Airport noise disturbs foraging behavior of Japanese pipistrelle bats

The expansion of anthropogenic noise poses an emerging threat to the survival and reproductive success of various organisms. Previous investigations have focused on the detrimental effects of anthropogenic noise on the foraging behavior in some terrestrial and aquatic animals. Nevertheless, the role of airport noise in impairing foraging activities of most wild animals has been neglected. Here, we aimed to assess whether foraging behavior in free‐living Japanese pipistrelle bats (Pipistrellus abramus) can be disturbed by airport noise. We used audio recording to monitor foraging activities of bats at 11 sites around the runway of a municipal airport. We quantified noise level and spectra, aircraft activity, habitat type, nightly temperature, wind speed, and moon phase for each site. The analysis revealed that noise level and aircraft activity were significant negative predictors for the number of bat passes and feeding buzzes around the runway, even after controlling for the effects of other environmental factors. There was no marked spectral overlap between bat echolocation pulses and airport noise in the presence and absence of low‐flying aircraft. The spectro‐temporal parameters of echolocation vocalizations emitted by bats were dependent on noise level, aircraft activity, and habitat type. These results provide correlative evidence that airport noise can reduce foraging activities of wild pipistrelle bats. Our findings add to the current knowledge of adverse impacts of airport noise on foraging bats in artificial ecosystems and provide a basis for further research on the mechanisms behind noise pollution near airports.

Anthropogenic noise affects insect and arachnid behavior, thus changing interactions within and between species

Urbanization and the by-product pollutants of anthropogenic activity pose unique threats to arthropods by altering their sensory environments. Sounds generated by human activities, like construction and road traffic, can oversaturate or interfere with biotic acoustic cues that regulate important ecological processes, such as trophic interactions and the coordination of mating. Here, we review recent work exploring how anthropogenic noise impacts inter-intra-specific interactions in insects and arachnids. We outline empirical frameworks for future research that integrate three mechanisms by which anthropogenic noise alters behavior through interference with acoustic cues: masking, distraction, and misleading. Additionally, we emphasize the need for experimental designs that more accurately replicate natural soundscapes. We encourage future investigations on the effects of developmental exposure to noise pollution and the impacts of multiple interacting sensory pollutants on insect and arachnid behavior.

What do we know (and need to know) about the role of urban habitats as ecological traps? Systematic review and meta-analysis

Urban areas represent a spectrum that goes from being safe habitats for biodiversity (i.e., habitats more or equally preferred, without costs to fitness) to being ecological traps (i.e., habitats more or equally preferred, but with costs to fitness). Given the imminent urban expansion, it is valuable to assess how biodiversity is responding to urbanization and thus generate timely conservation strategies. We systematically review the urban ecology literature to analyze how much do we know about the role of urban areas as ecological traps. Using a formal meta-analytical approach, we test whether urban areas are functioning as ecological traps or as safe habitats for different taxonomic groups. We generated a data set of 646 effect sizes of different measures of habitat preferences and fitness from 38 papers published between 1985 and 2020. The data set covered 15 countries and 47 urban areas from four continents, including 29 animal species. Studies from North America and Europe were best represented, and birds were the most studied taxa. Overall, the meta-analysis suggests that urbanized habitats are functioning more as safe sites than as ecological traps, mainly for certain species with characteristics that have allowed them to adapt well to urban areas. That is, many of the studied species prefer more urbanized habitats over other less urbanized sites, and their fitness is not modified, or it is even increased. However, there was high heterogeneity among studies. We also performed meta-regressions to identify variables accounting for this heterogeneity across studies and we demonstrate that outcomes may depend on methodological aspects of studies, such as study design or the approach used to measure habitat preference and fitness. More research is needed for poorly studied regions and on a wider range of species before generalizations can be made on the role of urban areas for biodiversity conservation.

Have artificial lighting and noise pollution caused zoonosis and the COVID-19 pandemic? A review

Where did the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) come from? Did it spread to 'patient zero' through proactive human-animal contact? Why did humans faced an increasing number of zoonotic diseases in the past few decades? In this article, we propose a new theory by which human pollution such as artificial lighting and noise accentuate pathogen shedding from bats and other wild habitants in urban environments. This theory differs from the current hypothesis that wildlife trades and bushmeat consumption largely contribute to the spillover of zoonotic pathogens to humans. As natural reservoirs, bats harbor the greatest number of zoonotic viruses among all mammalian orders, while they also have a unique immune system to maintain functioning. Some bat species roost in proximity with human settlements, including urban communities and surrounding areas that are potentially most impacted by anthropogenic activities. We review the behavioral changes of wild habitants, including bats and other species, caused by environmental pollution such as artificial lighting and noise pollution, with focus on the spillover of zoonotic pathogens to humans. We found that there is a strong positive correlation between environmental stress and the behavior and health conditions of wild species, including bats. Specifically, artificial lighting attracts insectivorous bats to congregate around streetlights, resulting in changes in their diets and improved likelihood of close contact with humans and animals. Moreover, many bat species avoid lit areas by expending more energies on commuting and foraging. Noise pollution has similar effects on bat behavior. Bats exposed to chronic noise pollution have weakened immune functions, increased viral shedding, and declined immunity during pregnancy, lactation, and vulnerable periods due to noised-induced stress. Other wild species exposed to artificial lighting and noise pollution also show stress-induced behaviors and deteriorated health. Overall, evidence supports our hypothesis that artificial lighting and noise pollution have been overlooked as long-term contributors to the spillover of zoonotic pathogens to humans in urban environments.

Why conservation biology can benefit from sensory ecology

Global expansion of human activities is associated with the introduction of novel stimuli, such as anthropogenic noise, artificial lights and chemical agents. Progress in documenting the ecological effects of sensory pollutants is weakened by sparse knowledge of the mechanisms underlying these effects. This severely limits our capacity to devise mitigation measures. Here, we integrate knowledge of animal sensory ecology, physiology and life history to articulate three perceptual mechanisms-masking, distracting and misleading-that clearly explain how and why anthropogenic sensory pollutants impact organisms. We then link these three mechanisms to ecological consequences and discuss their implications for conservation. We argue that this framework can reveal the presence of 'sensory danger zones', hotspots of conservation concern where sensory pollutants overlap in space and time with an organism's activity, and foster development of strategic interventions to mitigate the impact of sensory pollutants. Future research that applies this framework will provide critical insight to preserve the natural sensory world.