Caragh Grace Threlfall

Quantitative data on habitat use enable defensible conservation management, yet such data are lacking for many threatened species. Using the endangered large‐eared pied bat ( Chalinolobus dwyeri ) in eastern Australia as a case study, we deployed dense acoustic arrays comprising 188 AudioMoth recorders across seven sites (25–29 recorders per site) to quantify fine‐scale habitat use in human‐modified landscapes. Generalized additive mixed models revealed distinct but broadly consistent habitat responses for both total and feeding activity. For total activity, 80% of the fitted decline occurred within 248 m of substantial rocky habitat, 405 m of freshwater and 82 m of roads/tracks, likely reflecting their role as linear vegetation edges. Activity also peaked at intermediate edge density and increased substantially when woody vegetation cover measured within 100 m exceeded 72%. Feeding activity was not associated with rock outcrops/cliffs, indicating foraging typically shifts away from roosts into surrounding habitat. Instead, 80% of the fitted decline occurred within 376 m of freshwater and 18 m of roads/tracks. Feeding activity also peaked at intermediate edge density measured within 100 m and increased when woody vegetation cover within 200 m exceeded 58%. These findings support baseline protection distances of 250 m around rocky roosting habitat, an additional 100 m protection zone from the outer edge of adjoining roost‐associated woody vegetation, and protection of freshwater sources associated with roosting habitat. These distances are starting values that should be refined through project‐specific risk assessment rather than applied as universal thresholds. We also propose an acoustic screening benchmark for maternity roosts: an active roost within approximately 100 m is considered unlikely during the survey period if at least two well‐positioned ultrasonic recorders at separate likely flyways each average <30 calls/night over at least four suitable nights. Together, these results provide an adaptable framework for translating activity patterns into defensible survey and impact‐assessment guidance for acoustically identifiable taxa.

Parasitoid visitation occurs in both natural and artificial Hymenopteran nesting cavities, such as those that occur in bee hotels. Detection of parasitoids emerging from these cavities can provide information on the extent and abundance of their associated hosts. However, adaptive bee hotel management may be required to prevent these structures from becoming a population sink if extensive parasitoid emergence is detected. Detection of the invertebrates that emerge from occupied cavities in bee hotels can be hard to determine. Microwasps, one group of parasitoids, can be even harder to detect due to their small size. In this research, we proposed a non‐destructive, early in the field detection method to estimate microwasp parasitoid abundance and presence from the observation of emergence holes. Bee hotels were deployed in areas subject to ecological restoration within the Cumberland Plain Woodland of the Greater Sydney Region. The emergence of bee hotel occupants was recorded, with target taxa identified to genus. Emergence of the microwasp Eulophidae cf. Beornia in most cases resulted in no emergence of a primary occupant. However, in a few novel cases, Eulophidae cf. Beornia did emerge alongside Pison and Anterhynchium wasps. When Eulophidae cf. Beornia emerged from cavities, while the sealed entrances remained intact, small emergence holes were detected in the front and rear sealed cavities. These emergence holes offer a way for practitioners that use bee hotels to estimate microwasp parasitoid presence and abundance. Understanding this can also provide insights into the presence and abundance of their associated hosts. This method can indicate if the deployed bee hotels are supporting invertebrate populations, or overly facilitating parasitoid numbers, resulting in the bee hotel acting as a sink. Early detection of excessive parasitoid numbers can allow for practitioners to employ adaptive management actions to ensure the bee hotels are supporting local populations.

Since its consolidation as a sub‐discipline of ecology in the late 1990s, urban ecology has grown substantially, enhancing our understanding of how urbanization shapes biodiversity and how biodiversity adapts to urbanization. Inherently interdisciplinary in its scope and application, urban ecology is rooted in multiple theoretical and methodological foundations, potentially making the field overwhelming for newcomers as the key literature is scattered across multiple disciplines. Drawing on the collective expertise of editors and reviewers, we attempt to address common pitfalls noted in studies of biodiversity within urban ecosystems and suggest action items for both the new and experienced urban ecologist. Here, we present key concepts for framing hypothesis‐based urban biodiversity research questions, conceptualizing urban settings, accounting for spatial and temporal scales, selecting study systems and meaningful explanatory variables for research questions, and recognizing the social‐ecological nature of urban systems. We offer insights and examples, emphasizing the importance of rigorous urban ecological research without imposing constraints on innovation.

Distinct behaviours between males and females within the same species can promote differences in the use of resources between sexes, which can have profound consequences on ecosystem processes, such as pollination. Despite this, studies on floral visitation often focus on the relationships between floral visitors and plants at the species level, neglecting the intraspecific differences between male and female insect floral visitors. This study investigates intraspecific differences in the use of floral resources by male and female Melangyna , a dominant group of hover flies. Our year‐long observations reveal distinct behaviours in hovering and foraging between the sexes and among the seasons. We also present evidence of sexual dimorphism, with males being larger than females. These behavioural and physical differences lead to distinct use of floral resources by each sex, which could have significant implications for plant reproduction. Our findings underscore the need to consider intraspecific sexual differences in future studies on floral visitation and pollination.

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α‐diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ‐diversity), either due to reduced β‐diversity amplifying diversity loss or increased β‐diversity dampening diversity loss. Additionally, studies often focus on taxonomic diversity, while other important biodiversity components, including phylogenetic diversity, can exhibit differential responses. Here, we evaluated how agricultural and urban land use alters the taxonomic and phylogenetic α‐, β‐, and γ‐diversity of an important pollinator taxon—bees. Using a multicontinental dataset of 3117 bee assemblages from 157 studies, we found that taxonomic α‐diversity was reduced by 16%–18% in both agricultural and urban habitats relative to natural habitats. Phylogenetic α‐diversity was decreased by 11%–12% in agricultural and urban habitats. Compared with natural habitats, taxonomic and phylogenetic β‐diversity increased by 11% and 6% in urban habitats, respectively, but exhibited no systematic change in agricultural habitats. We detected a 22% decline in taxonomic γ‐diversity and a 17% decline in phylogenetic γ‐diversity in agricultural habitats, but γ‐diversity of urban habitats was not significantly different from natural habitats. These findings highlight the threat of agricultural expansions to large‐scale bee diversity due to systematic γ‐diversity decline. In addition, while both urbanization and agriculture lead to consistent declines in α‐diversity, their impacts on β‐ or γ‐diversity vary, highlighting the need to study the effects of land use change at multiple scales.

Bat boxes are often installed as substitute habitats to offset the loss of large, hollow‐bearing trees. However, emerging evidence suggests that they are failing to achieve intended conservation outcomes as they only support generalist species. Despite these concerns, the effect of bat boxes on the dynamics of bat communities remains understudied. We assessed the bat community in reserves where bat boxes had been installed in comparison with reserves where they had not using ultrasonic surveys in 16 small bushland reserves throughout Sydney, Australia. Reserves containing bat boxes and those without had comparable species diversity and composition; however, the activity of the dominant species, Gould's wattled bat (Chalinolobus gouldii), was significantly higher at sites with bat boxes. Species that commonly forage in open vegetation, including C. gouldii, were significantly positively associated with sites that had bat boxes. Occupation of boxes by bats was not recorded in the study due to limited information on their locations, so further research is required to understand the direct effects of boxes and the bats that occupy them on the bat community. If bat boxes continue to be recommended as a biodiversity offset, a greater understanding of the potential impact they have on altered competitive relationships and community dynamics is essential.

Bats are a highly diverse and unique order of mammals, with many species persisting in cities. Their flight and echolocation abilities has enabled the diversification of ecological strategies within this group. Given their dependence upon habitat structure for navigation, they are very sensitive to habitat disturbance and hence make suitable bioindicators for environmental conditions in cities. To this end, there has been a proliferation of studies, using passive acoustic techniques in addition to radio-tracking studies, examining the response of bat species and communities to urbanisation. Many studies show an overall negative impact of urbanisation on bat activity and diversity, however there are some species that thrive. The most important elements of the urban landscape to many bat species include roosting sites (either natural or man-made), foraging and commuting sites, and water sources for drinking. Future research is needed into population level impacts of urbanisation, in addition to better understanding the traits that allow for adaptation to urban conditions. This knowledge is greatly needed to improve the conservation trajectory of urban bats, enabling bat-friendly city planning, design, and management.

Experimentally manipulating urban tree abundance and structure can help explore the complex and reciprocal interactions among people, biodiversity and the services urban forests provide to humans and wildlife. In this study we take advantage of scheduled urban tree removals to experimentally quantify the benefits that urban trees provide to humans and wildlife. Specifically, we aim to understand how trees affect: (1) bird and mammal abundance and diversity, as well as an ecological process (predation); and (2) people's perception responses, such as the importance that people assign to the trees, wildlife and the site. We designed two independent Before‐after‐control‐impact (BACI) experiments based on two sites where tree removals were occurring (impact sites): an urban park and a residential street, both located in the Greater Melbourne Area, Australia. We selected three control sites for each impact site, or four per experiment. Ecological data were collected through field surveys, and social data on people's perceptions through intercept questionnaires among park and street users. Data were analysed using a GLMMs to determine the combined effect of time (before and after) and treatment (impact and controls). At the urban park, the abundance of nectarivorous birds and possums both declined by 62% following tree removal, while invertebrate predation increased by 82.1%. The level of importance people assigned to the urban park and to the trees at the site decreased after tree removal, and people's attitudes towards tree planting became more positive, meaning more people wanted to plant more trees at the site. None of these changes were observed in the street experiment where fewer and smaller trees were removed, suggesting that effects may be highly specific to context, where factors such as tree volume, diversity and arrangement influence the magnitude of social–ecological effects observed. By demonstrating the social–ecological effect of removing urban trees, we provide evidence that urban trees provide critical habitat to urban wildlife and are perceived as an important aspect of the human experience of urban nature. Read the free Plain Language Summary for this article on the Journal blog.

Invertebrates comprise the most diversified animal group on Earth. Due to their long evolutionary history and small size, invertebrates occupy a remarkable range of ecological niches, and play an important role as “ecosystem engineers” by structuring networks of mutualistic and antagonistic ecological interactions in almost all terrestrial ecosystems. Urban forests provide critical ecosystem services to humans, and, as in other systems, invertebrates are central to structuring and maintaining the functioning of urban forests. Identifying the role of invertebrates in urban forests can help elucidate their importance to practitioners and the public, not only to preserve biodiversity in urban environments, but also to make the public aware of their functional importance in maintaining healthy greenspaces. In this review, we examine the multiple functional roles that invertebrates play in urban forests that contribute to ecosystem service provisioning, including pollination, predation, herbivory, seed and microorganism dispersal and organic matter decomposition, but also those that lead to disservices, primarily from a public health perspective, e.g., transmission of invertebrate-borne diseases. We then identify a number of ecological filters that structure urban forest invertebrate communities, such as changes in habitat structure, increased landscape imperviousness, microclimatic changes and pollution. We also discuss the complexity of ways that forest invertebrates respond to urbanisation, including acclimation, local extinction and evolution. Finally, we present management recommendations to support and conserve viable and diverse urban forest invertebrate populations into the future.