17 Dec 2019


Senior Manager Species Conservation, WWF-Australia

Protecting Australia's threatened species is a tricky business. For one thing, our continent is vast, and many of our most endangered animals live mysterious lives in remote locations. Just getting a fix on how many remain can take years of patient detective work. The fact that Australia has the worst mammal extinction rate on the planet, and currently lists more than 450 animal species as threatened, reflects the scale of the challenge.

In the past, we've relied heavily on traditional survey methods like sensor cameras, tagging and analysing scats. This can be very expensive and time-consuming, especially in isolated Country. These techniques also have their limitations in providing a clear and comprehensive picture of species distribution and abundance, because aerial observations by humans aren't always accurate.

So if we are to turn the tide on Australia’s extinction crisis we have to learn how to work smarter. Which is why WWF-Australia recently joined forces with Charles Darwin University (CDU) to trial a new method for monitoring species.

The CDU team took an off-the-shelf drone and attached thermal imaging and zoom cameras to test whether they could detect and positively identify agile wallabies in open grassland and woodland. After first determining what height the drone could be flown at without disturbing the wallabies, the cameras documented a four-hectare area at East Point, near Darwin.

Drones are helping to monitor black-flanked rock-wallabies

Both cameras recorded images at the same location at the same time, with the flight periodically interrupted to zoom-in to capture high-resolution shots of anything of interest (such as a wallaby) to aid positive identification. ‘Back in the lab’, the two sets of images - the thermal images and the regular photographic images – can be overlaid to create a single landscape picture made up of different artificial colours. In the following example, the visual and thermal images are overlaid with a small offset – notice the green thermal image are of lower resolution due to the thermal camera characteristics, but the thermal images of warm-blooded animals tend to be easier to spot due to their temperature being greater than the surrounding terrain and vegetation.

Thermal images can also be extremely useful to identify animals at night or dawn/dusk, which is important for surveying many of our nocturnal animal species.

However, such manual methods are very time consuming and prone to errors. An alternative approach is for computer algorithms to search the images for a target species based on a “template” (such as size, shape, temperature). An example of the thermal and visual images below shows “boxes” surrounding the computer detected location of the target wallaby species. As can be observed with the thermal image (left), manual detection of animals from the background can be difficult in tropical regions due to high ground temperatures. However, in the East Point test, the computer algorithms were 100 per cent successful, with no animals missed, and any false detections. Further, based on the temperature and size data, additional useful biological data can be estimated. such as the metabolic rate, sex (for species with sexual size biomorphism), and herding patterns.

These methods could prove a technological breakthrough in our bid to save a whole host of animals

These methods could prove a technological breakthrough in our bid to save a whole host of animals, including the far less common black-flanked rock-wallaby (wiliji) (Petrogale Iateralis). This shy species lives only in the rocky escarpments of the west Kimberley region of Western Australia. We know very little about it - few people have even seen a wiliji - but we fear there may be as few as 200-300 left on Earth.

WWF-Australia is not unique in exploring ways to employ drones in conservation, but there is something special about our approach. We're testing the capabilities of such technology to see whether it could play a role in our collaboration with people who know these landscapes better than anyone - Indigenous land rangers. Since 2011 we've been working with Nyikina Mangala Rangers in the Kimberley on the conservation of threatened and culturally important species like the wiliji. Indications are that drones might be really useful across far-flung regions, with a minimum investment in time, money and training. So drone-mounted cameras could become a valuable addition to the rangers' toolkit.

It's early days of course. There are still regulatory and technical challenges to overcome - including battery power, which limits coverage area and flight times, and licensing requirements for higher-capability drones. Once we have the data, it then needs to be analysed and interpreted, to help us draw conclusions about things like habitat preference, species distribution and behaviour. However, the trial results are promising and we’ll continue to investigate ways we can adapt emerging technology for practical conservation purposes.

We're committed to this approach because it’s not just the wiliji that stands to benefit. Over 450 Australian native species are similarly at risk of disappearing forever and we must work hard to urgently fill gaps in our knowledge. If fit for purpose, and used judiciously and strategically, technology such as drones have the potential to do just that.

A ranger enjoying a close encounter with a wiliji (black-flanked rock-wallaby) in Erskine Range= west Kimberley
© Jacqueline Batrus / Nyikina Mangala Rangers / WWF-Aus

But let's not get carried away with gadgetry. Technology is only part of the solution. More than anything, we need a far more comprehensive and consistent approach to species conservation across the nation at all levels if we’re to have any hope of addressing the extinction crisis. Only by ending deforestation and habitat loss, expanding Australia's system of protected areas, addressing invasive predators, and ultimately valuing the myriad benefits of healthy ecosystems, do threatened species like the wiliji really stand a chance.

Finally, with the support of committed people like you, WWF-Australia is continuing to make the very best use of technology and know-how at our disposal. WWF-Australia would also like to acknowledge Ian Sharp. Ian personally backed this drone pilot program, financially and technically. He spent hours poring over the images the cameras collected and developed some software himself to help us process them.

It's further proof of the difference we can achieve, together.