Peanut butter, cameras and spotlights are all part of Sandra Gilfillan's bag of tricks for studying WA's wallabies.
It’s just after dark and West Australia-based fauna ecologist Sandra Gilfillan and a team of volunteers are driving through a mix of scrub, mallee heath and woodland at a slow 20 km per hour.
Sandra Gilfillan has spent the past 12 years working as an ecologist in the south coast of Western Australia. Photo: Grant Westthorp.
Braving the cold night air, they are shining a spotlight out of the window and anticipation is mounting as to what they might see.
'That’s what makes spotlighting so exciting – especially for first-time volunteers – you never know what you’re going to find,' says Sandra. And they get to see all sorts of creatures, ranging from owls and other nocturnal birds to brush-tailed possums.
'First, you see a pair of eyes shining out at you. You can tell which animal they belong to by the colour of the eye shine. Foxes, for example, have a bright white shine, but we’re looking for the red eye shine of the wallaby.'
Wallabies in the Fitz-Stirling region
Sandra and the team are in Western Australia between the Fitzgerald River and the Stirling Range National Parks, part of the Gondwana Link project, and their aim is to establish the whereabouts and numbers of the tammar and black-gloved wallabies.
The good news for Bush Heritage supporters is that survey results indicate that there are 12 tammar wallaby populations, which is more than previously thought.
Solving the monitoring puzzle
Finding the best way to monitor the wallabies took quite a bit of initial detective work.
'Spotlighting is a good way to see black-gloved wallabies. They tend to sit down and look at you or carry on feeding,' says Sandra, describing them as Australia’s prettiest wallaby with their gun metal grey coats, white cheek stripes, black gloves and black ear tips. 'But the tammars stay closer to the bush and are harder to see.'
Remote camera monitoring works well for both species but when the project started in 2007 there were just four cameras – not nearly enough to cover all the dense-canopied moort woodlands favoured by the tammars.
So after the first season, there were plenty of shots of photogenic black-gloved wallabies, or spotlight sightings at various sites including Bush Heritage’s Peniup Creek and Chereninup Creek reserves, but none of the tammars.
Undeterred, Sandra came up with other more cunning ways of tracking the tammar wallabies. She looked in their favourite habitats for droppings and also compared the footprints of the two species, but both methods left her none the wiser.
Her next plan was to collect hair samples. One method involved setting up specially designed sticky-sided plastic tubes and arches. Lured in by tasty peanut butter and apple baits, the wallabies poke their heads in and leave hair behind on the sticky-sided tape.
'You can tell the two wallabies apart by looking at the hairs under a microscope,' explains Sandra.
And the winner is...
The project has had most success with remote camera monitoring, thanks to the Perpetual Foundation, whose generous funding allowed us to purchase more cameras and survey a wider area.
'Now we know more about where the wallabies live and what their numbers are,' explains Sandra, 'we can monitor in the long term whether activities such as fox control and habitat creation through restoration are helping to boost their populations.'
Discovering tammar populations at new sites has been a highlight for Sandra.
'It’s a real thrill discovering a previously unknown population. And the tammars are quite elusive so when you see one it’s very special.'
Thanks to Perpetual Foundation for its support of ecological monitoring in WA this year.
By Charlotte Francis