Endangered Mammals

By Mary Bremner

As we travel between Point Roadknight and Urquhart Bluff, our eyes are drawn across the white caps to the lighthouse. But who knew that the narrow stretch of vegetation that covers the sand dunes under our gaze is home to some of our region’s rarest and most endangered mammals?

Not I, at least not until I spoke with Aireys Inlet resident, Dr Barbara Wilson, about her four decades of investigation into some of our extraordinary native fauna.

Barb is an Adjunct Associate Professor at Deakin University and runs her own ecological consultancy, working on national, state and local government projects.

Barb’s passion for our local wildlife was ignited when she started a longterm study based in the Eastern Otways, as part of a PhD at Deakin University.

She completed seven years researching the impact of the 1983 ‘Ash Wednesday’ bushfires on mammals and plants, finding out how long it took them to recover.

There are two very special small mammals that make Barb’s eyes light up. They are nocturnal, very shy and you must be very fortunate to see them. We’re talking about the swamp antechinus and the New Holland mouse, both listed as threatened species.

The New Holland mouse could easily be mistaken for the common house mouse, to which it is actually no relation. It is fluffier, has large eyes and a longer tail. Best of all it doesn’t smell mousy. The slightly larger swamp antechinus is a carnivorous marsupial –it has a pointy snout, short ears and a long tail.

Barb’s studies showed that both species, which existed in good numbers prior to the 1983 fires, had been decimated. Two years later, the researchers happened by chance upon a small population of the New Holland mouse, which had survived in a tiny

The native bush rat (Rattus fuscipes). Photo by Fern Millen

unburnt patch. However it took about 12 years for the swamp antechinus to reappear, albeit in small numbers.

It was a project Barb took on for the Western Australia government, driven by the state’s need to conserve its threatened water supplies, that led to her understanding of the impact of climate change on biodiversity.

On returning to Victoria, Barb was interested to see how the local mammals were faring and quickly realised they were in trouble. Surveys conducted between 2013 and 2018 revealed 67 per cent of sites exhibited large to severe decreases in numbers, with only eight individual swamp antechinus at sites where previously they’d been in abundance. Further there has been no record of the New Holland mouse since 2003. The research found strong evidence that, for both species, reproduction is related to rainfall, and the millennial drought had a huge impact on their decline. found Barb looking specifically at the impact of climate change on the flora and fauna of the Eastern Otways, where many species are reducing in numbers. Barb’s work involves studying the effect of the loss of vegetation through impacts such as the devastating plant pathogen Phytophthora cinnamomi and variations in rainfall and temperature on the populations.

It was during this project that Barb and her team discovered, to their surprise and delight, thriving populations of a variety of mammals in our local sand dunes, adjacent to the Great Ocean Road. Barb describes it as ‘one of the richest remnants and refuges for mammals in the Eastern Otways that we’ve found – very small and very important’. Animals found there include the swamp antechinus, brown bandicoot, longfooted bandicoot and white dunnart. Barb had known that some animals had recovered there after the 1983 fires but only recently discovered that they’d survived in such numbers.

‘It was such a relief,’ Barb said. The animals have also been found in the gullies leading up from the sand dunes, such as Hutt Gully, and these are important refuges that allow their migration inland. Barb is working with Parks Victoria and now the Department of Environment, Land, Water and Planning (DELWP) to have these areas protected.

Barb often works on projects with her ecologist husband, Dr Mark Garkaklis. A typical day in the field will involve Barb and her co-workers setting up mammal traps. A favourite food for our furry friends consists of peanut butter, rolled oats and honey fashioned into little balls and used for bait. Cameras are also used to capture vision of the animals, and baits are sometimes laid to lure them into view.

Helpless to do anything about changes in weather patterns, much of Barb’s work focusses on managing the other impacts. Preservation of the known animal habitats is crucial but Barb’s projects are taking it one step further with the construction of man-made refuges.

Research students have built tunnels and placed them in burnt areas to see whether mammals will use them. So far they have been successful, with white-footed dunnarts, dusky antechinus and echidnas all sighted in residence, suggesting these refuges may become part of a long-term strategy. While Barb is sad that such measures are necessary, she can also see the potential for use in areas where vegetation has been removed in ways other than fire – such as the damage caused by Phytophthora.

Barb continues to work closely with PhD students at Deakin University and has also been part of the Corangamite Catchment Management Authority’s Wild Otways Initiative – a project aiming to conserve threatened mammals. This involves analysing the data already gathered and going out to do more surveys to see if they can locate bandicoots, potoroos and native rodents such as the broad-toothed rat, smoky mouse and New Holland mouse – all very rare across the Otways.

The recent discovery of three swamp antechinus in the dunes at the head of the Painkalac Valley, along with a dead specimen on a privately-owned conservation area further up the valley, has caused a stir among local naturalists. Once in good numbers, this species hadn’t been recorded in the valley in the past decade.

Investigations show they have their cousins, the agile antechinus, along with bush, swamp and water rats for company. Barb is planning to do some trapping and more camera work and won’t be surprised to find continuous populations up the valley, giving further strength to arguments for revegetation of this rich natural environment.

Asked what excites her most about her work, Barb said she loves the moment when she can hold a species she hasn’t seen for a long time in her hand. She had this thrill on rediscovering our small populations of swamp antechinus. However Barb hasn’t held the elusive New Holland mouse in her hand since 2003. She hasn’t given up hope though – the Wild Otways project includes consideration of whether they could be reintroduced to the Eastern Otways from populations in Gippsland. It is the influence that she can have to improve and make sustainable our wildlife communities that continues to motivate Barb in her work.

Asked what we can do to help aid the survival of our precious native fauna, Barb suggested being mindful of our environment as not just a place for us to enjoy, but also as a habitat for animals. As most of them are nocturnal, we won’t be aware of their presence. Report any observations to Parks Victoria or DELWP. Avoid contributing to the spread of Phytphthora by cleaning your boots and staying on the tracks. Plant indigenous species in your gardens and bush blocks and, where applicable, design your fences to allow for the passage of native animals – in accordance with Surf Coast Shire Council guidelines.

With our environment in such a precarious position, Dr Barbara Wilson’s main focus now is to train people for the future.

It’s one of the joys of her work, to be out in the bush working side by side with enthusiastic research students from the universities and young people from Parks Victoria and DELWP. They are keen to soak up all that Barb has to share with them.

With so much good work going on, it might not be long before Barb can hold a New Holland mouse in her hand.

Female swamp antechinus. Photo Credit Kristen Agosta

Dr Barb Wilson with husband Dr Mark Garkaklis in the field. Photo by Fern Millen