Across all landscape types, environmental managers work with communities to conserve biodiversity. The effectiveness of conservation practice, however, relies on acknowledging differences in preferences and values of nature. Implementing urban conservation is challenging because cities have diverse social, cultural and ecological attributes, meaning there are no simple solutions for the management or co-management of biodiversity. There is little guidance for urban environmental managers on how to 1) engage local urban communities and 2), implement conservation actions specific to cities and their communities. We conducted semi-structured interviews with 27 environmental managers from government and not-for-profit organizations across five Australian capital cities to 1) explore how environmental managers engaged local communities, and 2) understand the factors that enabled or constrained that engagement in conservation. Our aim was to understand the enablers and constraints of engagement with a view to share insights and patterns in the context of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) conceptual framework’s recognition of the diversity of values associated with nature’s contributions to people (NCP). We found that urban environmental managers facilitated NCP by working to improve people’s relationship with nature. Interviewees reported a range of enablers for community-based biodiversity conservation, including supportive organizational policies and strategies, community support, engaging Indigenous advisory groups, and deploying multi-use, integrative human-nature designs. Constraints and challenges included a lack of top-down commitment, reliance on individuals, and overly simplistic engagement strategies. Based on these findings, we identified opportunities for improved community engagement relevant to organizations responsible for urban environmental management.

Biological invasions can modify the behaviour of vulnerable native species in subtle ways. For example, native predators may learn or evolve to reduce foraging in conditions (habitats, times of day) that expose them to a toxic invasive species. In tropical Australia, freshwater crocodiles (Crocodylus johnstoni) are often fatally poisoned when they ingest invasive cane toads (Rhinella marina). The risk may be greatest if toads are seized on land, where a predator cannot wash away the toxins before they are absorbed into its bloodstream. Hence, toad invasion might induce crocodiles to forage in aquatic habitats only, foregoing terrestrial hunting. To test this idea, we conducted standardised trials of bait presentation to free-ranging crocodiles in sites with and without invasive toads. As anticipated, crocodiles rapidly learned to avoid consuming toads, and shifted to almost exclusively aquatic foraging.

In tropical Australia, conditioned taste aversion (CTA) can buffer vulnerable native predators from the invasion of a toxic prey species (cane toads, Rhinella marina ). Thus, we need to develop methods to deploy aversion‐inducing baits in the field, in ways that maximize uptake by vulnerable species (but not other taxa). We constructed and field‐tested baiting devices, in situ with wild animals. Apparatus were set next to waterbodies and baited concurrently at multiple locations (over water, water's edge, and on the bank). Baits were checked and replaced twice daily during the trial; remote cameras recorded visitation by native predators. Bait longevity was compared at sun‐exposed and shaded locations over 12 h. The strength required to remove baits from apparatus was measured in varanids and crocodiles. The device promoted high rates of bait uptake by freshwater crocodiles (47% baits consumed), varanid lizards (19% baits consumed), and non‐target taxa (34% baits consumed). Targeting specific predators can be achieved by manipulating bait location and time of deployment, as well as the force required to dislodge the bait. Crocodiles were best targeted with over‐water baits, whereas varanid lizards preferred baits located at the edges of waterbodies. When testing bait longevity in ambient conditions, during the daytime baits desiccated fully within 12 h, and faster in the sun than in the shade. Based on studies using captive animals, the “pulling force” strength of reptilian predators scaled with body size and was greater in crocodiles than in varanid lizards. We present the first conservation baiting protocol designed specifically for reptiles. Our results demonstrate the feasibility of widespread and taxon‐specific deployment of aversion‐inducing baits to buffer the impacts of invasive cane toads, and our methods are applicable (with modification) to other research and management programs globally.