An Aerial Approach to Investigating the Relationship between Macromoths and Artificial Nighttime Lights Across an Urban Landscape1

Abstract Urbanization represents a dramatic type of habitat change. Not only does it remove natural habitat for ecological communities, it also increases artificial nighttime light levels that can have negative impacts on night-flying species, such as moths. Feeding, mating and oviposition behaviors of moths can be affected by artificial nighttime lights, and they become more exposed to predators such as bats. In this study, an aerial approach was used to measure the prevalence of artificial nighttime light across an urban landscape (East Lansing, Michigan, USA). These light levels were related to macromoth species richness and abundance at 32 urban trapping sites. Both moth species richness and abundance were positively related to vegetation cover across the landscape, but there was no consistent, discernible impact of artificial nighttime light on either variable. This may be due to the lower attractiveness of high-pressure sodium lights that are used across this particular urban landscape, or to a negative association between the prevalence of landscape light levels and the amount of landscape vegetation. There is also a possibility that macromoths in urban areas have adapted to be less sensitive to light. This study is one of the first to use an aerial approach to measuring urban nighttime lights and departs from the most commonly held theory that increased light prevalence is associated with a depauperate moth assemblage.