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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Bangalow Koalas’ corridor on ABC Landline 27 June
A fantastic piece on massive koala tree planting in the Northern Rivers NSW.
15,000 Koala trees to be planted on Mornington Peninsula, VIC 15 June
Mornington Peninsula Koala Conservation have begun a big year of planting an estimated 15,000 koala trees around Somers & Dromana.
NSW Government asked for more detail on koala plan 23 June
The NSW Government’s proposed $200 million to double koala numbers in that state has been criticised for lack of detail.
Koala Clancy Foundation target: 300,000 koala trees by 2030 in Little, Moorabool & Barwon River systems VIC
Tree planting has begun for 2021, with 22,000 koala trees planned by mid September.
Public asked to contribute koala sightings on Kangaroo Island, SA 29 June
Passport To Recovery Project on Kangaroo Island, led by Flinders University, aims to involve community in a comprehensive wildlife census post bushfire. Citizen scientists can log sightings of koalas, sea lions and platypus on a new app.
Public meeting in Tweed to discuss plight of koalas 7 June
Cate Faehrmann MP, chair of NSW government parliamentary inquiry into koalas, visited Murwillumbah for a public meeting hosted by Tweed councillor Kate Milne and Greens candidate Dr Nola Firth. The meeting discussed threats to koalas in the region.
More koala sightings in Blue Mountains NSW 16 June
Koala trees have been planted at Springwood by Project Plant It, an initiative of Blue Mountains Youth Council. Science For Wildlife says koala sightings have been increasing at Springwood.
French Beauty Company supports koalas 4 June
In 2020, L’Occitane donated $228,000 to Foundation for National Parks & Wildlife, and has made further donations to support the new koala tree nursery setup by the Friends Of The Koala in Lismore NSW in 2021.
Byron Shire Council rejected development on koala habitat, but developer takes it to appeal. 23 June
The Land & Environment Court is hearing the case, and Commissioner has asked for more information. The ruling is likely to depend on whether the land is considered core koala habitat.
Facial recognition of koalas trialled in SE Queensland 9 June
Cameras installed at road crossing points are being trained to recognise individual koalas, using ears, nose patterns and bottom spots, in a pilot program by Griffith University.
Weed removal and tree planting for koalas at Bonville Creek, NSW 12 June
Evite Environmental Services and local landholders are working together to restore riparian areas on private land near Coffs Harbour. Invasive weeds are removed and replaced by native plants, including primary koala browse trees.
LATEST KOALA SCIENCE
Marsh, K.J., Blyton, M.D.J., Foley, W.J., and Moore, B.D., 2021. Fundamental dietary specialisation explains differential use of resources within a koala population. [online] Oecologia. Available at: <https://link.springer.com/article/10.1007/s00442-021-04962-3>
The diets of individual animals within populations can differ, but few studies determine whether this is due to fundamental differences in preferences or capacities to eat specific foods, or to external influences such as dominance hierarchies or spatial variation in food availability. The distinction is important because different drivers of dietary specialisation are likely to have different impacts on the way in which animal populations respond to, for example, habitat modification. We used a captive feeding study to investigate the mechanisms driving individual dietary specialisation in a population of wild koalas (Phascolarctos cinereus) in which individuals predominantly ate either Eucalyptus viminalis or Eucalyptus obliqua foliage. All six koalas that primarily ate E. viminalis in the wild avoided eating E. obliqua for more than 1 month in captivity. In contrast, all seven koalas that primarily ate E. obliqua could be maintained exclusively on this species in captivity, although they ate less from individual trees with higher foliar concentrations of unsubstituted B-ring flavanones (UBFs). Our results show that fundamental differences between individual animals allow some to exploit food resources that are less suitable for others. This could reduce competition for food, increase habitat carrying capacity, and is also likely to buffer the population against extinction in the face of habitat modification. The occurrence of fundamental individual specialisation within animal populations could also affect the perceived conservation value of different habitats, translocation or reintroduction success, and population dynamics. It should therefore be further investigated in other mammalian herbivore species.
Santamaria, F., Barlow, C.K., Schlagloth, R., Schittenhelm, R.B., Palme, R., and Henning, J., 2021. Identification of Koala (Phascolarctos cinereus) Faecal Cortisol Metabolites Using Liquid Chromatography-Mass Spectrometry and Enzyme Immunoassays. [online] MDPI. Available at: <https://www.mdpi.com/2218-1989/11/6/393> https://www.mdpi.com/2218-1989/11/6/393
The koala (Phascolarctos cinereus) is an arboreal folivorous marsupial endemic to Australia. Anthropogenic activities and climate change are threats to this species’ survival and are potential stressors. A suitable non-invasive method is needed to objectively detect stress in koalas. Under conditions of stress, the concentration of the hormone cortisol in plasma or in saliva is elevated, and this would provide a convenient measure; however, collecting blood or saliva from wild animals is both practically difficult and stressful, and so likely to confound any measurement. In contrast, measurement of cortisol metabolites in faeces provides a practical and non-invasive method to objectively measure stress in koalas. Unfortunately, the identity of the main faecal cortisol metabolites of koalas is unknown. In this study, we have used both untargeted liquid chromatography–mass spectrometry (LC-MS) and enzyme immunoassays (EIAs) to identify several faecal cortisol metabolites in two koalas, one female (18 months old, 4.1 kg) and one male (4 years old, 6.95 kg) upon administration of hydrocortisone (cortisol) sodium succinate. The LC-MS analysis identified tetrahydrocortisol along with several other isomers as cortisol metabolites. After a survey of five enzyme immunoassays, we found that two metabolites, tetrahydrocortisol and 3β-allotetrahydrocortisol, could be detected by EIAs that used antibodies that were raised against their structurally similar corticosterone counterparts, tetrahydrocorticosterone and 3β-allotetrahydrocorticosterone, respectively. While the 3β-allotetrahydrocortisol metabolite was detected in the faeces of only one of the two animals studied, tetrahydrocortisol was detected in both. These results ultimately indicate that tetrahydrocortisol is likely the main faecal cortisol metabolite in koalas, and we demonstrate that it can be measured by an EIA (50c) that was originally developed to measure tetrahydrocorticosterone.
Dissanayake, R.B., Stevenson, M., Allavena, R., and Henning, J., 2021. Predicting koala (Phascolarctos cinereus) distribution from incidental sighting data in South-East Queensland, Australia. Global Ecology and Conservation, 28. https://www.sciencedirect.com/science/article/pii/S2351989421002122
Species distribution maps are important tools for wildlife conservation planning and management. To model koala distributions, usually, a spatially representative sample of koala populations is collected through systematic field surveys. Details of koala sightings collected by members of the public could potentially be used to develop species distribution models if appropriate analytical approaches are applied to address the inherent biases in such datasets. We developed a stepwise approach for applying bias correction techniques to estimate and map koala distributions. Using a Boosted regression tree approach, we modelled indirectly the search effort made by observers to identify or sight koalas. Land lot density (58%) and human population density (19%) had the strongest positive impact on the indirect search effort, while the distances to roads were negatively associated with the indirect search effort. To estimate the koala distribution across South-East Queensland, we then developed models describing koala habitat (environmental model), access to koala habitat (accessibility model) and the search effort (search effort model), with the latter including the indirect search effort covariate. Finally, we corrected the estimates derived from these models (bias-corrected search effort and accessibility model). Three independent statistical modelling approaches (Lasso penalty Poisson regression, Down-weighted Poisson regression, and Maximum entropy) were used to compare the five koala distribution models. Based on assessments of areas under curves, the predictive accuracy of models improved when area accessibility and search effort were included. Overall, the spatial extent of koala distributions increased in the prediction maps when models were corrected for accessibility and indirect search effort (except for Down-weighted Poisson regression).
Other papers of interest
Golumbic, Y. N., Baram-Tsabari, A. and Fishbain, B. (2020). ‘Engagement styles in an environmental citizen science project’. JCOM 19 (06), A03. https://doi.org/10.22323/2.19060203. https://jcom.sissa.it/archive/19/06/JCOM_1906_2020_A03
This paper identifies the diverse ways in which participants engage with science, through the same citizen science project. Using multiple data sources, we describe various activities conducted by citizen scientists in an air quality project, and characterize the motivations driving their engagement. Findings reveal several themes, indicative of participants motivations and engagement; worried residents, education and outreach, environmental action, personal interest and opportunistic engagement. The study further illustrates the interconnectivity between science communication and citizen science practices and calls for nurturing this relationship for the mutual advancement of both fields.
Wedrowicz, F., Mosse, J., Wright, W. et al. Genetic structure and diversity of the koala population in South Gippsland, Victoria: a remnant population of high conservation significance. Conserv Genet 19, 713–728 (2018). https://doi.org/10.1007/s10592-018-1049-8 https://link.springer.com/article/10.1007/s10592-018-1049-8#Abs1
In the Australian state of Victoria, the history of koalas and their management has resulted in the homogenisation and reduction of genetic diversity in many contemporary populations. Decreased genetic diversity may reduce a species’ ability to adapt to future environmental pressures such as climate change or disease. The South Gippsland koala population is considered to be unique in Victoria, as it is believed to be a remnant population, not originating from managed populations that have low genetic variation. This study investigated genetic structure and diversity of koalas in South Gippsland, with comparison to other populations in Victoria (French Island/Cape Otway, FI and Raymond Island, RI), New South Wales and south east Queensland. Population analyses were undertaken using both microsatellite genotype and mitochondrial DNA sequence data. Non-invasive sampling of koala scats was used to source koala DNA, allowing 222 South Gippsland koalas to be genotyped. Using nuclear data the South Gippsland koala population was found to be significantly differentiated (Djost 95% CI SG–RI = 0.03–0.06 and SG–FI = 0.08–012) and more diverse (AR 95% CI SG = 4.7–5.6, RI = 3.1–3.3, FI = 3.0–3.3; p = 0.001) than other Victorian koala populations, supporting the premise that koalas in the South Gippsland region are part of a remnant population, not derived from translocated island stock. These results were also supported by mitochondrial data where eight haplotypes (Pc4, Pc17, Pc26, Pc27, and Pc56–Pc59) were identified in South Gippsland while a single haplotype (Pc27) was found in all island koalas tested. Compared to other Victorian koala populations, greater genetic diversity found in South Gippsland koalas, may provide this population with a greater chance of survival in the face of future environmental pressures. The South Gippsland koala population is, therefore, of high conservation significance, warranting the implementation of strategies to conserve this population and its diversity into the future.
Previous Koala News & Science here: http://www.wildkoaladay.com.au/koala-news-science/koala-news-science-may-2021/
Written by Janine Duffy President, Koala Clancy Foundation
with support from Cheryl Egan, Organiser, Wild Koala Day
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