Zoos Victoria

Multiple paternity in litters and a female’s choice of mate can significantly influence siring success and the success and survival of offspring. In captive agile antechinus (Antechinus agilis), a small, carnivorous marsupial that exhibits obligate semelparity, females choose to mate with multiple males and mate choice is profoundly influenced by genetic dissimilarity between mates, not male size. However, female mate choice has not been examined in wild agile antechinus. Our study encompassed one year in which the operational sex ratio was at parity and a second in which the ratio was female biased, and animal weight, survival and litter size were significantly decreased due to severe drought conditions. Using genetic data from 204 pouch young, we show that genetically dissimilar males sired a higher proportion of young when the sex ratio was at parity, but there was no influence of relatedness on siring success during drought conditions. Larger males sired a higher proportion of young in both years, suggesting that female choice may be partially over-ridden by male behaviour. We highlight concerns for semelparous marsupials during increasingly frequent environmental disruptions, including drought, which could influence mate choice behaviours, reproductive success, genetic health and population survival.

Following bushfires (also known as wildfires), impacted free-living wildlife with welfare or conservation concerns are captured and presented for veterinary assessment where possible. This study represents an in-depth retrospective analysis of the veterinary records of 259 animals in Victoria, Australia, impacted by bushfire in 2019-2020. In total, 35 different species were assessed, including 196 koalas. Multivariable analyses of 126 koalas with complete medical records identified several clinical prognostic factors affecting 6-month survival outcomes. Increased odds of negative outcomes (death or euthanasia) were associated with increasing age (tooth wear class; odds ratio 2.70 for one unit increase), lower body condition score (one-unit decrease OR 7.27), and the earlier animals were presented after the fire event (OR 0.94 for each passing day). In 83 koalas with burn injuries, negative outcomes were also associated with burns more severe than minor (85% survival for minor burns only, compared to 31% survival with moderate or severe burns), and burns to more than 10 digits (12% survival). In burnt koalas, the combination of burn severity and digital involvement appear to be important prognostic factors for long-term outcomes. These findings can support veterinarians to more accurately evaluate prognosis for bushfire-affected koalas during initial assessment and will facilitate the strategic allocation of limited treatment and rehabilitation resources to the animals most likely to recover. The scope of this study was limited to the consideration of health outcomes, with the recognition of health as just one of many factors that must inform decisions about rehabilitating injured wildlife.

The mainland eastern barred bandicoot (Perameles gunnii) has been the subject of a recovery effort since 1988 due to threats posed by introduced predators and habitat destruction. Despite a concerted effort to recover the species, they came perilously close to extinction in the early 2000s. A change of tactics and securing populations in multiple fox-free safe havens was required to save the species from imminent extinction. Through the release of eastern barred bandicoots onto Phillip and French Islands, made possible by support from the local island communities, the trajectory of eastern barred bandicoots has been reversed. They are now widespread and abundant across both islands, and in 2021 were reclassified from ‘Extinct in the Wild’ to ‘Endangered’ largely due to these island releases. However, this does not mean that the eastern barred bandicoot is secure and no longer requires management. As mainland eastern barred bandicoots only occur within safe havens, which have a history of intermittent incursions and failure, it is essential that sites remain vigilantly monitored and managed to secure the species and the hard-won conservation gains. We document the lengthy process of releasing eastern barred bandicoots onto Victoria’s two largest islands, including assessing suitability, garnering community support and managing uncertainties.

Recent catastrophic climate events in Australia that have impacted millions of animals across a range of landscapes have initiated a need for planned and coordinated rescue responses. The platypus (Ornithorhynchus anatinus) is one of Australia’s most iconic and biologically significant species. At a workshop held at Healesville Sanctuary, Victoria, Australia in 2023, species experts discussed the greatest threats, scenarios where intervention may be required and the types of intervention options that may be suitable for platypuses. We consider drought to be the most concerning event for the species, along with the impact of cumulative events on their habitat over time. Here, we discuss how intervention criteria should consider the degree of habitat impact, the recovery time frame, the genetic importance and local extinction risk of a population, risks to animal welfare, and the capacity requirements and feasibility of resourcing any action. Suitable interventions are weighed against potential risks and include the rescue and rehabilitation of displaced individuals, in situ habitat support, and translocation to either temporary ex situ care or inter or intra catchment. Further research is required to address how the platypus responds during and after different climate events, to different interventions and to determine which populations are most at risk. The outcomes discussed here and the framework provided should aid in management response decision making after natural disasters that may impact platypus populations.

Abstract Ecological monitoring plays a crucial role in conserving biodiversity. However, ensuring that monitoring programs possess adequate statistical power—the capacity to detect changes in populations with a high level of confidence—remains a significant challenge for wildlife managers worldwide. The rise in popularity of camera traps has led to a proliferation of models with varying costs, specifications, and capabilities. This diversity presents both opportunities and challenges for wildlife managers, as selecting the most suitable model requires careful consideration of detection probabilities, deployment durations, and overall cost‐effectiveness. Here, we present a case study comparing the performance of two commercially available camera trap models widely used for monitoring eight species groups within a global biodiversity hotspot. While Reconyx cameras demonstrated superior detectability for most species, the lower‐cost Swift models proved more cost‐effective for increasing statistical power in large‐scale monitoring programs. These results highlight the importance of comparing monitoring technologies using metrics that go beyond nightly detectability, such as statistical power, and evaluating these technologies at the scale at which they are intended to be implemented. These findings provide a framework for wildlife managers to optimize monitoring programs while balancing cost and performance.

Zoos are interested in assessing the well-being of the animals in their care, including potential impacts from environmental and anthropogenic factors which could alter welfare. Zoos also provide a unique environment whereby visitors can get within proximity to wild animals, which can have positive, neutral, or negative impact for the exhibited animal's welfare. Within zoo settings, there has been little research published on these welfare impacts for reptiles, specifically snakes. Additionally, there is limited knowledge on their behavior in relation to captive welfare. Three snakes were selected, and conditions were implemented outside of their habitats to alter visitor proximity. The three conditions experimentally altered the proximity of people near the snake habitats and included Visitor-Natural (regular visitor proximity), Visitor-Control (no visitors within a 210 cm radius), and Visitor-Experimenter (an experimenter within close proximity throughout the observation time). An ethogram was developed and measured across a within-subject reversal design for all three conditions. Results indicated that overall, there was a neutral to positive impact of the Visitor-Natural condition. However, the highest negative impacts were observed during the Visitor-Experimenter condition, including increased abnormal behaviors. This study suggests that snakes will habituate to people but may be affected by short-term, unpredictable behavior from visitors. The results are discussed in terms of visitor impacts on exhibited snakes, as well as implications for assessing overall snake welfare.