Australian Journal of Zoology

We used GPS telemetry to investigate space use and movements of 15 grey goshawks (Tachyspiza novaehollandiae) in south-east Tasmania, Australia, between 2021 and 2023. The number of nests per territory in 73 active breeding territories was also determined and inter-nest distances were calculated. Mean minimum convex polygon (MCP) non-breeding season home range size of female goshawks was more than twice as large as the mean breeding season home range size. Home range size of males was similar in the breeding and non-breeding seasons and the MCP estimates suggest their home ranges are much larger than that of females. Tracked goshawks were range residents throughout the year with kernel density (KD) core areas centred on nest trees and preferred foraging locations. Movement patterns were highly recursive although some individuals occasionally undertook long range excursions away from their nests. Mean number of nests per goshawk breeding territory was 2.0 (range 1–6). Median distance between nests in breeding territories was 78.0 m (range 1.8–915.0 m). We recommend that prescriptive nest reserves for grey goshawks be implemented based on our 50%, 75% and 95% KD core area estimates for females in the breeding season. We provide a conceptualised example of a nest reserve design.

The capacity for dispersal is an important determinant of a species’ resilience to decline from the serial extinction of local populations. Dispersal of animals can be difficult to measure directly but population genetics provides a powerful tool for identifying dispersal limits. This study used microsatellite markers to investigate population structuring of the white-fronted chat (Epthianura albifrons) across its geographic range. Because the species is threatened in the north-eastern part of its range, the primary aim was to identify barriers limiting dispersal. Isolation by distance was not apparent across the 3000 km mainland range but populations on three oceanic islands, and two mainland sites surrounded by urbanisation, were genetically distinct from each other and the other mainland sites. The small populations that were surrounded by urbanised land had significantly lower genetic diversity (allelic diversity and heterozygosity) than the other mainland populations, with the oceanic island populations showing intermediate levels of diversity. These results suggest that although being a partially nomadic species, which facilitates its dispersal over continuous habitat, the species does not have the flight capacity of some other small passerines and is sensitive to habitat discontinuity. Populations inhabiting small areas of coastal saltmarsh in areas with large human populations are likely to face increasing threat levels.

Rocky landforms offer a complex and persistent habitat for a diverse range of fauna. The Mount Isa Inlier bioregion of north-west Queensland is dominated by such landforms, but the faunal assemblage inhabiting them has received scant attention. We conducted a 13-month camera trap study at 60 camera stations, totalling 21,965 camera days, aimed at detecting the faunal assemblage present on these landforms. We categorised each identified taxon as either a rocky landform specialist or non-specialist. We identified 15 specialists and implemented a multiseason community occupancy model for 12 of these to assess how they utilised rocky landforms over the course of a year, and according to a suite of environmental characteristics. Rates of use of rocky landforms increased in November and decreased in April. At the community level we found higher rates of use of south and west slopes than north slopes, higher rates of use of rocky hills than jumpups, and higher rates of use of metamorphic and igneous geologies than sedimentary ones. We provide the first evidence of this unique community’s use of the landscape through both space and time and highlight broad site characteristics of candidate areas in which to focus future management and conservation initiatives.

Telemetry neck collars are commonly used to collect spatial data on free ranging animals. Two major challenges in application are entanglement prevention and retrieval of the collars after the study. Weak links made of a degradable material that breaks down while deployed on the animal are a potential solution to reduce entanglement and prevent the need to capture or sedate animals for retrieval. However, weak links can perform inconsistently depending on an animal’s behaviour and environmental factors such as heat and humidity. A study of disease in eastern grey kangaroos (Macropus giganteus) in Victoria, Australia, provided an opportunity to test the performance of 35 radio collars fitted with a latex weak link between May and July 2022. At the conclusion of the study, 20 collars were manually removed from euthanised animals, and 15 detached in the field; all of these broke at the weak link. Of the 15 detached collars, 10 dropped from live animals due to degradation between 106 and 208 days (mean = 147 days) after deployment, four kangaroos were found dead and their collars were retrieved nearby and one dropped immediately after attachment. The performance of the device in this study demonstrates the utility of weak links as a cheap and simple remote detachment tool to prevent entanglement and achieve remote detachment of neck collars during animal tracking studies.

The new Editors-in-Chief for the Journal discuss changes to the editorial team, along with their future plans for broadening the Journal’s scope and encouraging submissions across the different article types currently offered by AJZ.

The fluctuating environment of arid lands drives spatial and temporal variation in resource availability and habitat suitability for animals. Patches of vegetative growth may create refuges that allow populations to persist when resources are scarce. Yet the links between fine-scale spatial variation and animal abundance are not well known. Here, we examine whether spatial variation in habitat and microhabitat create spatial mosaics in animal abundance. We surveyed ground-dwelling vertebrates and invertebrates in two adjacent habitats in semiarid Australia (cracking clay floodplains and rocky gibber), and across variation in microhabitat (vegetation cover). There was considerable variation in vegetation cover, creating fine-scale spatial mosaics of microhabitats. However, animal community composition did not vary significantly across the two main habitats. At the microhabitat level, numbers of spiders and reptiles were positively associated with woody vegetation cover. Vegetation cover did not significantly impact other taxonomic groups or overall community composition. The results show that response to microhabitats by animal populations is taxon-specific. Woody shrubs may provide a more reliable or more detectable microhabitat refuge compared to grasses for particular taxa. Informed wildlife conservation in arid lands requires investigating taxon-specific habitat and microhabitat associations, as well as the scale and persistence of these associations.

Humpback whales (Megaptera novaeangliae) migrate from their Antarctic feeding grounds to their north-west Australian breeding grounds. North-west Australia has experienced rapid development of the mining and petroleum industry, and remains under increasing human pressure. The aim of this study was to examine the spatiotemporal distribution of humpback whales across the north-west: North West Cape, Pilbara and Exmouth Gulf. Aerial surveys (n = 184) were conducted from 2000 to 2010. After accounting for survey effort, kernel density estimation was used to assess the monthly distribution of whales. The largest density hotspot of whale groups was the centre to western edge of Exmouth Gulf. The highest encounter rate of mother–calf pairs was in October in Exmouth Gulf (0.0447 ± 0.0082 groups/km), which was significantly higher than in the North West Cape and Pilbara (0.0005 ± 0.0002 and 0.0011 ± 0.0005 groups/km, respectively). The comparison among the three regions confirms and quantifies Exmouth Gulf as an important nursery area for humpback whale mother–calf pairs. Nursery areas are important for lactating humpback whale mothers as they carry the highest energetic demands in the population. It is crucial that nursery areas remain relatively undisturbed from human pressures so mothers can rest to conserve energy and nurse their young.

White flash camera-traps are avoided in predator monitoring as they are assumed to lower redetection, despite infrared cameras producing lower-quality night images thus limiting the scope for individual identification and, consequently, the accuracy of density estimates. We sought to determine whether flash type impacts the behaviour of cats (Felis catus). We identified different behavioural responses exhibited by photographed cats, and quantitatively assessed relative activity, redetection rates, and the activity of specific individuals using 11,389 images of feral cats from 62 white flash and 62 infrared camera-traps across Tasmania. We found no difference in the relative activity of cats between flash types (odds ratio of 0.90, [null expectation = 1], CI = 0.55, 1.47), and there was no evidence of a reduction in redetection rate of feral cats following initial detection (odds ratio = 0.83, CI = 0.47, 1.46). The activity of individuals was similar between white flash (average = 0.026, CI = 0.021, 0.032), and infrared cameras (average = 0.028, CI = 0.022, 0.035). White flash cameras appear suitable for monitoring feral cats without resulting in a negative bias, highlighting the need for researchers to critically examine assumptions regarding best methodology.

Hybridisation between Australian dingoes and domestic dogs is a controversial area of interest and research. An ongoing canine sterilisation programme in rural and remote Western Australia provided an opportunity to assess the dingo ancestry of camp dogs and opportunities for hybridisation. Blood samples were collected from 345 individual community dogs at 21 locations. Dogs were screened using 23 microsatellite loci and ancestry percentage assigned using an iterative Bayesian assignment algorithm. A single individual was a dingo, 96% were domestic dogs and 3.5% were hybrids. Camp dog and dingo hybridisation in these areas is of little concern in terms of conserving dingo purity.

Despite painted button-quail, Turnix varius, being one of Australia’s most common and widespread button-quail, knowledge of the species’ habitat use and movements is poor, and largely based on incidental observations. We GPS tracked eight painted button-quail individuals near Mareeba in northern Queensland during both dry (May to June 2020) and wet (January to February 2021) seasons. We found no evidence of nomadic or migratory movements; individuals occupied small home ranges (1.38–10.3 ha) and the species was present year-round. Differences in home-range size were detected between sexes and between seasons, likely reflecting the species’ polyandrous mating system. In both wet and dry seasons, painted button-quail occupied open savanna with a groundcover of native perennial tussock grasses. The home ranges of all tracked birds were associated mostly with ridges and slopes, although some use of alluvial flats was observed. The presence of perennial tussock grasses was consistent across the areas used by tracked individuals. In contrast to anecdotal reports, painted button-quail utilised areas with open groundcover (as low as 5% groundcover vegetation) as well as areas of dense cover (95% groundcover vegetation). Given that this is the first GPS-based movement study of any button-quail species, our findings provide potentially important insights into the daily and annual movements of this cryptic genus.

Pedipalps – chelate ‘pincers’ as the second pair of prosomal appendages – are a striking feature of scorpions and are employed in varied biological functions. Despite the distinctive morphology and ecological importance of these appendages, their anatomy remains underexplored. To rectify this, we examined the pedipalps of the Australian black rock scorpion, Urodacus manicatus, using a multifaceted approach consisting of microcomputed tomography, scanning electron microscopy, energy dispersive X-ray spectroscopy, and live pinch force measurements. In doing so, we document the following aspects of the pedipalps: (1) the musculature in three dimensions; (2) the cuticular microstructure, focusing on the chelae (tibial and tarsal podomeres); (3) the elemental construction of the chelae teeth; and (4) the chelae pinch force. We recognise 25 muscle groups in U. manicatus pedipalps, substantially more than previously documented in scorpions. The cuticular microstructure – endo-, meso-, and exocuticle – of U. manicatus pedipalps is shown to be similar to other scorpions and that mesocuticle reinforces the chelae for predation and burrowing. Elemental mapping of the chelae teeth highlights enrichment in calcium, chlorine, nickel, phosphorus, potassium, sodium, vanadium, and zinc, with a marked lack of carbon. These elements reinforce the teeth, increasing robustness to better enable prey capture and incapacitation. Finally, the pinch force data demonstrate that U. manicatus can exert high pinch forces (4.1 N), further highlighting the application of chelae in subduing prey, as opposed to holding prey for envenomation. We demonstrate that U. manicatus has an array of adaptions for functioning as a sit-and-wait predator that primarily uses highly reinforced chelae to process prey.

In the face of global biodiversity declines, conservation measures are urgently needed. However, our lack of knowledge on species’ diversity, distributions and population trends presents a major obstacle, particularly for morphologically cryptic species. Field surveys to gather this information present a logistical challenge, but the rapid rise of citizen science presents a new opportunity, generating huge volumes of data rapidly across a species’ range. We use data from a national citizen-science project to document the distribution and advertisement call variability in a group of five morphologically conserved treefrogs. Using 542 male advertisement calls across the entire range of five species, we found considerable levels of acoustic variation both among and within species. Note shape, notes per call and positions of the longest and shortest notes were most useful to delineate species. Our research will assist in species delineation and identification in the field and form the basis for a more accurate understanding of species diversity and distributions in the brown tree frog complex. We also demonstrated the utility of citizen science in documenting species distributions and diversity.

Large (>3 m) slender-bodied rat snakes are abundant in agroecosystems of southern Asia and are heavily exploited for their skins and meat. We examined 216 specimens killed at commercial facilities in Cirebon, West Java, to quantify morphological and reproductive traits and evaluate harvest sustainability by comparing this sample to one taken 25 years previously. The snakes we examined were mostly adults, and mostly male. Females were less heavy-bodied than males of the same body length, matured at a larger size than males, but attained smaller maximum sizes. Reproduction and energy (fatbody) storage was seasonal in both sexes, with females containing oviductal eggs primarily during the annual wet season. Clutch size averaged 12.6 eggs and increased with maternal body size. Comparison of the two samples taken 25 years apart revealed strong similarity in sex ratio, the numerical preponderance of adults, body sizes at sexual maturation and mean adult body sizes, sexual dimorphism in body length and mass, reproductive seasonality in females, mean fecundity, and the relationship between fecundity and maternal body size. That consistency suggests that commercial harvesting over the intervening period has not affected the biological traits of rat snake populations, consistent with a sustainable level of offtake.

The koala (Phascolarctos cinereus) population in Australia has been subjected to numerous threats leading to a significant decline in their numbers. The Port Macquarie region serves as a vital habitat for these iconic marsupials. Analysing records of 1227 koalas admitted to the Port Macquarie Koala Hospital (2014–2022), this study aimed to understand admission causes, temporal trends, and risk factors. Anthropogenic activities accounted for almost half (49.7%) of all admissions with ‘dangerous area’ and ‘motor vehicle accident’ (MVA) being common aetiologies. Young koalas were more susceptible to ‘dangerous area’, ‘MVA’, and ‘dog attack’ than other age groups. Koalas admitted for suspected chlamydia were also a significant contributing factor for admissions, and was most common in young koalas. Overall, the majority of koalas were candidates for rehabilitation or release (54.3%), but mature and aged koalas had the highest odds for mortality. This study highlights the ongoing impact of anthropogenic activities on koalas, emphasises the need for public education and reporting to mitigate risks, and underscores the importance of addressing diseases like chlamydia. These results contribute to our understanding of the factors influencing koala hospital admissions and can inform conservation and management strategies for this iconic Australian species.

The stripe-faced dunnart (Sminthopsis macroura) is one of the most widespread dasyurids in Australia, occurring mostly in semiarid and arid habitats. It is not known to inhabit coastal regions of southern Australia, and no records have previously been recorded from latitudes greater than 28.5°S in Western Australia. Following the capture of an individual south of the known species range provisionally identified based on external morphology as S. macroura, we used DNA and craniodental morphology to corroborate the specimen’s identification, providing a record of the species at Eucla, Western Australia. This represents a large range extension for S. macroura of 630 km from the nearest confirmed records of the species in Western Australia and South Australia.

The aim of this investigation was to explore the effect point of capture has on relative weight (Wr), as well as haematology and biochemistry values, in wild eastern longneck turtles (Chelodina longicollis). This study group consisted of two sites of turtles residing in Duck Pond (DP) and Ivanhoe Wetland (IW) in the Darebin Parklands, in Alphington, Melbourne. From DP, 184 turtles were captured, and from IW, 37 turtles were captured. All turtles were weighed and measured, and a random subset of 20 turtles from each waterbody was selected for blood collection. Significant differences were found to exist for Wr, basophils, glucose, uric acid, triglycerides and bile acids between the two sites. Serum glucose levels tended to decrease as a turtle increased in mass, straight carapace length (SCL) and Wr. The results of this investigation highlight the need to take location into consideration when assessing blood parameters in reptiles.

The conservation management of threatened wildlife increasingly relies upon translocations to augment populations. Translocations, however, pose various risks: from the host perspective these include the spread of parasitic disease, whereas from a broader biodiversity perspective translocation may lead to the loss of rare parasites and other dependent fauna. Although Disease Risk Analyses are recommended during translocation planning, knowledge regarding the parasites infecting threatened species or their pathogenicity is often lacking. Between March 2014 and June 2016, woylies (Bettongia penicillata) and sympatric marsupials were screened for the presence of endo- and ectoparasites, during two fauna translocations in south-western Australia. Here, we summarise the parasite taxa identified from B. penicillata, brush-tailed possums (Trichosurus vulpecula hypoleucus) and chuditch (Dasyurus geoffroii), including prevalence data for host, parasite taxon and site. Results from the opportunistic sampling of other species (Isoodon fusciventer, Phascogale tapoatafa wambenger, Tiliqua rugosa and Felis catus) are also presented. New host–parasite records including Hepatozoon spp. from T. v. hypoleucus, Trypanosoma noyesi from T. rugosa, Ixodes australiensis and Ixodes tasmani from D. geoffroii, and I. australiensis and Amblyomma sp. from a P. t. wambenger were identified. This study highlights the importance of monitoring sympatric species, particularly when compiling baseline data of parasite fauna present within translocation sites and enhances our knowledge of parasites infecting terrestrial wildlife within Australia’s south-west, a Global Biodiversity Hotspot.

Temporary freshwater lenses can form in saline environments after rainfall, providing essential resources for species including drinking water and dispersal routes. However, there is limited indication that these lenses can also be used for breeding. Herein, we provide evidence of the green and golden bell frog, Litoria aurea, performing breeding activities, including calling and amplexus, in tidal mangrove creeks on Kooragang Island, NSW, Australia. Our findings suggest that these creeks intermittently phase into a low salinity state after the influx of fresh water from rainfall, forming temporary freshwater lenses that can be exploited before the creeks revert to a saline state. These lenses had salinities (1.4 ppt and 4.5 ppt) within the tolerance limit of L. aurea tadpoles, although we are unsure whether oviposition took place and offspring survival to metamorphosis was achieved. It is possible that anthropogenic disturbances to hydrology on Kooragang Island have benefited L. aurea by restricting tidal influences in mangrove creeks, prolonging the duration of freshwater lenses.

Storms can have significant impacts on wildlife and many animals, including birds, can predict a storm’s arrival and change their behaviour accordingly. Storms are often associated with changes in environmental variables, particularly with a fall in barometric pressure. Social animals may collectively detect and advertise the potential onset of inclement weather to facilitate group responses. The present study tested the hypothesis that the sulphur-crested cockatoo uses environmental cues to predict the onset of storms and communicates this to conspecifics by emitting a specific ‘rain call’. Field observations were made over a four-month period at four locations in greater Sydney. Cockatoo calls were recorded, along with multiple environmental variables: barometric pressure, relative humidity, rainfall and temperature. We also noted the time of day relative to sunrise and sunset. We found that rain calls occurred throughout the day but were most prominent at dawn and were far more common at two of the four study sites. Rain calls were more likely to occur at slightly lower temperatures, during periods of high humidity and if it was currently raining. We found no evidence that the calls were prompted by current atmospheric pressure, but the observation period did not contain many storms.

Wildlife clinics play a critical role in safeguarding the well-being and survival of diverse animal species, but their admissions data are also valuable for investigating threats and challenges impacting local wildlife. This study examines 10 years of admissions data from the Phillip Island Wildlife Clinic in Victoria, Australia, to identify species, primary causes, outcomes, and temporal trends of clinic admissions. Avian species constitute the majority of admissions (64.5%), with sea and water birds being the most frequently admitted group. Motor vehicle accidents, injuries of unknown cause, and orphaning are the dominant causes of admission for birds and mammals. Car strikes are the leading cause of admission for land birds, land mammals, macropods, and turtles. Orphaning exhibits a seasonal pattern, with a higher number of cases in spring. Overall, 59.1% of admissions resulted in mortality, with causes related to trauma showing significantly higher mortality risks than others. The findings emphasise the impact of tourism on wildlife populations and the urgent need for targeted conservation strategies on Phillip Island.

Oral baits containing vaccines, medicants or toxicants have been delivered to a broad range of wildlife species to protect against or treat disease, or suppress populations. Ethyl-Iophenoxic acid (Et-IPA) is used as a biomarker to determine oral bait consumption by wildlife species to assess and refine baiting strategies. Et-IPA is a persistent biomarker in many eutherian mammal species but not in the two marsupial species, swamp wallaby (Wallabia bicolor) and brushtail possum (Trichosurus vulpecula), tested to date. Et-IPA has not previously been evaluated in carnivorous marsupials. The Tasmanian devil (Sarcophilus harrisii), the largest extant carnivorous marsupial, is threatened by devil facial tumour disease (DFTD). Development of an oral DFTD vaccine bait is underway. In this study, eight devils were fed between 1 mg and 50 mg Et-IPA via oral baits to assess the effectiveness of Et-IPA as a serum biomarker for this species. Using liquid chromatography with tandem mass spectrometry, serum Et-IPA was detected in the devils up to 206 days after ingestion. This study demonstrates the utility of Et-IPA for estimating oral bait consumption by devils, the first carnivorous marsupial species to which this applies.

The echidna (Tachyglossus aculeatus) is documented as a new native predator of freshwater turtle eggs, particularly those of the vulnerable Fitzroy River turtle (Rheodytes leukops), and the critically endangered white-throated snapping turtle (Elseya albagula). This depredation has been identified in the Fitzroy, Burnett and Mary Catchments with echidnas recorded at traditional turtle nesting banks using direct observation of depredation of eggs, remote camera footage and identification of tracks. Echidnas were observed at traditional nesting banks for E. albagula and R. leukops nesting across eight months of the year. The presence of echidnas was more frequent during the R. leukops nesting season in spring. R. leukops is endemic to the Fitzroy Catchment and the depredation rate of eggs was significantly higher than for other species and catchments. The mean top egg depth of R. leukops nests was found to be the same depth as the echidna’s beak length. There was a significant increase in depredation during the five-year study period, with 47.4% of R. leukops clutches depredated by echidna in the 2022 season. This substantial loss of eggs and recruitment of hatchling turtles poses a significant threat to the populations of this threatened species.

Most forests and woodlands of south-eastern Australia are fire prone. These landscapes are typically dominated by tree species of the genus Eucalyptus, and many of these are proficient epicormic resprouters after fire. Several marsupial folivores rely on Eucalyptus foliage, including the koala. Little is known about the nutritional composition of epicormic leaves and whether folivores can utilise them. Following the 2019–20 megafires, we offered koalas epicormic leaves from eight eucalypt species that occur in the New South Wales Southern Tablelands and measured concentrations of foliar chemical constituents known to influence koala feeding (total and available nitrogen, formylated phloroglucinol compounds (FPCs), and unsubstituted B-ring flavanones (UBFs)). Captive koalas ate epicormic leaves from the four eucalypt species belonging to the subgenus Symphyomyrtus but ate relatively little from the species of the subgenus Eucalyptus. Available nitrogen was significantly higher in symphyomyrtle epicormic regrowth than in monocalypts and differed between species. Concentrations of FPCs and UBFs also differed between eucalypt species. Our results suggest that post-fire epicormic regrowth from symphyomyrtle species may be more readily browsed than that of monocalypts by koalas in the NSW Southern Tablelands. Therefore, some burnt areas are likely to be better quality habitat for koalas than others.