KOALA NEWS & SCIENCE

An informative monthly newsletter about successes & important announcements in koala conservation, and the latest scientific publications about koalas.
January/February 2025
Subscribe here: https://mailchi.mp/808fc4af1ee0/koala-news-science

Native Forest Logging is not sustainable.

Read this excellent submission to the Independent Forestry Panel into the NSW Forestry Industry by Professor Lindenmayer:
https://ipcn-prod.envnsw.cloud/resources/pac/media/files/pac/projects/2024/08/independent-forestry-panel/public-submission-rounds/click-to-view-submissions/david-lindenmayer-id-202079.pdf 
Key Points: 

• “The native forest logging industry is not sustainable in NSW (or indeed anywhere in Australia)”
• “The native forest logging industry is not sustainable because areas that are logged and then regenerated are more flammable, thereby contributing significantly to fire risks.”
• “a key way to reach Australia’s 2030 GHG reduction targets will be to stop native forest logging”
• “Logging not only significantly reduces critical habitat for species such as large old hollow-bearing trees, it also changes the composition of forests that make them unsuitable for leaf-feeding specialist animals like the Koala and Southern Greater Glider “
• “I have made submissions to, or appeared before, 29 inquiries into the native forest logging industry over the past 30 years.”

The independence of the Independent Forestry Panel has been called into question by NEFA and the Greens.  Chair Peter Duncan is a former CEO of Forestry Corporation, Mick Veitch is a former Labor politician, who served as Parliamentary Secretary for Primary Industries. Prof Mary O’Kane is a former NSW Chief Scientist & Engineer, who chaired the 2016 Independent Review into the Decline of Koala Populations in Key Areas of NSW.  Read her report here: https://www.chiefscientist.nsw.gov.au/__data/assets/pdf_file/0010/94519/161202-NSWCSE-koala-report.pdf     Note: none of the 11 recommendations mention forestry.

Public submissions to the Independent Forestry Panel have closed, all those received can be seen here: https://www.ipcn.nsw.gov.au/cases/2024/08/independent-forestry-panel 

2 years after promising a Great Koala NP, it still hasn’t happened 
A great article in globally-respected nature and conservation news MongaBay.
https://news.mongabay.com/2025/02/an-australian-state-promised-to-turn-native-forest-into-a-national-koala-park-its-still-being-logged/

Update from Two Thumbs Wildlife Trust
After being burnt out in the Black Summer, Two Thumbs Wildlife Trust featured on Landline on 23 February.  The program features interviews with James Fitzgerald, Dr Romane Cristecu and Bear, Josey Sharrad, and Darren Grover.
https://www.abc.net.au/news/rural/programs/landline/2025-02-23/koala-recovery:-the-sanctuary-helping-nature/104971642

 

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Latest Koala Science:

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Tacla, P.K., Barth, B.J., FitzGibbon, S.I., Gillett, A.K. and Ellis, W.A., 2025. Patterns of activity and travel by koalas in a disturbed urban landscape in Queensland. Australian Mammalogy, 47(1). https://doi.org/10.1071/AM24044

Habitat loss and fragmentation threaten koala persistence in south-east Queensland, intensifying the challenges posed by climate change and disease to koala survival. Adaptation to modified landscapes may mediate species’ persistence, so we collected location and accelerometery data for 10 koalas in a changing landscape in the Moreton Bay region of Queensland, using remote global positioning system (GPS) collars and manual tracking. We investigated whether ambient temperature influenced how active koalas were and how far they moved, and compared area of use estimated by manual tracking and remote GPS uploads. Accelerometric data showed that koalas were more active at night, and GPS data showed that males moved further than females, but accelerometers measuring activity were not indicative of total distance travelled. Distance moved by koalas per day and night was greatest from May through August and least during March for both males and females. Remotely uploaded GPS locations described a not significantly larger total area of use by each koala compared to manual VHF tracking. There was no general trend in the relationship between day temperature and koala activity or distance moved.

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Kidd, A., Casteriano, A., Krockenberger, M.B., Higgins, D.P. and Wright, B.R., 2024. Koala MHCII association with chlamydia infertility remains equivocal: a need for new research approaches. Scientific Reports, 14(1), p.31074. https://www.nature.com/articles/s41598-024-82217-w

Chlamydiosis is a common infectious disease impacting koalas and is a major cause of population decline due to resulting mortality and infertility. Polymorphisms of major histocompatibility complex (MHC) genes influence chlamydial disease outcomes in several species but koala studies have produced variable results. We aimed to identify the MHC II DAB and DBB repertoire of koalas from Liverpool Plains, NSW, a population heavily impacted by chlamydiosis. We compared variants between two studies, age cohorts and chlamydial infertility groups. Four DBB and eight DAB alleles were identified. The mean number of DAB alleles per individual increased and allele frequencies differed relative to a previous study, however the mean number of DBB alleles per individual decreased generationally, between age cohorts. DAB allele frequencies differed among fertility groups but contributing alleles could not be identified. While there is a likely role of MHCII in the complex pathogenesis of chlamydiosis, this study suggests that single gene association studies are not appropriate for understanding the impact of host genetics on koala chlamydiosis. A shift to larger multivariate studies is required to yield functional information on complex immunological interactions, and to inform targeted koala conservation across its diverse range and host–pathogen–environment contexts.

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Grogan, L.F., Mangan, M.J., Kerlin, D.H., Peel, A.J. and McCallum, H.I., 2025. Evaluating strategies for managing koala chlamydiosis using dynamic models. Biological Conservation, 302, p.110997. https://doi.org/10.1016/j.biocon.2025.110997

Infectious diseases can drive wildlife population declines. However, mitigating disease in free-ranging populations is challenging, particularly for endemic infections and those lacking robust empirical data. Modelling provides a rapid and cost-effective means to examine the key drivers of infection dynamics, the impact of infection on wildlife populations, and the efficacy of potential interventions. Here, we developed a deterministic ordinary differential equation model to study declines in northern koala (Phascolarctos cinereus) populations that are thought to be partly driven by infection with chlamydial bacteria. We developed a further model comparing the effects of potential management strategies on both infection prevalence and population persistence. The dynamics of our base model were consistent with the available empirical data, providing a reasonable foundation for exploring interventions. We identified several key mechanisms and parameters (e.g. density dependence, chronicity of infection/disease, natural immunity and subsequent waning) that led to qualitatively different population outcomes. Base model parameters driving population outcomes included both the disease- and baseline mortality rates, the rate of transition to clinical disease, and the population birth rate. Loss of fertility associated with disease was unexpectedly less important than disease-associated mortality. The most effective management options promoting population persistence included vaccinating animals, reducing other sources of mortality, treating animals, and introducing new animals. Culling was ineffective at suppressing infection prevalence and was always detrimental to population outcomes. With current data, a combined management strategy involving vaccination, reducing other mortality, treating animals and performing occasional translocations from more stable nearby source populations may be most advantageous for promoting persistence of fragmented urban populations.

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Watchorn, D.J., 2025. Social affiliation among sub-adult male koalas in a high-density population. Australian Mammalogy, 47(1). https://doi.org/10.1071/AM24033
Koalas are generally considered to be a solitary species. However, during observations of free-ranging koalas in a high-density population, sub-adult males (3.5–5.5 years) were seen engaging in affiliative behaviours, including grooming, genital sniffing, and vocalising. These interactions were exclusive to males of this age group and are likely a result of the unusually high population density. In such populations, where home range overlap is common, these behaviours may help reduce stress, establish dominance hierarchies, and reduce conflict through familiarisation.

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Yu, T., Blyton, M.B., Koppetsch, B.S., Abajorga, M., Luban, J., Chappell, K., Theurkauf, W.E. and Weng, Z., 2024. The Trajectory of KoRV-A Evolution Indicates Initial Integration into the Koala Germline Genome Near Coffs Harbour. https://doi.org/10.21203/rs.3.rs-5671983/v1

Background Koala Retrovirus-A is a gamma-retrovirus that is spreading across wild koala populations through horizontal and vertical transmission, contributing significantly to genomic diversity across and even within koala populations. Previous studies have estimated that KoRV-A initially integrated into the koala genome less than 50,000 years ago, but the precise origins and the patterns of spread after its endogenization remain unclear.
Results In this study, we analyzed germline insertions of KoRV-A using whole-genome sequencing data from 405 wild koalas, representing nearly the species’ entire geographic range. Our findings reveal an evolutionary trajectory for KoRV-A, suggesting that the initial endogenization might occur near Coffs Harbour on the Mid-north coast of NSW around the middle of the koala’s range. As KoRV-A spread, certain subtypes emerged and became prevalent, two of which recombined with an ancient endogenous retrovirus, PhER, resulting in distinct recombination variants in northern and southern koala populations. Additionally, we identified a geographic barrier north of Sydney, which may have slowed the southward spread of KoRV-A into Sydney and beyond.
Conclusions Our study proposes a comprehensive evolutionary pathway for KoRV-A, beginning with its initial endogenization near Coffs Harbour and highlighting barriers and diversification events that have shaped its distribution and impact on koala populations.

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Church, C., Casteriano, A., Muir, Y.S., Krockenberger, M., Vaz, P.K., Higgins, D.P. and Wright, B.R., 2025. New insights into the range and transmission dynamics of a koala gammaherpesvirus, phascolarctid gammaherpesvirus 2. Scientific Reports, 15(1), p.6136. https://www.nature.com/articles/s41598-025-90626-8

The recent classification of the koala to endangered across most of its range has emphasised the urgent need for enhanced disease surveillance. Little is known about the distribution and clinical significance of phascolarctid gammaherpesvirus 2 (PhaHV-2) outside the Australian states of Victoria and South Australia. PhaHV-2 may have significant impacts on koala wellbeing, justifying investigation into its distribution and impact. To better characterise virus distribution and factors associated with infection, we developed a novel quantitative polymerase chain reaction assay with a high sensitivity, specificity and throughput capacity, to facilitate rapid detection and quantification of PhaHV-2. We applied this assay to 157 predominantly clinically-derived, urogenital swab samples. Results indicated that the distribution of PhaHV-2 extends throughout the endangered New South Wales koala populations. Frequency of detection of PhaHV-2 was highest in South Australia (25%) and lowest in northern Qld (0%) and was more likely in older koalas than younger koalas. We corroborate previous findings of an association with presence of PhaHV-1 and find no evidence to support sex as a predictor for viral presence in clinically-derived samples. The capacity to rapidly detect mucosal shedding of PhaHV-2 will enable rapid isolation of affected individuals and aid further research into the pathophysiological impacts of this virus in koalas and the influence of co-infections.

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Koala Science In Brief

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Petrohilos, C., Peel, E., Silver, L.W., Belov, K. and Hogg, C.J., 2025. AMPed up immunity: 418 whole genomes reveal intraspecific diversity of koala antimicrobial peptides. Immunogenetics, 77(1), p.11. https://link.springer.com/article/10.1007/s00251-024-01368-2

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Law, B., Gonsalves, L., Brassil, T. and Kerr, I., 2025. Appropriate use of acoustics for surveying koalas and interpreting habitat use: a rebuttal to Smith and Pile (2024). Australian Zoologist. https://doi.org/10.7882/AZ.2025.003

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White, S., Ryan, M. and Spencer, R., Understanding the temporal effects of bushfire on the ecological communities in the Sydney basin using the koala (Phascolarctos cinereus) populations as an umbrella species. https://researchers-admin.westernsydney.edu.au/ws/portalfiles/portal/94859866/uws_69976.pdf

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Vuong, T., Chang, M., Palaparthi, M., Howell, L.G., Bonti, A., Abdelrazek, M. and Nguyen, D.T., 2025. An empirical study of automatic wildlife detection using drone-derived imagery and object detection. Multimedia Tools and Applications, pp.1-28. https://link.springer.com/article/10.1007/s11042-024-20522-2

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Robuchon, M., Bernery, C., Cardoso, AC, Dia, C., Courchamp, F., Diagne, C., Gervasini, E., Heringer, G., Pavoine, S., Renault, D. and Rezende, V., Conservation Paradoxes and Challenges in Invasive Alien Species of Economic Concern. Available at SSRN 5047721 . https://dx.doi.org/10.2139/ssrn.5047721

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Leviston, Z., Cohen, R., Gorman, S., Becvarik, Z. and Lal, A., 2025. Willingness to pay for blue-green space and koala habitat protection following a Covid-19 versus bushfire experimental prime. Environmental Research Communications, 7(1), p.011006. https://iopscience.iop.org/article/10.1088/2515-7620/ada878/meta

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Trevathan, J., Tan, WL, Xing, W., Holzner, D., Kerlin, D., Zhou, J. and Castley, G., 2025. A computer vision enhanced IoT system for koala monitoring and recognition. Internet of Things , 29 , p.101474. https://doi.org/10.1016/j.iot.2024.101474

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Chen, C.J., Kimble, B., Van Aggelen, A., Fischer, S., Flanagan, C., Gillett, A., Reed, J., Wakeman, J. and Govendir, M., 2024. Preliminary analyses of tryptophan, kynurenine, and the kynurenine: Tryptophan ratio in plasma, as potential biomarkers for systemic chlamydial infections in koalas. Plos one, 19(12), p.e0314945. https://doi.org/10.1371/journal.pone.0314945

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Previous Koala News & Science here: https://www.wildkoaladay.com.au/koala-news-science/koala-news-science-nov-december-2024/
Written by Janine Duffy President, Koala Clancy Foundation.
with support from Cheryl Egan, Organiser, Wild Koala Day.
Please send your important news & publications to president@koalaclancyfoundation.org.au before 29th of each month for possible inclusion.