How Does Artificial Light at Night Affect Fruit Bat Activity and Foraging Behaviour in Urban Areas?

Artificial light at night (ALAN) is now one of the most visible features of urbanization, yet its effects on nocturnal animals remain unevenly understood. This paper examines how streetlight intensity may affect fruit bat activity and foraging behaviour in urban areas, with special attention to Indian flying foxes (Pteropus medius) and other pteropodid fruit bats. Because fruit bats are primarily frugivorous or nectarivorous, the term “hunting behaviour” is treated here as foraging behaviour: the search for fruit, flowers, nectar, and feeding trees. The central research question is whether bat sightings, feeding visits, or acoustic/social-call activity decrease as light intensity increases. A review of ecological-light-pollution literature suggests that ALAN can alter nocturnal activity by changing visual conditions, perceived predation risk, emergence timing, commuting routes, and access to fruiting resources. Evidence is strongest for insectivorous bats, but experimental work on frugivorous bats also shows that illumination can reduce fruit harvesting and seed dispersal (Lewanzik & Voigt, 2014). Indian urban studies show that fruiting tree availability and tree cover strongly influence Indian flying fox foraging sites (Roy et al., 2024), making light intensity one part of a larger urban-habitat filter. The paper proposes a field design comparing dark control, low-light, medium-light, and high-light sites while controlling for tree cover, fruit availability, moon phase, weather, and traffic. The expected pattern is a negative association between lux level and bat activity, especially near exposed fruiting trees and commuting paths. The paper concludes that wildlife-sensitive lighting should reduce unnecessary lux, shield lamps downward, preserve dark corridors, retain fruiting native trees, and treat darkness as an ecological resource rather than an absence of infrastructure.