Bats show responses to anthropogenic stressors linked to changes in other ecosystem components such as insects, and as K-selected mammals, exhibit fast population declines. This speciose, widespread mammal group shows an impressive trophic diversity and provides key ecosystem services. For these and other reasons, bats might act as suitable bioindicators in many environmental contexts. However, few studies have explicitly tested this potential, and in some cases, stating that bats are useful bioindicators more closely resembles a slogan to support conservation than a well-grounded piece of scientific evidence. Here, we review the available information and highlight the limitations that arise in using bats as bioindicators. Based on the limited number of studies available, the use of bats as bioindicators is highly promising and warrants further investigation in specific contexts such as river quality, urbanisation, farming practices, forestry, bioaccumulation, and climate change. Whether bats may also serve as surrogate taxa remains a controversial yet highly interesting matter. Some limitations to using bats as bioindicators include taxonomical issues, sampling problems, difficulties in associating responses with specific stressors, and geographically biased or delayed responses. Overall, we urge the scientific community to test bat responses to specific stressors in selected ecosystem types and develop research networks to explore the geographic consistency of such responses. The high cost of sampling equipment (ultrasound detectors) is being greatly reduced by technological advances, and the legal obligation to monitor bat populations already existing in many countries such as those in the EU offers an important opportunity to accomplish two objectives (conservation and bioindication) with one action.

Bats are often unfairly depicted as the direct culprit in the current COVID-19 pandemic, yet the real causes of this and other zoonotic spillover events should be sought in the human impact on the environment, including the spread of domestic animals. Here, we discuss bat predation by cats as a phenomenon bringing about zoonotic risks and illustrate cases of observed, suspected or hypothesized pathogen transmission from bats to cats, certainly or likely following predation episodes. In addition to well-known cases of bat rabies, we review other diseases that affect humans and might eventually reach them through cats that prey on bats. We also examine the potential transmission of SARS-CoV-2, the causal agent of COVID-19, from domestic cats to bats, which, although unlikely, might generate a novel wildlife reservoir in these mammals, and identify research and management directions to achieve more effective risk assessment, mitigation or prevention. Overall, not only does bat killing by cats represent a potentially serious threat to biodiversity conservation, but it also bears zoonotic implications that can no longer be neglected.

The replacement of natural areas due to urbanisation represents a major threat to wildlife. Wild species may be classified according to their response towards urban areas. Such responses lead to persistence (exploiters and tolerant) or local extinction (avoiders) of species within cities, which in turn contributes to shaping the assemblages found therein, usually according to specific sets of ecological and morphological traits. Here, we focus on Orthoptera as a model group to test hypotheses on the relationships between species' traits and persistence in urban environments, using the city of Rome, Italy, as study area. By compiling and comparing species checklists for two distinct time frames, we assessed assemblage variation across the last three decades and revealed that local extinction of Orthoptera in urban areas is trait‐biased. Species with low mobility and fertility, and narrower—more specialised—climatic niches showed higher probability of local extinction. Our results point at both climate and land use changes as potentially major drivers of orthopterans' local extinction in urban areas, suggesting that strategies to increase natural habitat preservation and connectivity, and mitigate climate‐change induced events, may both prove effective in sustaining richer insect communities within urban areas.