KOALA NEWS & SCIENCE
An informative monthly newsletter about successes & important announcements in koala conservation, and the latest scientific publications about koalas.
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Logging suspended in Newry NSW 26 August
A suspension of logging in one of the forests proposed to form part of the Great Koala NP has been extended until 5 September. The action was brought before the Land & Environment Court by Gumbaynggirr Elders on the grounds of concerns for Aboriginal cultural sites.
Mounting pressure on NSW government over Great Koala NP ‘breach of trust’:
The Guardian 12 August: https://www.theguardian.com/australia-news/2023/aug/12/nsw-labor-accused-of-fundamental-breach-of-trust-over-logging-in-promised-koala-national-park
NPA NSW 7 August: https://npansw.org.au/2023/08/07/forestry-corporation-shows-blatant-disregard-for-integrity-of-great-koala-national-park/
Sydney Morning Herald 2 September: https://www.smh.com.au/environment/conservation/minds-were-blown-these-scientists-were-stunned-at-what-s-happening-on-the-nsw-north-coast-20230831-p5e11w.html
The Project 4 September: https://youtu.be/6fhFY52oKGE?si=JZlWNiqYvzuaJODq
Asia Pacific Report 26 August: https://asiapacificreport.nz/2023/08/26/australian-fight-to-protect-koala-habitats-in-northern-nsw-heats-up/
Inverell Times 19 August: https://www.inverelltimes.com.au/story/8314901/nsw-govt-under-fire-as-trees-fall-in-koala-heartland/
The Border Mail 13 August: https://www.bordermail.com.au/story/8306729/border-rally-hears-government-far-too-slow-to-protect-koalas/
360,000 year old fossil koala tooth found in Central QLD 2 September
The fossil tooth was found at Capricorn Caves as part of Big Science Adventure and is being examined by Queensland Museum Palaeontologists, Dr Scott Hocknull and Rochelle Lawrence
Fines for dog attacks on koalas in Gold Coast 26 August
Gold Coast council has introduced laws to impose fines on residents whose dogs cause injury to people or wildlife, and to encourage more wildlife-friendly backyards.
Rallies for forests Australia-wide 12 August
Rallies calling for an end to native forest logging were organised by Bob Brown Foundation, in Melbourne, Sydney, Perth, Brisbane and Hobart.
Koala photo competition seeks to learn more about koalas in Burnett, QLD 11 August
The competition run by Burnett Catchment Care Association is seeking photos and past and present observations from across the region. The competition closes on 30 November.
New koala drone survey begins Port Stephens NSW 10 August
University of Newcastle scientists Dr Ryan Witt and PhD candidate Shelby Ryan will survey over 130 sites for koalas in and around Port Stephens over the next few months.
Bushfire survivor seen with 2nd joey NSW 4 September
Koala “Ember”, who was rehabilitated by Friends of the Koala & IFAW after being injuried in the fires in Whiporie, northern NSW in 2019, has been spotted with her second joey since the fires.
Host a Picnic For Nature NSW 21 October
NCC NSW Nature Conservation Council of NSW are encouraging groups all over NSW to host a picnic on 21 October. Register here: https://www.nature.org.au/picnic
Small win for koalas around Joyner, QLD 22 August
A proposal for a shopping centre development on a large, forested block at Joyner, Brisbane has been refused.
Latest Koala Science:
Campbell, Y., Palmieri, C., Pagliarani, S., Gordon, J. and Johnston, S., 2023. The koala (Phascolarctos cinereus) prostate: a comprehensive histological and immunohistochemical investigation. Biology of Reproduction, p.ioad098. https://doi.org/10.1093/biolre/ioad098
The prostate of the koala (Phascolarctos cinereus), and of marsupials more generally, is the primary contributor of seminal fluid, yet comparatively little is known about its microanatomy or biochemistry. This study explored evidence of parenchymal segmentation of the koala prostate. The prostate of three sexually mature koalas were processed for histopathology, histochemistry (Masson’s trichrome, Alcian Blue, periodic acid Schiff staining), and immunohistochemistry using basal (tumor protein 63, cytokeratin 14) and luminal (cytokeratin 8/18, prostate specific antigen, androgen receptor) markers. Results confirmed clear segmentation of the koala prostate into three zones, anterior, central, and posterior, characterized by differences in the proportion of glandular tissue, as well as the thickness of collagen fibers; there were also distinct differences in the secretions produced in each zone. Based on immunohistochemistry, the koala prostate showed evidence of both basal proliferative and luminal secretory cells. The ratio of cell types varied across the three segments, with the central segment housing the highest density of basal cells. Globular bodies produced in the anterior zone were shown to possess the same markers as those described for human prostasomes. This study is the first to comprehensively document the marsupial prostate in terms of microanatomy and corresponding immunohistochemistry. While further biochemical analysis, such as proteomics of each segment will better define the relative functions of each tissue, the data presented here are consistent with the hypothesis that the koala prostate potentially represents an example of an ontological stage in the evolutionary differentiation of male eutherian accessory glands.
Swaffield, M.J., Liberts, M., Gillett, A.K. and Moses, P.A., 2023. Refractory otitis media and otitis externa in a koala (Phascolarctos cinereus) treated with total ear canal ablation and lateral bulla osteotomy. Australian Veterinary Journal. https://doi.org/10.1111/avj.13281
Background To the authors’ knowledge, this is the first report fully describing the surgical and medical management of otitis media and otitis externa in the koala (Phascolarctos cinereus) treated by total ear canal ablation and lateral bulla osteotomy.
Case Report An adult male koala captured as part of a monitoring project in South East Queensland was diagnosed with chlamydial cystitis. Purulent discharge from the right ear was also observed; diagnostic imaging was consistent with otitis media and otitis externa. Yokenella regensburgei was repeatedly cultured from the site. Clinical signs resolved with topical antibiotic therapy; however, recrudesced following cessation of antibiotics. A total ear canal ablation and lateral bulla osteotomy was performed, followed by an extended period of systemic antibiotic therapy. Mild facial nerve paresis was observed for 4 weeks postoperatively and resolved spontaneously. The koala remained clinically healthy for the 6 months it was monitored following release.
Conclusion Total ear canal ablation combined with lateral bulla osteotomy appears to be an appropriate surgical intervention for otitis media combined with otitis externa refractory to medical management in the koala. Transient postoperative facial nerve paresis is a possible complication, as documented in other species. To the authors’ knowledge this is the first case of Yokenella regensburgei infection outside of humans and American alligators (Alligator mississippiensis); the clinical significance of this pathogen in the koala remains unknown.
Simpson, S.J., Higgins, D.P., Timms, P., Mella, V.S., Crowther, M.S., Fernandez, C.M., McArthur, C., Phillips, S. and Krockenberger, M.B., 2023. Evaluation of the efficacy of a synthetic peptide Chlamydia pecorum Major Outer Membrane Protein vaccine as a management tool in a koala (Phascolarctos cinereus) population severely affected by chlamydiosis. https://doi.org/10.21203/rs.3.rs-3098357/v1
Chlamydiosis is a significant disease affecting Eastern Australian koala (Phascolarctos cinereus) populations, impacting individual animal welfare and fecundity and therefore influencing population dynamics. The aim of this study was to investigate the effect of a synthetic peptide vaccine based on 4 components of the Chlamydia pecorum Major Outer Membrane Protein (MOMP), over an 18-month period in a koala severely impacted by chlamydiosis. Wild koalas were recruited into a vaccination or a placebo treatment group on a random allocation, then followed through a period of 18 months, with recapture at 6 monthly intervals. Vaccination did not alter clinical disease expression or chlamydial shedding from the ocular or urogenital sites. Vaccination did not stimulate a significant plasma anti-MOMP IgG response, when compared to the placebo group. There was no significant effect of vaccination on IFN-γ and IL-17A mRNA expression of peripheral blood lymphocytes when stimulated with rMOMP. We have demonstrated that a synthetic peptide vaccination against chlamydiosis is not an effective management tool in a koala population with a high prevalence of C. pecorum infection and related disease. The lack of antigenic response found in this study suggests that further research utilising a larger, full-length antigen is an avenue worth investigation if we are to consider vaccination as a part of a management strategy in diseased koala populations.
Taggart, P., Sloggett, B., Madani, G., Phalen, D., Cullen, D., Madden, K. and Wilmott, L., Diurnal and nocturnal tree species selection by koalas demonstrates individual preferences in a peri-urban landscape. Australian Mammalogy. https://www.publish.csiro.au/AM/justaccepted/AM23022
In New South Wales, legislation governing land clearing and development as it relates to koala conservation acts to prevent the destruction of habitat containing key tree species used by koalas. The identification of these key tree species is therefore critical to koala conservation. We aimed to compile a list of tree species used by koalas within the Wollondilly shire region and investigate tree use preferences. We radio-collared 1 female and 4 male koalas and tracked their movements over a period of 107-195 days. We conducted surveys within each koalas’ home range to quantify the relative availability of each tree species, which we compared to their relative frequency of use. Koalas used 19 different tree species (17 during day, 12 during night), despite over 32 species being available. Eight species were preferentially used by one or more koalas; these were Eucalyptuts bosistoana, E. longifolia, E. puncata, E. crebra, E. globoidea, E. pilularis, E. tereticornis and Angophora floribunda. Two species were avoided, Corymbia gummifera and Acacia decurrens. Koalas consistently used larger trees relative to their availability, and we found a general but non-significant trend towards the use of larger trees at night compared to during the day. To achieve koala conservation, it will be necessary to preserve habitat patches comprising a diverse mixture of tree species and sizes, particularly trees >35 cm DBH and appropriately revegetate land with these criteria in mind.
Shabani, F., Shafapourtehrany, M., Ahmadi, M., Kalantar, B., Özener, H., Clancy, K., Esmaeili, A., da Silva, R.S., Beaumont, L.J., Llewelyn, J. and Jones, S., 2023. Habitat in flames: How climate change will affect fire risk across koala forests. Environmental Technology & Innovation, p.103331. https://doi.org/10.1016/j.eti.2023.103331
Aim: Generate fire susceptibility maps for the present and 2070, to identify the threat wildfires pose to koalas now and under future climate change.
Time period: Present and 2070.
Major taxa studied: 60 main tree species browsed by koalas.
Method: The Decision Tree machine learning algorithm was applied to generate a fire susceptibility index (a measure of the potential for a given area or region to experience wildfires) using a dataset of conditioning factors, namely: altitude, aspect, rainfall, distance from rivers, distance from roads, forest type, geology, koala presence and future dietary sources, land use-land cover (LULC), normalized difference vegetation index (NDVI), slope, soil, temperature, and wind speed.
Results: We found a general increase in susceptibility of Australian vegetation to bushfires overall. The simulation for current conditions indicated that 39.56% of total koala habitat has a fire susceptibility rating of “very high” or “high”, increasing to 44.61% by 2070.
Main conclusions: Wildfires will increasingly impact koala populations in the future. If this iconic and vulnerable marsupial is to be protected, conservation strategies need to be adapted to deal with this threat. It is crucial to strike a balance between ensuring that koala habitats and populations are not completely destroyed by fire while also allowing for forest rejuvenation and regeneration through periodic burns.
Chen, C.J., Casteriano, A., Green, A.C. and Govendir, M., 2023. A retrospective study on antibacterial treatments for koalas infected with Chlamydia pecorum. Scientific Reports, 13(1), p.12670. https://doi.org/10.1038/s41598-023-39832-w
Chlamydiosis remains the leading infectious disease and is one of the key factors responsible for the dramatic reduction of koala populations in South-East Queensland (SEQ) and New South Wales (NSW) regions of Australia. Possible infection outcomes include blindness, infertility, painful cystitis, and death if left untreated. Studies have reported the treatment efficacy of chloramphenicol and doxycycline, which are the two most commonly administered treatments in diseased koalas, in clinical settings. However, none have directly compared the treatment efficacy of these antibacterials on koala survival. A retrospective study was essential to identify any relationships between the demographical information, and the animals’ responses to the current treatment regimens. Associations were explored between six explanatory (sex; maturity; location; clinical signs, treatment; treatment duration) and two outcome variables (survival; post-treatment PCR). Results showed that female koalas had a statistical trend of lower odds of surviving when compared to males (OR = 0.36, p = 0.05). Koalas treated with chloramphenicol for ≥ 28 days had greater odds of surviving than when treated for < 28 days (OR = 8.8, p = 0.02), and those koalas administered doxycycline had greater odds of testing PCR negative when compared to chloramphenicol treatments (OR = 5.45, p = 0.008). There was no difference between the antibacterial treatments (chloramphenicol, doxycycline, and mixed/other) and the survival of koalas. Female koalas had greater odds of exhibiting UGT signs only (OR = 4.86, p < 0.001), and also greater odds of having both ocular and UGT clinical signs (OR = 5.29, p < 0.001) when compared to males. Of the koalas, 28.5% initially had no clinical signs but were PCR positive for C. pecorum. This study enables further understanding of the complex nature between chlamydial infection and response to antibacterial treatment.
Koala Science In Brief
Hashemian, S.M.M., Madani, S.A., Allymehr, M. and Talebi, A., 2023. A molecular survey of Chlamydia spp. infection in commercial poultry and detection of Chlamydia pneumoniae in a commercial turkey flock in Iran. Veterinary Medicine and Science. https://doi.org/10.1002/vms3.1244
Casteriano, A., Van Aggelen, A.R., Fischer, S., Flanagan, C., Marschner, C., Nugent, H., Huston, W. and Higgins, D.P., 2023. Evaluation of a biosecurity survey approach for contamination by Chlamydia pecorum in koala rehabilitation, field capture, and captive settings. PeerJ, 11, p.e15842. https://doi.org/10.7717/peerj.15842
Transmission of Chlamydia pecorum between koalas is a potential risk in field capture or rehabilitation settings, where koalas are held in proximity to each other, or equipment is shared between animals. Given the impact of C. pecorum on koala welfare and population viability it is surprising that quarantine and disinfection protocols in a koala rehabilitation facility or capture settings have not previously been evaluated. This study aimed to evaluate an approach, based on the detection of chlamydial DNA and cell viability, to determine the degree of environmental contamination within a koala care facility. Various fomite sites associated with koala care at a koala rehabilitation facility in New South Wales, Australia were identified as potential sources of chlamydial contamination, following exposure to koalas known to be infected with C. pecorum. Fomite sites were swabbed following exposure, and again after decontamination procedures were carried out. Samples were tested for the presence of chlamydial DNA using qPCR and viability using both RT-qPCR and cell culture. From a total of 239 sampling events, 30 tested qPCR positive for chlamydial DNA, with 19 and 11 samples corresponding to pre-decontamination and post-decontamination events respectively. Detection of chlamydial DNA appeared to be most common in the examination room, especially on fomite sites in direct contact with koalas. Physical removal of chlamydial DNA, or its degradation by the elements, appeared to be more common on outdoor enclosures, clothing, and hands. Based on the cell culture assay, of the pre-decontamination samples with chlamydial DNA, eight had viable chlamydial cells, two of these at low levels. Of the post-decontamination samples with chlamydial DNA, one had a moderate number, and one had a very low number of viable chlamydial cells. RT-qPCR was unsuccessful in determining cell viability due to low yields of RNA and high levels of contaminants from the environmental samples. The outcomes of this study provide a knowledge base for the design of future biosecurity evaluation guidelines in captive and koala rehabilitation facilities. The higher incidence of chlamydial DNA detection by qPCR than viable organism highlights the need to use viability assays in similar studies. However, further investment is still needed to optimise these methods and improve sensitivity for complex environmental samples.
Previous Koala News & Science here: http://www.wildkoaladay.com.au/koala-news-science/july-2023/
Written by Janine Duffy President, Koala Clancy Foundation.
with support from Cheryl Egan, Organiser, Wild Koala Day.
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