinus in so many new sites across this national park,” Ms Batista said.

“It was here that we discovered that the species also lives in rainforest which we did not know before."

“The first step in any recovery plan is identifying an animal’s range and by using the detection dogs we are discovering where silver-headed antechinuses are located across the national park and the vegetation they prefer,” Ms Batista said.

About Regenerate Australia

Regenerate Australia is the largest and most innovative wildlife recovery and landscape regeneration program in Australia’s history. Launched by WWF-Australia in October 2020, the multi-year program will rehabilitate, repopulate and restore wildlife and habitats affected by the 2019-2020 bushfires, and help to future-proof Australia against the impacts of changing climate. Find out more at www.wwf.org.au/regenerate-australia