Koala research and advice

Expert panel

An expert panel, comprising koala and forestry experts, supports the program to deliver robust and scientifically credible research. The members include:

• Mr Peter Cochrane (Chair (Assistant Commissioner, Natural Resources Commission)
• Dr Desley Whisson (Senior Lecturer in Wildlife and Conservation, School of Life and Environmental Sciences, Deakin University)
• Dr Alistair Melzer (Adjunct Research Fellow, Koala Research CQ, School of Medical and Applied Sciences, Central Queensland University)
• Prof Patrick Baker (Professor of Silviculture and Forest Ecology, School of Ecosystem and Forest Sciences, University of Melbourne)
• Dr Louise Pastro (Principal Policy Officer, Conservation Policy and Strategy, Department of Climate Change, Energy, the Environment and Water (DCCEEW))
• Dr Tim Jessop (Team Leader – Koala Monitoring and Research, Conservation and Restoration Science, Department of Climate Change, Energy, the Environment and Water (DCCEEW)).

Koala response to timber harvesting (2019-22)

• Research report (updated December 2022)
• Revised research program plan (revised September 2020)
• Research note (May 2023)

Under the previous NSW Koala Strategy (2018-21), we delivered independent research to better understand how koalas are responding to harvesting in state forests on the NSW north coast.

The research, carried out by eminent scientific researchers from the Australian National University, Western Sydney University, and the Department of Primary Industries Forest Science Unit, assessed koala and habitat responses to selective harvesting in north coast state forests.

This is the most comprehensive research conducted to date in NSW on how koalas and their habitat respond to harvesting. The researchers worked in collaboration to investigate koala movement, occupancy, density, diet and the nutritional quality of koala habitat on north coast state forests.

Overall, the research found selective harvesting did not adversely impact koala density at research sites, nor the nutritional quality of koala habitat. This suggests that at these sites, koala protections and wider landscape protections codified the Coastal Integrated Forestry Operations Approval (Coastal IFOA) are effectively mitigating the risks from selective harvesting to date.

Research into koala diets showed that individual koalas have different dietary preferences, which may be influenced by the available food resources and local conditions. The koalas in the study consumed a range of tree species, although they did show a preference for certain species.

Other research insights include:

• koala density was higher than anticipated in the surveyed forests and was not reduced by selective harvesting
• koala density was mostly similar between state forest and national park sites that had similar forest types, and a mix of old growth and regrowth from historical harvesting
• tree species composition – not tree size – is the key determinant of habitat nutritional quality for koalas and, therefore, the density of koalas that can be supported
• selective harvesting at the treatment sites did not significantly change canopy tree species composition and, therefore, is not expected to impact on nutritional quality of koala habitat
• tallowwood (Eucalyptus microcorys) and small-fruited grey gum (E. propinqua) were confirmed to be important diet species, in alignment with the Coastal IFOA koala browse tree list
• spotted gum (Corymbia maculata) and ironbarks (E. paniculata, E. siderophloia), while not included on the Coastal IFOA browse tree list were browsed by koalas to a considerable extent.

Our report recommends opportunities to improve outcomes for koalas, including reviewing koala browse trees listed under the Coastal IFOA and potential economic impacts of any recommended changes. This review can leverage expert advice provided to the Commission on our work to verify and improve koala prescription maps and underlying models under the Private Native Forestry codes.

The report also recommends improving the knowledge base with ongoing long-term monitoring to evaluate the effectiveness of Coastal IFOA rules to meet their intended outcomes, including those for koalas. This is being implemented as part of our Coastal IFOA monitoring program.

Researchers engaged under our Koala Research Program will publish their research in peer-reviewed scientific journals.

The results on koala occupancy and density in response to harvesting were recently published in the Nature Portfolio of Journals titled Regulated timber harvesting does not reduce koala density in north-east forests of New South Wales.

Research related to this research program has been published in Ecology and Evolution titled Broad-scale acoustic monitoring of koala populations stability, but varying bellow rate, in the face of major disturbances and climate extremes.

Koala and habitat response post-wildfires at research sites

• Summary paper - Koala and habitat response after wildfire (November 2022)
• Research note - Koala and habitat response after wildfires (June 2023)
• Report - Effects of forest harvesting on koala habitat nutritional quality (July 2021)

In August 2020, the NSW Forest Monitoring Steering Committee approved funding to investigate the impact of the 2019-20 wildfires on koalas and their habitat. This leveraged existing research from this program in a cost-effective way and provides priority information for decision making and community.

We have now published a summary paper and a research note summarising the researcher findings. Read more here.

Researchers have provided a report detailing their results on koala habitat nutritional quality. The addendum to this report (on page 35) also contains the results from the research on wildfire impacts to koala habitat.

This research has been published in Global Ecology and Biogeography titled Fire severity and its local extent are key to assessing impacts of Australian mega-fires on koala (Phascolarctos cinereus) density.

Coastal IFOA koala browse tree review

The NSW Forest Monitoring Steering Committee with support from experts will review a number of species listed under the Coastal IFOA koala browse tree list. This will ensure the highest value browse species are retained, with support from experts for the upper and lower north-east subregion. This work was recommended by the Commission in its final research report on koala response to timber harvesting.

Read more here.

Private native forestry koala mapping updates

The NSW Forest Monitoring Steering Committee is overseeing the validation and improvement to the interim PNF Koala Prescription Maps for each Private Native Forestry region in NSW. The work will independently review models that underpin existing maps and undertake comprehensive on-ground validation.

This is being undertaken with agency scientists and experts who are providing advice on koala habitat, habitat modelling and ground-truthing, including preferred koala browse tree species and their distributions.

Read more here.

Koala and fauna monitoring on coastal state forests

We are independently overseeing a monitoring program with the NSW Forest Steering Committee to ensure the ongoing effectiveness of the Coastal IFOA in achieving its objectives and outcomes.

The program will estimate the trends in occupancy of focal species, such as koalas and other arboreal mammals, hollow-dependant bats, nectivores, ground-dwelling mammals and forest owls.

This work builds on previous monitoring by NSW Forestry Corporation and the NSW Department of Primary Industries, including annual monitoring of koala occupancy in the hinterland forests of northeast NSW since 2015.

Read more here.

Exploring drone-based koala surveys

• Options paper - Drone-based monitoring (April 2024)

Dr Ryan Witt (University of Newcastle) was engaged to explore the use of drone-based surveys to assess koala population density changes in response to timber harvesting.

Drones fitted with thermal cameras have been effective in surveying for mammals – especially those found in terrain difficult to access by vehicle or foot. However, this type of monitoring has not previously been used to assess the effects of a specific disturbance on a koala population. Dr. Witt’s options paper identified a Before-After-Control-Impact Paired Series (BACIPS) design using drones as an optimal approach, but noted there are significant resource demands, limitations, and costs associated with this type of monitoring.

The expert panel considered the options paper and found there was scientific merit to the proposed approach. However, the cost to implement the approach meant it could not be resourced within the available research budget. In response, the expert panel suggested alternative research that could be funded under the program. The program will instead proceed with a combination of acoustic surveys and DNA analysis of koala scats to assess koala population responses to harvesting.

More details about the koala research program can be found in the research program plan.