KOALA NEWS & SCIENCE
An informative monthly newsletter about successes & important announcements in koala conservation, and the latest scientific publications about koalas.
November/December 2024
Subscribe here: https://mailchi.mp/808fc4af1ee0/koala-news-science
Xmas and festive season events that support koalas:
Koala Advent Calendar Challenge by Koala Action Gympie Region: https://www.facebook.com/koalagympie
25K by 2025 fundraiser by Koala Clancy Foundation: https://www.koalaclancyfoundation.org.au/donate/
500,000 reasons for hope fundraiser by Bangalow Koalas: https://fb.watch/wxXRDtCbEz/
Make a Pledge for Koalas by Port Macquarie Koala Hospital: https://www.facebook.com/reel/567787442722060
Become a Friend of the Northern Rivers Koala Hospital: https://friendsofthekoala.org/friends-of-the-northern-rivers-koala-hospital/
EVENTS:
12 December – 9 February: Koala Photographic Exhibition, Port Macquarie by Koala Hospital Port Macquarie https://fb.me/e/5eBHxmtoU
20 December: Twilight Markets Christie Beach SA by Unconditional Love All Creatures Great & Small: https://www.facebook.com/share/p/12KyVPTFa4S/
9, 16, 23 January: Koala Quest, Port Macquarie by Koala Conservation Australia (Port Macquarie Koala Hospital) https://www.facebook.com/share/1KSSKs8y3u/
Koala Adoptions for Xmas:
Southern Koala & Echidna Rescue, SA: https://www.sker.org.au/sponsorship/wildlife-sponsorship
Koala Gardens at Tuckurimba, NSW: https://koalagardens.net.au/product-category/adoptions/
Port Stephens Koala Hospital, NSW: https://portstephenskoalas.com.au/adopt/
Friends of the Koala, Lismore NSW: https://friendsofthekoala.org/save-koalas/adopt-a-koala/
Beautiful content to share:
Koalas of the Gympie Region – too precious to lose: https://arcg.is/14jbym
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Latest Koala Science:
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Tran, H.N. and Maron, M., Biodiversity offset conditions contributing to net loss of koala Phascolarctos cinereus habitat. Conservation Science and Practice, p.e13271. https://doi.org/10.1111/csp2.13271
Australia’s offset framework requires that permitted development impacts on nationally threatened species should be fully counterbalanced using biodiversity offsets. The current offsets framework was established in 2012, the same year that the iconic koala Phascolarctos cinereus was listed as threatened. We examined every development impact on koala habitat that was permitted under national biodiversity laws (the EPBC Act 1999) from 2012 until the end of 2021, shortly after which the koala was uplisted from vulnerable to endangered (n = 98). We analyzed the application of the national environmental offset framework in each case. In this period, more than 25,000 hectares of koala habitat were approved for removal, most in the state of Queensland (96%) and for mining (76%). Although most clearing of koala habitat is attributable to agricultural activity and ostensibly requires approval under the EPBC Act, we found zero referrals for agricultural clearing. A total of 62 projects included offset requirements for koalas, but for only 14 projects could we find details used in the offset calculation. All but one appeared to include implausibly optimistic assumptions or logical errors that inflated the estimated benefit from the offset. After modifying the calculations to align with best practice guidance, we found only two of the 14 projects were likely to fully offset their impacts on koalas (average 55% of impact offset). The most common issues were overestimated benefits from averted losses and double-counting of benefits. We conclude transparency around offset requirements is generally poor, and most biodiversity offsets for koalas are unlikely to fully counterbalance losses. Despite sound, long-established policy, poor implementation means that even offsets for impacts on a highly valued species, for which offsets are ecologically plausible, are prone to failure.
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Premachandra, H.K.A., Piza-Roca, C., Casteriano, A., Higgins, D.P., Hohwieler, K., Powell, D. and Cristescu, R.H., 2024. Advancements in noninvasive koala monitoring through combining Chlamydia detection with a targeted koala genotyping assay. Scientific Reports, 14(1), pp.1-8. https://www.nature.com/articles/s41598-024-76873-1
Wildlife diseases are major players in local and global extinctions. Effective disease surveillance, management and conservation strategies require accurate estimates of pathogen prevalence. Yet pathogen detection in wild animals remains challenging. Current gold standards often require samples collected through veterinary examination, but this method is costly, intensive, invasive, and requires specialised staff and equipment. Collection of non-invasive samples, such as scats, is an effective monitoring tool which can be deployed at large scale, as scats contain DNA of both host and pathogens. The koala (Phascolarctos cinereus) is listed as ‘endangered’ under the EPBC Act 1999, with chlamydial disease representing a major threat. Here, we present a new approach that combines restriction-enzyme associated sequencing and targeted-sequence-capture genotyping, namely DArTcap, to detect Chlamydia pecorum in koala scats. We found this method has similar accuracy to current gold standards (qPCR of swab samples), with a sensitivity of 91.7% and a specificity of 100%. This method can be incorporated into existing koala genetic studies using marker panels, where population attributes can be estimated alongside C. pecorum presence, using the same scat samples, with the option to add further markers of interest. Such a one-stop-shop panel would considerably reduce processing times and cost.
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Abajorga, M., Yurkovetskiy, L. and Luban, J., 2024. piRNA Defense Against Endogenous Retroviruses. Viruses, 16(11), p.1756. https://doi.org/10.3390/v16111756
Infection by retroviruses and the mobilization of transposable elements cause DNA damage that can be catastrophic for a cell. If the cell survives, the mutations generated by retrotransposition may confer a selective advantage, although, more commonly, the effect of new integrants is neutral or detrimental. If retrotransposition occurs in gametes or in the early embryo, it introduces genetic modifications that can be transmitted to the progeny and may become fixed in the germline of that species. PIWI-interacting RNAs (piRNAs) are single-stranded, 21–35 nucleotide RNAs generated by the PIWI clade of Argonaute proteins that maintain the integrity of the animal germline by silencing transposons. The sequence specific manner by which piRNAs and germline-encoded PIWI proteins repress transposons is reminiscent of CRISPR, which retains memory for invading pathogen sequences. piRNAs are processed preferentially from the unspliced transcripts of piRNA clusters. Via complementary base pairing, mature antisense piRNAs guide the PIWI clade of Argonaute proteins to transposon RNAs for degradation. Moreover, these piRNA-loaded PIWI proteins are imported into the nucleus to modulate the co-transcriptional repression of transposons by initiating histone and DNA methylation. How retroviruses that invade germ cells are first recognized as foreign by the piRNA machinery, as well as how endogenous piRNA clusters targeting the sequences of invasive genetic elements are acquired, is not known. Currently, koalas (Phascolarctos cinereus) are going through an epidemic due to the horizontal and vertical transmission of the KoRV-A gammaretrovirus. This provides an unprecedented opportunity to study how an exogenous retrovirus becomes fixed in the genome of its host, and how piRNAs targeting this retrovirus are generated in germ cells of the infected animal. Initial experiments have shown that the unspliced transcript from KoRV-A proviruses in koala testes, but not the spliced KoRV-A transcript, is directly processed into sense-strand piRNAs. The cleavage of unspliced sense-strand transcripts is thought to serve as an initial innate defense until antisense piRNAs are generated and an adaptive KoRV-A-specific genome immune response is established. Further research is expected to determine how the piRNA machinery recognizes a new foreign genetic invader, how it distinguishes between spliced and unspliced transcripts, and how a mature genome immune response is established, with both sense and antisense piRNAs and the methylation of histones and DNA at the provirus promoter.
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Al-Shimaysawee, L.A., Finn, A., Weber, D., Schebella, M.F. and Brinkworth, R.S., 2024. Evaluation of Automated Object-Detection Algorithms for Koala Detection in Infrared Aerial Imagery. Sensors (Basel, Switzerland), 24(21), p.7048. https://doi.org/10.3390/s24217048
Effective detection techniques are important for wildlife monitoring and conservation applications and are especially helpful for species that live in complex environments, such as arboreal animals like koalas (Phascolarctos cinereus). The implementation of infrared cameras and drones has demonstrated encouraging outcomes, regardless of whether the detection was performed by human observers or automated algorithms. In the case of koala detection in eucalyptus plantations, there is a risk to spotters during forestry operations. In addition, fatigue and tedium associated with the difficult and repetitive task of checking every tree means automated detection options are particularly desirable. However, obtaining high detection rates with minimal false alarms remains a challenging task, particularly when there is low contrast between the animals and their surroundings. Koalas are also small and often partially or fully occluded by canopy, tree stems, or branches, or the background is highly complex. Biologically inspired vision systems are known for their superior ability in suppressing clutter and enhancing the contrast of dim objects of interest against their surroundings. This paper introduces a biologically inspired detection algorithm to locate koalas in eucalyptus plantations and evaluates its performance against ten other detection techniques, including both image processing and neural-network-based approaches. The nature of koala occlusion by canopy cover in these plantations was also examined using a combination of simulated and real data. The results show that the biologically inspired approach significantly outperformed the competing neural-network- and computer-vision-based approaches by over 27%. The analysis of simulated and real data shows that koala occlusion by tree stems and canopy can have a significant impact on the potential detection of koalas, with koalas being fully occluded in up to 40% of images in which koalas were known to be present. Our analysis shows the koala’s heat signature is more likely to be occluded when it is close to the centre of the image (i.e., it is directly under a drone) and less likely to be occluded off the zenith. This has implications for flight considerations. This paper also describes a new accurate ground-truth dataset of aerial high-dynamic-range infrared imagery containing instances of koala heat signatures. This dataset is made publicly available to support the research community.
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Koala Science In Brief:
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Johnson, D.C., Srivastava, S.K. and Shapcott, A., 2024. Forest Fire Severity and Koala Habitat Recovery Assessment Using Pre-and Post-Burn Multitemporal Sentinel-2 Msi Data. Forests 2024, 15, 1991 [online] https://doi.org/10.3390/f15111991
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Natsuyama, Y., Shimada, K., Nakamura, Y., Kawata, S., Yakura, T., Li, Z.L., Miyaso, H., Yi, S.Q. and Itoh, M., 2024. Anatomical study of brachial plexuses of a koala, a Tasmanian devil, and a common ringtail possum. Folia Morphologica. https://doi.org/10.5603/fm.102687
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Cui, J., Batley, K.C., Silver, L.W., McLennan, E.A., Hogg, C.J. and Belov, K., 2025. Spatial variation in toll-like receptor diversity in koala populations across their geographic distribution. Immunogenetics, 77(1), p.5. https://link.springer.com/article/10.1007/s00251-024-01365-5
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Saltré, F., Peters, K., Rogers, D., Chadoeuf, J., Weisbecker, V. and Bradshaw, C., 2024. Balancing overpopulation and conservation targets to optimize koala management strategies. https://www.authorea.com/doi/full/10.22541/au.173271483.38842713
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Previous Koala News & Science here: https://www.wildkoaladay.com.au/koala-news-science/october-2024/
Written by Janine Duffy President, Koala Clancy Foundation.
with support from Cheryl Egan, Organiser, Wild Koala Day.
Please send your positive, important news & publications to president@koalaclancyfoundation.org.au before 29th of each month for possible inclusion.