Reg Mombassa on koalas

We asked Reg, 'Why the koala?'

"I frequently use the koala in my pictures to indicate an Australian location, as it is a readily identifiable iconic animal peculiar to this country. The koala is under threat of extinction because of climate change and habitat destruction by logging and land clearing. It is more threatened than its bigger and faster cousin the kangaroo. So, it is appropriate that I use the koala in my eco related pictures.

"If koalas were a minority species of humans threatened with extinction or relocation they would be fighting for their survival. Lucky for us koalas are not human!

"The onwards and upwards koala was designed to cheer up higher school certificate students at the beginning of the pandemic."—Reg Mombassa

Limited edition 'Onward And Upward!' koala tee

Artist Reg Mombassa shared this koala design with Wilderness Society for a special new T-shirt.
We thank Reg for his beautiful work and his ongoing generosity and dedication to the protection of the natural world. Purchasing this tee helps support the Wilderness Society.
(Adult and kid sizes available)

Keeping an eye on koalas

We spoke with Dr Kellie Leigh, the CEO of Science for Wildlife on the important research her team has been conducting into koala populations and the habitats they use.

What is it about koalas that fascinates you?

I never had a dream of becoming a koala researcher. I first became involved because there were some very clear gaps in koala conservation. When I chat with colleagues about what needs to happen for koala conservation to be properly informed and effective, we're often surprised and think: 'hasn’t anyone done that yet?'. Coming back from a decade of work in Africa, I didn’t expect to be working with such an iconic species, I figured koalas must have been well studied and well looked after. The fact they haven’t has been my biggest motivator. It’s a bit embarrassing as an Australian too.

Koalas are also what is known as an umbrella species; they rely on a huge diversity of eucalypt forests for their survival and if we protect those forests that benefits a range of other species. So while koala conservation is a single species project, it gives us some extra bang for the conservation buck and that was a strategic choice behind starting to work with them.

Tell us about your recent expedition—what were you doing and where?

We’re expanding our work documenting koala populations in and around the Greater Blue Mountains World Heritage Area. We’ve been receiving sighting reports of koalas for some years from around the Lue area, and we are excited to have finally landed some funding (a Commonwealth Saving Koala Fund grant) to start surveys up that way. Our team, including koala detection dog and friendly ambassador Groot, headed up that way to Rylstone and Mudgee, to meet with community members, the local Landcare group, Traditional Owners, and also staff from the local National Parks and Wildlife Service and Council, to get an idea of what’s going on.

There have been an increasing number of koala records, and we were delighted that everyone is really supportive of our plans to get a better handle on the size and distribution of the koala population and document their preferred habitats.

What can you tell us about some exciting recent discoveries of new populations and growing populations too?

It's true there is a very good news story to be told. The overall picture for koalas is not good, with general decline across their range in NSW, QLD and the ACT and their uplisting as an endangered species in these states, so there is a lot to be concerned about. However, where we have growing koala populations it is important to learn from that, and to make sure these areas of hope are a high priority for conservation management.

That’s the story of the koalas we have been documenting in and around the Greater Blue Mountains World Heritage Area (GBMWHA), over the last 10 years. We’re finding koalas spread over a large area, using tree species and habitats we didn’t know they could utilise, on relatively poor soil types. They have high genetic diversity which is important to conserve, and we’re also finding chlamydia-free populations on the western side of the Great Dividing Range. We’re learning so much from them, and they’re doing such interesting things, we call them the “rule breaking” koalas.

The discovery last year of a healthy population of koalas living in Coolah Tops National Park in Central West NSW was more really good news. It wasn’t completely surprising because one thing we have found is that if you don’t look, you don’t find. Koalas can be very cryptic in some areas, particularly where the trees are tall and/or terrain is rugged and remote, and the fact they are not seen very much doesn’t mean they are not there. It’s encouraging that more survey effort is happening now, to uncover more koala populations.

Do the new and growing populations give you hope for the future of koalas?

Yes, absolutely. In recent decades conservation efforts have focused on areas with good soil types and high densities of koalas, especially close to the coast. But when you think back to the fur trade days in the late 1800s and early 1900s, when millions of koalas were shot, those sorts of numbers indicate koalas were widespread. It makes sense that they are more generalist than recent science suggests. There were historical records of people hunting koalas on the western and eastern edges of the GBMWHA back in those days.

So the good news is that, as we’ve been discovering, there are many more habitat types that can support koalas than everyone thought, so there’s more potential koala habitat for them to expand into and to protect. Prior to our work, nobody thought the primarily sandstone country of the GBMWHA could support decent numbers of koalas. But our work to date has uncovered not just hundreds, but thousands of koalas.

That doesn’t mean that koalas are not in real trouble in many other places, where removal of habitats is having a massive impact along with other threats. The koalas we’re working with are also at risk from disease, fire and climate change. So there is a lot to do to ensure their future, but these stories of hope are really motivating.

Climate change is a massive threat to koalas, how can the Blue Mountains koala populations you work with help to mitigate the threat of climate change for koalas?

That is also a question we are trying to answer. There are indications that the GBMWHA may be a climate refuge for koalas and other species. It has a wide range of habitats and microclimates and while, for example, the general weather pattern might be very hot and dry, there are likely to be areas in the mountains that are cooler and wetter. We need to know if koalas use these. So, we have a study underway with temperature monitors out in the landscape, and on koalas, and we’re looking to see how koalas use the landscape under different weather conditions. For example, do they move into gullies in hot weather, or do they just move into a denser canopy shade tree up on the ridge?

Obtaining this information will also help us to future-proof habitat restoration efforts beyond our study sites.

Why is it important to have large, intact habitat for koalas like that in the Blue Mountains and the proposed Great Koala National Park in Northern NSW?

Conserving habitats with appropriate scale and connectivity is critical for all species. There is a phenomenon called the 'edge effect' that has a big impact. For example, if you have a population of koalas living in a small national park or reserve, some of them are going to move into surrounding areas where they encounter more threats, such as vehicle strike and dog attacks.

Habitat fragmentation means they are likely to have to move greater distances to find good food trees. Koalas have a low-energy diet of eucalypt leaves, they sleep up to 20 hours per day, which is when their bodies are using a lot of energy to digest food that is toxic to most other animals. Having to move further to find food can impact their health; from making them more susceptible to disease, to potentially causing starvation if they can’t find enough decent food. It’s the human equivalent of having to run a marathon to get a meal. You can’t do that everyday and survive, you’re burning more energy than you’re consuming.

This all results in higher mortality rates in these edge areas outside of the reserves. It can drain the overall numbers of a koala population; in ecological terms it is known as a sink. Effective conservation requires a protected area that is big enough to sustain a whole population of koalas within it. Given how endangered koalas are we need to enable population growth, not just maintain numbers, which means the areas and their connectivity need to be even larger. That’s why the GBMWHA and other large protected areas are so vital.

Find out more about the work of Science for Wildlife.

A portrait of a koala by David Moore, 1976

One Australian legend photographs another. We thank the David Moore estate for this photograph.

© Lisa, Michael, Matthew and Joshua Moore, image courtesy davidmoorephotography.com.au