Listening up for Koalas

By Andrew Howe, Senior Field Ecologist, Nahrain John, Communications Associate

The Koala (Phascolarctos cinereus) is an icon of Australian nature, ubiquitous in tourism campaigns and popular culture. Yet, ironically, these well-known tree-climbing marsupials are a lot harder to find in the bush. When it comes to Koalas on Australian Wildlife Conservancy’s (AWC) Curramore and Mount Zero-Taravale Wildlife Sanctuaries in Queensland, incidental sightings, images on camera traps, as well as scats and scratches, confirm they persist, but we don’t know much else about the status or trends of these iconic species.

Spending most of their time motionless high in the canopy, Koalas pose a real challenge for ecologists monitoring them, especially across the steep terrains of Curramore and Mount Zero-Taravale. Now, a new approach that relies on the Koalas’ repertoire of growls, grunts and barks offers the prospect of unlocking important data essential to the protection of this endangered species on AWC sanctuaries.

imageBROKER/Alamy Stock Photo

For most animal species, conventional survey methods that use baited cage traps or camera traps are an effective means of surveying at scale (capturing data on a large number of species over vast areas). However, given Koalas spend most of their time off the ground and are not attracted to food bait, these techniques are not effective. In the past, ecologists have explored other methods to survey at scale, including spotlighting transects and working with specially-trained detection dogs that sniff out fresh scat and the scent of animals up above. In 2021, four individual Koalas were observed during spotlighting transects across the 196-hectare Curramore, which was identified to be a part of a Koala Priority Area by the Queensland Government in 2020. Detection dog surveys also picked up an increase in Koala activity on the property from 2015 to 2022.

While these surveys offer an intriguing glimpse into Koalas on Curramore, the picture remains incomplete. The AWC team is eager to establish better understanding of the distribution and population density of Curramore’s resident Koalas, and to investigate any threats. Across the 58,000-hectare Mount Zero-Taravale, targeted monitoring has not yet been undertaken, but incidental sightings and images on camera traps indicate a persisting population on the sanctuary.

Wayne Lawler/AWC

Continuing large-scale monitoring
Thanks to a $179,211 contribution from the federal government’s Koala Conservation and Protection Grant, AWC is hoping to learn a lot more about its Koala populations by deploying bioacoustic monitors across suitable Koala habitat at the two sanctuaries. By high-tech ‘listening’, ecologists hope to conduct larger-scale monitoring of the species and establish baseline data about the presence and abundance of Koalas on sanctuary. At Curramore, ecologists will also use thermal drone surveys to compare the effectiveness of both technologies.

Andrew Howe, AWC Senior Field Ecologist who is leading the bioacoustic research at Curramore and Mount Zero-Taravale, said that although Koalas are such a famous Australian species, very little is known about their ecology, distribution and threats in the northern extent of their range.

“Curramore Wildlife Sanctuary is the largest nature refuge on the Sunshine Coast and is a geographically significant habitat corridor linking habitat from Maleny National Park in the west to other nature refuges and Koala habitat in the east,” Andrew explained. “The sanctuary could potentially sustain an important population in the context of the broader region – but we need to do research to better understand local population dynamics.”

“Meanwhile, at Mount Zero-Taravale, monitoring will form the baseline for Koala population estimates on the property. We plan to undertake ongoing monitoring as part of AWC’s Ecohealth program which will include monitoring the species every two-to-five years to determine if the populations are stable, increasing or decreasing. If the population is decreasing, we will then undertake specific targeted research to determine what is driving the decline and then mitigate any threats as much as possible.”

AWC is embracing innovative technologies to enhance our ecological monitoring and conservation work. Bioacoustic monitoring is a relatively new tool that is increasingly being utilised across AWC sanctuaries to complement conventional survey methods. In the north-east region, AWC is using bioacoustics to survey for microbats at Mount Zero-Taravale and Curramore, and the Magnificent Brood Frog (Pseudophryne covacevichae) at Mount Zero-Taravale. Acoustic recorders are useful to monitor cryptic species that vocalise during the breeding season, or which are most active at night, like frogs. The devices can be left out in the field for extended periods of time, allowing AWC ecologists to collect a high volume of quality data more efficiently than ever before.

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