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Background: The northern bettong, Bettongia tropica, is an endangered potoroid recognised as a specialist consumer of underground ectomycorrhizal fungi important to wet sclerophyll forest at the interface with tropical rainforest. In line with identified recovery objectives of re-establishing populations within the species' former range, a founder population was translocated to a feral predator-free fenced exclosure within previously occupied habitat to the south of its current range. No published reference intervals for haematology and serum biochemistry exist for this species. Establishing reference intervals provides a valuable tool for health assessment of founder animals and investigations into population health and disease during ongoing monitoring of populations., Objective: To develop reference intervals for haematology and serum biochemistry parameters in northern bettongs, Bettongia tropica., Methods: Haematological and serum biochemical reference intervals were determined from 39 healthy northern bettongs captured across the Lamb Range region of north Queensland. Routine haematological and biochemical parameters were analysed, including blood gases and lactate, which indicate metabolic changes associated with stress., Results: Haematological and serum biochemical parameters were similar to those reported from other potoroids, except for haematocrit and serum protein, which were elevated. Stress parameters were within normal limits. Macropod herpesvirus and Toxoplasma gondii were not detected., Conclusions: Translocated northern bettongs were in good general health, and data collected at the time of capture were sufficient to establish a preliminary reference interval for the species. This provides baseline information by which to monitor health and welfare of the translocated population, and will contribute to health monitoring of other extant populations., (© 2025 The Author(s). Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.)

Background: As a ubiquitous apicomplexan parasite, Toxoplasma gondii causes huge economic losses and poses a great threat to the health of animals, including humans, worldwide. In some kangaroo species, T. gondii can be fatal. To date, little information is available on T. gondii infection in the red kangaroos in east China. At a zoo in east China, thirteen red kangaroos consecutively developed clinical signs from July to November 2016, resulting in the deaths of seven, three of which were analyzed in this study. Methods: In the present study, ascitic fluid, blood and samples from the brain, heart, liver, spleen, lung, kidney, and mesenteric lymph nodes of three dead red kangaroos were collected. The pathogen was explored through microscopic observation, nested PCR, immunofluorescence antibody test (IFAT), hematoxylin–eosin (HE) staining, and immunohistochemistry (IHC) staining, respectively. Meanwhile, the potential source of the infection was also investigated by testing the blood of stray cats in the zoo for T. gondii using nested PCR. Results: Three dead red kangaroos were subjected to a necropsy, and organisms resembling T. gondii were detected in their ascitic fluids under microscope. This infection was further confirmed by a nested PCR assay, which resulted in a successful amplification and sequencing of the 433 bp fragment of the T. gondii 5.8S rRNA gene in all the dissected tissues, including heart, liver, spleen, lung, kidney, lymph nodes, cecum, and brain, as well as in body fluids (blood and ascitic fluid). Furthermore, the tachyzoites were observed in the heart, liver, spleen, lymph nodes, cecum, and brain through IFAT and HE staining. Administration of classic drugs (sulfadiazine and pyrimethamine) against T. gondii significantly alleviated the clinical signs of the sick kangaroos. The possible source of this infection was traced to a native stray cat, as T. gondii DNA was detected in its blood. Conclusions: In the present study, lethal T. gondii infection in red kangaroos has been described for the first time in east China, highlighting the necessity and urgency for close and long-term surveillance of this parasite infection in captive animals. The same strain of T. gondii detected in kangaroos as that found in stray cats wandering in the same area emphasizes the importance of controlling stray cat populations to mitigate the risk of Toxoplasma transmission to other animals. [ABSTRACT FROM AUTHOR]

Context: Aerial distance sampling surveys are a widely used approach for estimating the abundance of wildlife populations, including kangaroos and other macropods. When analysing such data, design-based estimates of abundance extrapolate density from the sampled region to the broader area. In contrast, model-based approaches that use relationships between population density and habitat variables can deliver greater precision and ecological insight into population estimates. Aims: This study aimed to evaluate recent spatio-temporal trends in the abundance of grey kangaroos (Macropus giganteus and M. fuliginosus) in Victoria, Australia using both design-based and model-based distance sampling. Methods: Aerial surveys were conducted in seven management zones spread across the non-forested parts of Victoria on four occasions between 2017 and 2022. Distance sampling data were analysed to obtain design-based and model-based estimates of population size and relative precision across the entire study area, and for each management zone for each of the four surveys. Key results: Model-based and design-based estimates of abundance proved to be broadly comparable, but with mostly higher precision for the model-based estimates at both statewide and management zone scales. The model-based approach revealed relationships between transect-level abundance and land-use type, normalised difference vegetation index (NDVI), annual rainfall and the amount of ecotonal habitat in the vicinity of the transects. Between 2017 and 2022 (a period coinciding with a prolonged La Niña event), the total abundance of grey kangaroos increased by approximately 87% (based on the model-based inferences) despite an ongoing harvesting program. Conclusions: In addition to improved precision, model based estimation revealed relationships between habitat variables and transect-level abundance, allowing prediction of abundance at small scales. Implications: The improved precision of model-based estimates of abundance will provide greater confidence in kangaroo management decisions such as setting of statewide harvest quotas. Model-based estimates at smaller spatial scales will similarly support localised management decisions. Aerial distance sampling surveys for eastern and western grey kangaroos were conducted across Victoria between 2017 and 2022. Using a model-based approach we were able to infer spatial and temporal trends in abundance across the study area during this period. Grey kangaroo populations generally increased over the course of the study. The model-based approach mostly yielded more precise population estimates than previously used design-based approaches, as well as providing insight into ecological drivers of abundance. Photograph by Justin Cally. [ABSTRACT FROM AUTHOR]

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. Weak links installed on radio collars are devices designed to protect animals from entanglement during animal studies and allow remote retrieval of the collar after study. We tested a latex weak link on collars used to track eastern grey kangaroos and found that it was able to successfully achieve both functions on all animals. Future researchers can use weak links of similar design to provide good welfare for animals involved in research. Photograph by Tian Chen. [ABSTRACT FROM AUTHOR]

Simple Summary: Colourful animals are often more conspicuous than dull animals, which increases their exposure to predators. One way to reduce predation risk could be to be more vigilant. We investigated this in two related songbird species, the colourful Gouldian finch and the less colourful long-tailed finch, at waterholes by measuring the frequency of head movements as a measure of vigilance. Both species showed a high frequency of head movements (high vigilance) when sitting in an open tree where they could be easily spotted. However, the more conspicuous Gouldian finch remained more vigilant when sitting under cover than the long-tailed finch. Moreover, juveniles and adults of the Gouldian finch had similar vigilance levels; whereas, juvenile long-tailed finches were less vigilant than their adult counterparts, possibly because of the juveniles often being in family groups. Both species showed a similar reduction in vigilance shortly after landing in the tree. The reduction in vigilance was affected by group size. This indicates initial uncertainty about the threat they might face, more so when alone. Finally, vigilance was higher at small waterholes, reflecting a higher perceived risk, as compared to larger waterholes. Conspicuousness increases the risk of predation. One strategy to reduce this risk is to increase vigilance. We investigated the frequency of head movements as a measure of vigilance at waterholes in two related songbird species that differed in their conspicuousness: the Gouldian finch and the long-tailed finch. While both species showed a high frequency of head movements (high vigilance) when sitting in an open tree, the more colourful Gouldian finch remained more vigilant than the less conspicuous long-tailed finch when sitting under cover. Moreover, juvenile Gouldian finches had similar vigilance levels than adults; whereas, juveniles of the long-tailed finch were less vigilant, possibly because of staying in the family group. Furthermore, both species showed a similar temporal course of vigilance with a fast decrease in vigilance after landing in the tree, which was affected by group size. Single individuals had much higher vigilance than groups of birds. Finally, vigilance was higher at small waterholes. The results show that conspicuousness, uncertainty when arriving at waterholes, and higher perceived risk at small waterholes increased vigilance. [ABSTRACT FROM AUTHOR]

Context: Macropods are very susceptible to stress during capture. Capture methods for macropods fall into two categories: trapping and darting. Trapping by nets or a triggered trap mechanism is commonly used for small macropods. Darting is most often used for large macropods that are more prone to stress and capture myopathy when caught in traps. Aim: To describe a modified 'nylon drop-net' technique for safely capturing medium to large macropods; and post-capture treatments that reduce stress and the potential for myopathy. Methods: We used a drop-net to capture 40 agile wallabies (Notamacropus agilis) (24 females and 16 males), ranging in weight from 6 to 24 kg. For immobilisation, a single dose of intramuscular Diazepam (1 mg/kg) and Richtasol, a multivitamin, was administered to reduce the risk of capture myopathy. The longer-term effects of capture on animal condition were monitored in 34 radio-collared individuals for 2 months. Key results: No deaths occurred during or as a result of capture or in the 8 weeks following capture. Conclusions: Our modified drop-net and handling/treatment regime provides a cost-effective method for capturing medium and small-sized macropod species with very low risk of mortality or morbidity. Implications: Our methods improve the welfare and safety of captured medium-sized macropods. Macropods are prone to stress during capture, making the development of capture methods challenging. Currently, the most common methods used are trapping, suited for small macropods, and darting for the larger ones. A modified 'nylon drop-net' technique, typically used for African ungulates, was successfully employed to capture 40 agile wallabies with no fatalities during or after the procedure. Photograph by Miguel A. Bedoya-Perez. [ABSTRACT FROM AUTHOR]