Bat Responses to the Modern Nightscape

Author

• Meredith Tatum Goza, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2026

Degree Name

Master of Science

Department

Zoology

First Advisor

Bastille-Rousseau, Guillaume

Abstract

Anthropogenic disturbances are rapidly reshaping both the structural and sensory landscapes that animals experience. For nocturnal species like bats, these changes can affect how individuals perceive and move through their environment. One form of increasingly pervasive anthropogenic disturbance is artificial light at night (ALAN). ALAN can alter animal behavior, yet its effects on sensory systems remain poorly understood. In echolocating bats, changes in call structure may reflect shifts in perceptual demands under altered light conditions at night. Here, I used acoustic data collected across naturally dark and artificially lit sites spanning both edge and cluttered interior habitats to examine how echolocation structure changes in the presence of ALAN. Echolocation responses to ALAN were dependent on habitat type, with bats in cluttered habitats using lower-resolution pulses in the presence of light, whereas bats in edge habitats used higher-resolution pulses in the presence of light. Additionally, different species exhibited a wide range in magnitude of structure changes in the presence of light. ALAN alters sensory behavior in a context-dependent manner, emphasizing the importance of considering both environmental structure and species composition when assessing ecological impacts of light pollution and potential conservation management strategies. The second disturbance analyzed in this work was linear infrastructure, specifically powerline rights-of-way (ROWs). In the United States alone, millions of miles of powerline ROWs create linear landscape features through forests, impacting a wide range of wildlife communities, including bat foraging and commuting behavior. I used a geolocated transect of acoustic recorders to localize bats and track their movements in and through a ROW bisecting a heavily forested area. Straight-line flights parallel to the ROW (commuting flights) were the most common flight patterns among all species, especially earlier in the night. Crossing flights, perpendicular to the ROW were most common among clutter-adapted species, and later in the night for more open-adapted species. Flight patterns consistent with foraging (erratic) were used mostly on darker nights with similar occurrences among species. Overall, highly adaptable, open-space foragers make heaviest use of ROWs while clutter-adapted species avoid spending long periods in them, especially under bright moonlight. Anthropogenic changes to the landscape tend to create winners and losers by increasing foraging and commuting habitats for adaptable species while decreasing them for specialists. Conservation decisions about bats around powerline ROWs must account for nuances in use by different species in different scenarios.