Effective conservation strategies rely on knowledge of seasonal and social drivers of animal behaviour. Koalas are generally solitary and their social arrangement appears to rely on vocal and chemical signalling. Male koala vocalisations, known as bellows, are believed to be closely related to their breeding behaviour. Previous research suggests that oestrous female koalas use bellows to locate unique males to mate with, and that males can similarly use bellows to evaluate the physical attributes of their peers. We tested the behavioural responses of 20 free ranging koalas to bellow recordings collected from small (<6 kg) and large (>8.5 kg) adult male koalas. Individual koala movement was reported by hourly-uploaded GPS coordinates. We report evidence of intra-male competition, with adult males approaching bellow playbacks, particularly those from small-sized males. In contrast, males under three years of age were averse to the playbacks. No patterns in the response of females were detected. Our results provide the strongest evidence yet that bellows are primarily a means by which males occupy and control space during the breeding season. Future studies are required to see if female response to bellows depends on their reproductive status.

We evaluated long range antennae and associated solar-powered global positioning system (GPS) ear tags designed for use with domestic cattle, as a novel system for monitoring ranging behaviour of the koala (Phascolarctos cinereus). The mean location error of our GPS tags was 33.9 m (s.e. = 0.46). The tags were relatively light (30 g), reported eight locations per day when attached to koala radio-collars and had an operating life that exceeded our study period (8 months). Deployed as a stand-alone, solar powered, remote system, this technology can provide a viable option for wildlife tracking projects.

The koala population in northern Australia has become increasingly fragmented due to natural and man-made barriers and interventions. This situation has created a unique opportunity to study both endogenous and exogenous koala retrovirus (KoRV). To determine the impact that population isolation has had on KoRV diversity in Queensland, 272 koalas from six fragmented koala populations were profiled for their KoRV provirus across two natural biogeographical barriers (the St Lawrence Gap and the Brisbane Valley Barrier), one man-made geographical barrier (the city of Brisbane) and two translocation events (the single movement of koalas to an island and the repeated movement of koalas into a koala sanctuary). Analysis revealed that all koalas tested were KoRV-A positive, with 90 - 96% of the detected KoRV provirus from each koala representing a single, likely endogenous, KoRV-A strain. The next most abundant proviral sequence was a defective variant of the dominant KoRV-A strain, accounting for 3 - 10% of detected provirus. The remaining KoRV provirus represented expected exogenous strains of KoRV and included geographically localized patterns of KoRV-B, -C, -D, -F, -G, and -I. These results indicate that lineage diversification of exogenous KoRV is actively ongoing. In addition, comparison of KoRV provirus within known dam-sire-joey family groups from the koala sanctuary revealed that joeys consistently had KoRV proviral patterns more similar to their dams than their sires in KoRV-B, -C and -D provirus composition. Collectively, this study highlights both the consistency of endogenous KoRV and the diversity of exogenous KoRV across the fragmented koala populations in northern Australia.IMPORTANCE KoRV infection has become a permanent part of koalas in northern Australia. With KoRV presence and abundance linked to more severe chlamydial disease and neoplasia in these koalas, understanding how KoRV exists throughout an increasingly fragmented koala population is a key first step in designing conservation and management strategies. This survey of KoRV provirus in Queensland koalas indicates that endogenous KoRV provirus is ubiquitous and consistent throughout the state while exogenous KoRV provirus is diverse and distinct in fragmented koala populations. Understanding the prevalence and impact of both endogenous and exogenous KoRV will be needed to ensure a future for all koala populations.

Habitat loss and fragmentation threaten the survival of koalas in Queensland. In rural landscapes, remaining koala habitat is often in the form of scattered paddock trees, patches of vegetation and roadside vegetation. The aims of this study were to (1) quantify the use of these three habitat types; (2) determine whether there is an increased use of scattered trees during the breeding season; and (3) describe the movement characteristics (daily step-length and turning angle) of koalas in different habitat types. To do this, koalas were caught and fitted with global positioning system (GPS) loggers that recorded their daily locations. We found koalas utilised all three habitat types in both breeding and non-breeding seasons, but roadside vegetation and scattered trees were utilised significantly more than expected based on their availability within the landscape. We found no significant difference in step-length or turning angles in scattered trees compared with patches of vegetation. We conclude that scattered trees are a critical element of habitat in this rural landscape. This work provides evidence that retaining or planting scattered trees within the rural landscape would likely complement or possibly enhance the conservation value of rural landscapes for koalas.

Declining population sizes of koalas (Phascolarctos cinereus) in SE Queensland (QLD), Australia can partially be attributed to chlamydiosis, with the majority of epidemiological studies focusing on the prevalence of infection and associated pathology in female koalas, with lesser attention given to males. We aimed to explore the epidemiology of Chlamydia pecorum infection in the male urogenital tract from wild (hospitalized and free-ranging) koalas in SE QLD. Although 67% of male koalas were infected with C. pecorum in their urogenital tract and 55% were shedding the organism in their semen, only a third of the males sampled presented with overt signs of urogenital disease. Infection with C. pecorum was lower in populations from rural locations, compared with periurban locations, with a corresponding low association between urogenital infection and clinical disease. The presence of C. pecorum in penile urethral swabs was a good predictor of the presence of C. pecorum in semen, with a significant correlation (P=0.006) in 58% of males. In contrast, the C. pecorum load in penile urethral swabs was not a good predictor of the C. pecorum load in semen, with no significant correlation. In addition, 57% of male koalas had large numbers of bacterial copy numbers in the penile urethra (upper quartile) and 40% shedding into semen with no overt signs of disease. Investigation of the association of C. pecorum infection, body condition score, and age revealed that the highest incidence of urogenital infection occurred in males with the lowest body score (1 out of 10). Furthermore, 63% of sexually mature male koalas (>2 yr old) had urethral infections and 50% had C. pecorum in their semen. Our study suggested that the role of chlamydia in male koala infertility has been previously underestimated.

Infectious diseases have contributed to the decline in the health of koala (Phascolarctos cinereus) populations in the wild in some regions of Australia. Herein we report the development and validation of 2 multiplex real-time PCR (rtPCR) panels for the simultaneous detection of Mycoplasma spp., Ureaplasma spp., Bordetella bronchiseptica, and Chlamydia, including speciation and quantification of Chlamydia, in ocular, reproductive, and nasal swab samples in addition to semen and male urogenital and reproductive tissues, from koalas. Each rtPCR panel was developed for use as a single-tube reaction using pathogen-specific primers and fluorescently labeled probe sets. DNA extracted from reference strains and isolates was used for validation of sequence gene targets for the multiplex rtPCR panels. Each panel was shown to be sensitive and specific in detecting and differentiating the bacterial pathogens. The multiplex rtPCR panels were used to screen clinical samples from free-ranging and hospitalized koalas for multiple pathogens simultaneously. The multiplex rtPCR will improve turnaround time compared to individual-pathogen rtPCR methods used, to date, for confirmation of diagnosis and will provide the wildlife clinician with the ability to make treatment decisions more rapidly.

Determining the role of an infectious agent in contributing to wildlife population declines is a pervasive problem in the field of conservation biology. We expand on a recently proposed broad investigative approach for disease, with a systematic framework outlining the specific types of individual- and population-scale empirical evidence required to demonstrate whether a pathogen is a component cause of declines in wild animal populations. Using koala (Phascolarctos cinereus) population declines and their putative association with the bacterial disease chlamydiosis (Family Chlamydiaceae) as a case study, we review the relevant published literature and synthesize a logical conceptual argument based on our suggested framework. Available empirical evidence supports a role for chlamydiosis contributing to host mortality and sterility, and cannot rule out a role of chlamydiosis as a component cause of koala population declines. However, the relative importance of chlamydiosis (among other threatening processes) as a driver of changes in koala demography and autecology may differ depending on the particular population or system examined, and this has yet to be elucidated over the koala's distributional range. Our approach allows us to highlight current research gaps in order to assist with future policy planning and conservation strategy. We recommend that a similar approach will assist in the evaluation of the role of disease in population declines in other ecological systems.

The Australian koala is an iconic marsupial with highly specific dietary requirements distributed across heterogeneous environments, over a large geographic range. The distribution and genetic structure of koala populations has been heavily influenced by human actions, specifically habitat modification, hunting and translocation of koalas. There is currently limited information on population diversity and gene flow at a species-wide scale, or with consideration to the potential impacts of local adaptation. Using species-wide sampling across heterogeneous environments, and high-density genome-wide markers (SNPs and PAVs), we show that most koala populations display levels of diversity comparable to other outbred species, except for those populations impacted by population reductions. Genetic clustering analysis and phylogenetic reconstruction reveals a lack of support for current taxonomic classification of three koala subspecies, with only a single evolutionary significant unit supported. Furthermore, ~70% of genetic variance is accounted for at the individual level. The Sydney Basin region is highlighted as a unique reservoir of genetic diversity, having higher diversity levels (i.e., Blue Mountains region; AvHecorr=0.20, PL% = 68.6). Broad-scale population differentiation is primarily driven by an isolation by distance genetic structure model (49% of genetic variance), with clinal local adaptation corresponding to habitat bioregions. Signatures of selection were detected between bioregions, with no single region returning evidence of strong selection. The results of this study show that although the koala is widely considered to be a dietary-specialist species, this apparent specialisation has not limited the koala's ability to maintain gene flow and adapt across divergent environments as long as the required food source is available.

Infectious diseases can be key threatening processes for biodiversity conservation. However, establishing the relative importance of disease (among other threatening processes) as a driver of species declines can be challenging. Bias in the directions that a research field may take as it develops – due to factors such as conservation policy, funding, public perception, and available expertise and technology – may exacerbate this difficulty. Chlamydiosis (infection with bacteria in Family Chlamydiaceae) is an example of an infectious disease with a poorly understood role in koala (Phascolarctos cinereus) population dynamics. The arboreal folivorous koala is an internationally recognized iconic species of high conservation, sociocultural and economic value. To date, no studies have quantitatively examined the breadth and scope of research related to koala chlamydiosis, nor systematically identified the current research gaps. We systematically and quantitatively reviewed a comprehensive database of literature related to koala chlamydiosis, classified and examined the main foci of the research, and evaluated research gaps with the goal of assisting policy planning for funding further koala chlamydiosis research. We examined published literature with regard to journal category, authorship, funding, spatiotemporal scope, study foci and type, chlamydial species examined, methodological design and overall findings. Among the 117 peer-reviewed papers published between 1970 and 2016 that fit our criteria, the most striking finding was the relative lack of population-level disease studies within the last two decades to examine mechanisms of chlamydial infection dynamics. This research gap is of particular concern given the potential role of Chlamydia in koala population declines, and the recent dramatic changes in our understanding of pathogen phylogeny and improved diagnostic approaches. Our results demonstrate a pressing need for future in situ comprehensive longitudinal population-level studies from diverse geographic regions. These studies must utilize up-to-date diagnostic methods capable of distinguishing chlamydial species and strains to elucidate the role of chlamydial infection in koala population declines and the underlying mechanisms involved. They should also employ rigorous epidemiological methodologies and evaluate co-infection, habitat, climatic and demographic data. Our findings suggest some key research gaps concerning koala chlamydiosis, and are hence important for guiding future research into koala chlamydiosis and conservation.

It can be difficult to establish the conservation significance of endemic infectious diseases—those that are well established in a population—in contrast with infectious diseases that are still invading. This difficulty can have important implications for designing policy to address species declines. The infectious diseases of koalas provide an ideal case study to examine issues involved in identifying the role of endemic disease in conservation biology. Koala populations are in decline, amidst claims for many years that infectious diseases, particularly those with chlamydial etiology, play a key role in this loss. However, weak associations between prevalence of infection, clinical signs of disease, and population decline mean that it remains unclear whether infectious disease is a primary driver of koala population decline. There are multiple causes of koala decline including drought, habitat destruction, and disease. Well‐designed experiments, linked to appropriate models, are necessary to determine the true role of infectious disease in the current koala population declines and whether a focus on disease is likely to be a feasible, let alone the most cost‐effective, means of preventing further declines.

It is imperative that the reported results of scientific studies are based on sound data analyses and unbiased interpretation, especially where they may be used to guide government policy and regulation. A recent paper by Phillips (2016) evaluated the behavioural response of radio-collared koalas to an inaugural large music festival held in 2010 in northern New South Wales. The study concluded that six of seven koalas showed an aversive response. However, we regard the paper as misleading because it contains serious errors in the examination of koala home ranges and in the subsequent assessment of ‘aversive behaviour’ during the music festival. We conclude that Phillips’ paper is based on sufficient data to state that three, not six, of the koalas he studied displayed a short-term behavioural response to the music festival. These koalas temporarily moved outside of their estimated ranges during the festival period (10–80 m). Further, Phillips fails to report crucial ecological data regarding the high level of disease and mortality he recorded, which are presented in their entirety in the author’s prior, unpublished report. For the two deaths that are reported, no mention is made that these koalas had pre-existing disease. Rather, the author raises the possibility that the mortalities may have been related to festival-induced stress. The omission of such key data is prejudicial to the interpretation of results. The reported short-term impact of the festival upon some of the study animals is indeed noteworthy; however, it is apparent that the impact has been considerably overstated due to errors of analysis and the omission of critical ecological data. Our critique highlights our concerns by drawing on the author’s unpublished report as well as our own research at the same site over the past five years. Our aim is to ensure that debate over the impact of music festivals on wildlife is based on sound data analyses and unbiased interpretation, to provide guidance to relevant regulators and land managers.

Daylight saving time (DST) could reduce collisions with wildlife by changing the timing of commuter traffic relative to the behaviour of nocturnal animals. To test this idea, we tracked wild koalas ( Phascolarctos cinereus ) in southeast Queensland, where koalas have declined by 80% in the last 20 years, and compared their movements with traffic patterns along roads where they are often killed. Using a simple model, we found that DST could decrease collisions with koalas by 8% on weekdays and 11% at weekends, simply by shifting the timing of traffic relative to darkness. Wildlife conservation and road safety should become part of the debate on DST.

The koala (Phascolarctos cinereus) is an iconic Australian species that is currently undergoing a number of threatening processes, including disease and habitat loss. A thorough understanding of population genetic structuring and genomic variability of this species is essential to effectively manage populations across the species range. Using a reduced representation genome sequencing method known as double digest restriction-associated sequencing, this study has provided the first genome-wide SNP marker panel in the koala. In this study, 33,019 loci were identified in the koala and a filtered panel of 3060 high-utility SNP markers, including 95 sex-linked markers, were used to provide key insights into population variability and genomic variation in 171 koalas from eight populations across their geographic range. Broad-scale genetic differentiation between geographically separated populations (including sub-species) was assessed and revealed significant differentiation between all populations (FST range = 0.01–0.28), with the largest divergence observed between the three geographically distant subgroups (QLD, NSW and VIC) along the east coast of Australia (average FST range = 0.17–0.23). Sub-group divergence appears to be a reflection of an isolation by distance effect and sampling strategy rather than true evidence of sub-speciation. This is further supported by low proportions of AMOVA variation between sub-species groups (11.19 %). Fine-scale analysis using genome-wide SNP loci and the NETVIEW pipeline revealed cryptic genetic sub-structuring within localised geographic regions, which corresponded to the hierarchical mating system of the species. High levels of genome-wide SNP heterozygosity were observed amongst all populations (He = 0.25–0.35), and when evaluating across the species to other vertebrate taxa were amongst the highest values observed. This illustrates that the species as a whole still retains high levels of diversity which is comparable to other outbred vertebrate taxa for genome-wide SNPs. Insights into the potential for adaptive variation in the koala were also gained using outlier analysis of genome-wide SNPs. A total of 10 putative outlier SNPs were identified indicating the high likelihood of local adaptations within populations and regions. This is the first use of genome-wide markers to assess population differentiation at a broad-scale in the koala and the first time that sex-linked SNPs have been identified in this species. The application of this novel genomic resource to populations across the species range will provide in-depth information allowing informed conservation priorities and management plans for in situ koalas across Australia and ex situ around the world.

The great outdoors is the laboratory for most studies in ecology. This article reports on the use of cameras, competition and creativity as novel ways to assess learning during a one-day field trip for a large (~600 students) introductory biology/ecology course. Among the assessment activities, students find and photograph examples of various types of ecological interactions, create a dichotomous plant key in the lab and apply it in the field, and evaluate the potential impact of various environmental change scenarios on ecosystems. The activities and accompanying assessment foster higher order thinking (such as application, evaluation and synthesis) and better retention of knowledge because students create their own context for concepts and content, which have traditionally been learned by rote approaches. This article provides practical advice on how to implement this type of assessment.

The koala (Phascolarctos cinereus), one of the world's most iconic faunal species, was recently listed under Australian government legislation as vulnerable in the northern states of Queensland and New South Wales and in the Australian Capital Territory, but not in the southern states of Victoria and South Australia. This review synthesises empirical evidence of regional koala population trends, their conservation outlook, and associated policy challenges. Population declines are common in the northern half of the koala's range, where habitat loss, hotter droughts, disease, dog attacks and vehicle collisions are the major threats. In contrast, some southern populations are locally overabundant and are now subject to managed declines. The koala presents the problem of managing a wide-ranging species that now primarily occurs in human-modified landscapes, some of which are rapidly urbanising or subject to large-scale agricultural and mining developments. Climate change is a major threat to both northern and southern populations. The implementation of policy to conserve remaining koala habitat and restore degraded habitat is critical to the success of koala conservation strategies, but habitat conservation alone will not resolve the issues of koala conservation. There needs to be concerted effort to reduce the incidence of dog attack and road-related mortality, disease prevalence and severity, and take into account new threats of climate change and mining. Many of the complex conservation and policy challenges identified here have broader significance for other species whose population trends, and the nature of the threatening processes, vary from region to region, and through time.

Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus--the only extant member of the family Phascolarctidae) is poorly known and much of the koala's sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas.

Context Captive breeding for release back to the wild is an important component of ex situ conservation but requires genetic diversity that is representative of the wild population and has the ultimate goal of producing ecologically sustainable and resilient populations. However, defining and testing for representativeness of captive populations is difficult. Koalas (Phascolarctos cinereus) are bred for educational and tourism purposes in zoos and wildlife parks in South-East Queensland, but there are drastic declines evident in some wild koala populations in this region. Aim We compared genetic diversity at microsatellite loci and mitochondrial DNA in two captive koala populations with that of the local, wild koalas of South-East Queensland, determining the degree to which genetic diversity of neutral loci had been preserved and was represented in the captive populations. Key results The expected heterozygosity and the allelic richness was significantly greater in one captive colony than one wild South-East Queensland population. There was low but significant differentiation of the captive from wild populations using FST, with greater differentiation described by Jost’s Dest. In contrast, a newly introduced Kullback–Leibler divergence measure, which assesses similarity of allele frequencies, showed no significant divergence of colony and wild populations. The captive koalas lacked many of the mitochondrial haplotypes identified from South-East Queensland koalas and possessed seven other haplotypes. Conclusions Captive colonies of koalas have maintained levels of overall neutral genetic diversity similar to wild populations at microsatellite loci and low but significant differentiation likely resulted from drift and founder effects in small captive colonies or declining wild populations. Mitochondrial DNA suggests that captive founders were from a wider geographic source or that haplotypes have been lost locally. Implications Overall, tested captive koalas maintain sufficient microsatellite diversity to act as an in situ reservoir for neutral genetic diversity of regional populations.

We used computer-aided image analysis of leaf fragment particles found in faecal pellets of 45 koalas, representing the range of tooth wear in this species, to investigate how tooth wear in the koala influences faecal particle sizes. Although the range of sizes of particles produced did not vary between koalas across different tooth wear classes, with all koalas producing small, medium and large particles, koalas with advanced tooth wear produced a greater proportion of larger particles. This observation may prove useful for demographic population analyses based on scat surveys since the broad age class of individual koalas can be estimated from faecal pellet analysis. Older koalas produced faecal pellets containing a higher proportion of the largest-sized particle sizes (those greater than 0.59 mm2) than either young or mature koalas but there was no difference detected between mature and young koalas.