Postcards from the Field: Which Wallaby?

I had a problem: Two uncommon wallaby species live in the Fitz-Stirling area of WA, the tammar and black-gloved wallabies. The Gondwana Link project – a landscape-level conservation project – has an ambitious plan to increase the numbers of both species by 30% over the next 7 years. But how to work out whether their efforts were paying off?

It was my job to work out a way of monitoring the two wallaby species without capturing them, which is very harmful to the animals. In particular, I needed to work out which species lived where, and how any increase in numbers could be measured.

Bush Heritage has a handful of reserves that are part of the Gondwana Link project. On these reserves, fox control and revegetation work should both greatly improve the prospects of the resident animals. But Bush Heritage needs to make certain that their work is producing results on the ground, so they were looking for a way to get some data on wallaby numbers and distribution.

Both the tammar and the black-gloved wallabies are shy, don't move around during the day, and aren't very common in the area. So where to start working out which species occurred where?

The wallabies are most active at night, so spotlighting is an obvious solution, but is limited to places you can drive through. In this case, I tried another method – remote cameras.

Here's me setting up a remote camera in possible wallaby habitat. I'm chopping up some apple, which I use to entice them to get in nice and close. When the wallabies come in to take the food, their movements trigger the camera.

The good news is that the cameras worked well, which was very exciting. Here's a black-gloved wallaby I snapped one night. Looks like she has a joey in there about ready for eviction!

And the results? Well, I got photos of black-gloved wallabies on a number of properties – including Bush Heritage's Monjebup North, Peniup Creek and Chereninup Creek reserves. 

The intriguing thing is that no tammar wallabies were snapped during the entire first season of remote camera monitoring. But from other sightings, I knew that the tammar wallabies were definitely in the area. It seems that the remote cameras weren't picking them up for some reason. So, I needed to look at other possible ways of detecting the tammars.

This mort woodland is one of the preferred habitats for tammars. I initially tried looking in habitat like this for the wallabies' scats (that's another name for droppings!). I wondered whether it might be possible to work out which species they'd come from. Unfortunately, based on their size, shape and appearance, there's no foolproof way of telling the two species' scats apart.

Next, I looked at the footprints of the two species. The black-gloved wallaby is a bit bigger than the tammar, so has bigger feet. Also, tammars tend to have a large toe that is slightly longer in relation to the short toe. The footprint on the left is from a black-gloved wallaby and the one on the right is a tammar. Can you spot the difference?

It actually turned out that the difference wasn't marked enough to confidently tell the difference between the two types of wallabies.

There's another thing that wallabies leave behind when they pass by – hair. Tammar and black-gloved wallaby hairs look different under a microscope. With a bit of practice, you can tell them apart quite easily. So, I set up some hair collection traps – like these vertical sticky poles – thin metal poles (golf clubs!) wrapped with double-sided tape. When the wallabies brush against the poles, they leave hair behind.

Another method I tried was these hair collection arches, with double-sided tape stuck to pieces of plastic. I used peanut butter and apple to tempt the wallabies.

Hair collection seemed to work well with the tammars, but not so well with black-gloved wallabies. I decided that the hair collection technique had potential, but would need more testing before I could use it widely.

I also found that by putting remote cameras in habitat that I now know is more suitable for tammars I successfully obtained some photos, like this one here. I now know there are twelve tammar sites in the area, including on Bush Heritage's Monjebup and Chereninup properties.

So, what I learned from all this testing was that the best way to detect these shy animals is using a combination of techniques – a kind of hybrid approach.

A combination of spotlighting, remote cameras, and hair collection may be the best way of giving us the answers we need.

Whatever methods I use, when I search again for these wallabies, I hope to find them a little easier, and to see them thriving! 

From top: all photos by Sandra Gilfillan, except photo 2 by Eddy Wajon.

Dr Sandra Gilfillan
Wallabies Project Officer, Gondwana Link

Sandra has spent the past 12 years working as an ecologist in the south coast area of WA. Her specialty is mammals.

Read more about Bush Heritage's work as part of the Gondwana Link Project.