Macropods (kangaroos and wallabies) have reached hyperabundant levels in many areas. The aims of this presentation are to outline the symptoms, diagnose the probable causes and evaluate options for managing hyperabundance in macropods. There are many symptoms of hyperabundance. Macropods can inflict costs to human livelihood through competition with domestic stock and losses to cropping and horticulture, as well as posing a risk to life through vehicle collisions and attacks and people and their dogs. Macropods can also threatened biodiversity through overgrazing, leading to loss of vegetative cover, altered community composition and soil erosion, with secondary impacts on dependent fauna. In some cases, macropods can undergo population irruptions, culminating in poor body condition, high disease prevalence, reproductive failure and mass mortality events. The underlying causes of macropod hyperabundance are loss of ecological feedback. Bottom-up control has been distorted by canopy tree clearing, pasture improvement and artificial water, increasing habitat suitability and carrying capacity for many grazing species. Top-down control has been lost through extirpation of predators across arable and pastoral landscapes, as well as many reserved areas. Management of macropod overabundance is based on either damage mitigation or population control. Of the mitigation methods available, exclusion is effective but localised and costly, diversion is promising but unproven at scale, and deterrence is blighted by unfounded claims and dubious science. Population control is controversial and challenging. Fertility control is the favoured non-lethal approach, and is effective for small and ideally closed populations, but is costly. Shooting is the most effective method for lethal control but is divisive, particularly in peri-urban settings, and culling effort must be maintained to counteract density-dependent demographic changes in macropod populations.

Many properties in arid Australia that were once used for livestock grazing have been converted to conservation reserves with a key objective being to restore ecosystems by functioning as a refuge from livestock grazing. However, properties whose land use transitions from pastoralism to conservation inherit legacies of earlier pastoral enterprises such as fences and artificial water points (AWP). AWP have fundamentally changed the availability of surface water for wildlife in arid landscapes by making water available all or most of the time in places where water was naturally only available for brief periods following irregular rainfall events. Many herbivores that inhabit arid lands will drink if water is available and some species concentrate their activity around AWP. Thus, excessive trampling and consumption of forage by herbivores can lead to the degradation of areas near AWP. Consequently, managers of conservation reserves have expressed concern that AWP may exacerbate the grazing impacts of kangaroos. Here, we investigate the effect that surface water has on the distribution of red kangaroos using satellite imagery and aerial surveys conducted over three survey periods on Witchelina Nature Reserve. The availability of surface water varied between survey periods and was greatest during periods of wet climatic conditions and least during drought. Kangaroo abundance varied between survey periods and was lowest during extreme drought. During wet periods, kangaroos were most abundant on stony plains and their abundance in survey blocks was not related to distance from water. During extreme drought, kangaroo abundance did not differ between habitats but decreased with increasing distance from AWP that held water. These results suggest that proximity to water influenced the distribution of kangaroos during drought. Our findings suggest that decommissioning water points or excluding kangaroos from water may have merit as a strategy to reduce kangaroos grazing and trampling impacts during drought.

The 3-year project Future-Proofing Little Penguins Project on Summerland Peninsula, Phillip Island, begun in 2023 with the aim of building the resilience of the Little Penguin colony and other wildlife against heatwave events and to reduce the risk of bushfire from devastating populations by modifying habitat to make it cooler and less flammable. The project is managed by Phillip Island Nature Parks and supported by $500k in funding from multiple funding agencies.

The need for this work followed many years of local research including studies of how penguins cope with heat-stress and of how important habitat (nest) quality was in this regard, and fire modelling and risk analysis. The project was pitched as a climate-change adaption initiative but was effectively planned as a traditional revegetation program involving large scale plantings of indigenous fire-retardant herbaceous plant species and trees and shrubs. This included some clearing and revegetation for the purpose of establishing ‘green’ firebreaks but otherwise supplementary planting within natural but previously disturbed landscapes.

So, what do you do when the project doesn’t go to plan, and it becomes clear that the most basic goals and measures of success won’t be achieved but you are bound to funding and contractual obligations? Adapt.

When it became clear that plant survival rates would fall well below expectations due to browsing pressure from high populations of Swamp Wallabies and Cape Barren Geese then assessment of browsing impacts on conservation plantings and on native vegetation generally became a big focus and various trials, monitoring and research activities (that were originally unplanned) were quickly incorporated into the project. Methods of planting also changed in response with various planting trials undertaken to try to seek more effective conservation outcomes. Some of the challenges and key learnings to date of this project are presented.

Wild herbivores threaten vegetation recovery on dryland reserves . Monitoring herbivore impacts in drylands is difficult because vegetation biomass transitions between living and senescent states in response to irregular rainfall. However, land managers must understand the impacts that wild herbivores have on vegetation to develop effective management strategies. We used Sentinel-2 satellite imagery to investigate how grazing by kangaroos and rabbits impacted fractional cover of photosynthetic (green) and non-photosynthetic (senescent) vegetation over a 7-year period on three dryland reserves. We compared green and senescent cover in plots that were accessible to all herbivores, accessible to kangaroos only and inaccessible to both rabbits and kangaroos. Generalized linear mixed models were used to determine if the grazing impacts of rabbits and kangaroos varied from each other, between reserves, and in response to variable rainfall patterns. Grazing impacts varied between herbivores, conservation reserves, and between green and senescent vegetation. Green cover was only weakly limited by kangaroos. Senescent vegetation was limited by rabbits and kangaroos, with grazing having stronger impacts on senescent cover than green cover. The grazing impacts of rabbits and kangaroos varied spatially with evidence that senescent vegetation was limited by kangaroos only, by rabbits only, and by both species across different reserves. Both herbivores had stronger impacts on senescent vegetation as antecedent rainfall decreased. Our results show that the impact of herbivores on vegetation biomass is greatest during periods of dry climatic conditions. These findings contribute to a growing body of evidence showing that grazing by wild herbivores can have detrimental impacts on dryland ecosystems by disrupting ecological processes supported by senescent vegetation. We recommend that herbivore management interventions be undertaken during productive periods when grazing impacts are less likely to be observed to prevent unsustainable grazing pressure from wild herbivores during subsequent low rainfall periods.

Overabundant impact causing macropods have been a divisive topic in Australia for over half a century. After multiple flooding events of the early 2010s, followed by years of large macropod species reaching unsustainable population levels, the 2018-2019 drought triggered a widespread starvation event with millions of kangaroos lost to the deleterious conditions. The Kangaroo Partnership Project was created from the outcry by those who witnessed this sequence of unnatural and exaggerated boom and bust cycles. The project is supported through the Landscapes Priority Fund and by the South Australian Drought Resilience Adoption and Innovation Hub, through funding from the Australian Government’s Future Drought Fund. The aim of the project – improved kangaroo management outcomes through a collaborative model that respects animal welfare, cultural, conservation, environmental, economic and social values, connecting communities and partners.
Now entering its second phase, the collaborative partnership model continues to unite landholders, producers, industry, conservation and agricultural organisations, government departments, First Nations and animal welfare groups. Through the combined perspectives, specialist knowledge and lived experience of these stakeholders the project is continuously reassessing, strategically planning and shifting to meet common ground on a future forward-facing path. Recent initiatives to support novel projects, renewed on-ground and online engagement opportunities and communities of practices are some of the steps helping to address the current barriers that prevent effective kangaroo management. The Kangaroo Partnership Project continues to tackle the complexity of the ‘wicked’ issue of overabundant macropods through the foundation of the collaborative model.

Cape Barren Geese (Cereopsis novaehollandiae) represent a remarkable conservation story in Australia. Once threatened with extinction, successful protection of this species has resulted in their numbers increasing and range expanding, particularly in southern Victoria. However, the current population, which is centred on Millowl (Phillip Island) and French Island, is considered overabundant and growing numbers have resulted in conflict with agricultural and conservation practices on the islands. Despite being conspicuous and common, no detailed study has been conducted to investigate the movements, behaviour and breeding of this population. Understanding this population’s basic ecology is essential to inform future management to reduce its impact on agricultural and conservation practices, while still maintaining a viable population of Cape Barren Geese in southern Victoria.

To fill knowledge gaps on Cape Barren Geese ecology in Victoria, we deployed 100 biologgers onto geese on Millowl in spring 2024. Using location and behaviour data from these biologgers we have been able to determine how individual geese use and move between paddocks on Millowl and southern Victoria over the past year. We have also been able to determine daily activity budgets of geese from behaviour data collected by the biologgers, and compare activity budgets between males and females, as well as first year and adult geese to determine which sex and age groups are having the most significant grazing impact on agriculture. This data has provided new insights into the previously unknown ecology of overabundant Cape Barren Geese in southern Victoria and their impacts on agriculture. The understandings that come from this data will be crucial for current and future management of this population on Millowl and throughout southern Victoria.

Roosts provide animals with places for protection, breeding, and social benefits. However, roost availability is a critical issue for urban-dwelling animals due to habitat degradation, such as deforestation. Animals within low roost availability areas may aggregate in one single roost to benefit information transmission and collective defence. In contrast, animals within high roost availability areas may form multiple subgroups to reduce competition and maintain reciprocal benefits. Most microbats selectively aggregate with familiar roost mates, possibly recognising them through vocal communication, and roost in either tree hollows or compensatory artificial boxes in urban areas. Gould’s Wattled Bat, Chalinolobous gouldii, an urban-adapted species, predominantly inhabit and use artificial roosts in urban green spaces. They also regularly aggregate during breeding seasons, forming stable roosting groups. Despite this, little is known about how roost availability influences their social networks, and how social networks contribute to variation in vocal communication. In this study, we used capture-recapture from 2022 to 2025 to construct social networks and record C. gouldii social vocalisations around potential roosts within three green spaces in Sydney. We found that bats formed a high-density social network consisting of a single group in an area with low roost availability, whereas they formed lower-density social networks with multiple subgroups in areas with greater roost availability. We found evidence of geographic variation between locations; however social network density did not lead to significant variation among their social vocalisations. These findings suggest that indicators of habitat quality such as roost availability can influence bat social networks. Dense social networks potentially amplify information transmission but could also increase disease transmission risk between individuals in anthropogenic environments. This research suggests land managers should focus on improving roost availability to maintain social connectivity among microbat populations.