Flying Thermometers: How Urban-Dwelling Bats Help Map Urban Heat Islands

This study introduces a novel approach to reconstruct Urban Heat Islands (UHI) by leveraging urban-dwelling bats as biologically-assisted samplers (BAS), offering a unique perspective similar to urban residents. Using Egyptian fruit bats equipped with temperature loggers, we mapped spatial air temperature (Tair) profiles across diverse urban environments. To evaluate the feasibility of this method, we employed mixed-effects models and Geographically Weighted Regression (GWR) to analyze the influence of urban features on Tair distribution. Vegetation emerged as a critical factor in mitigating urban heat, with winter Tair differences of 2–5 °C observed between dense urban areas and adjacent vegetative or open spaces. A prominent UHI hotspot was identified in winter over the Ayalon highway, while differences were less pronounced during summer nights due to coastal cooling from sea breezes. Preliminary results further reveal a unique 3D perspective of UHI: Tair variations above dense urban areas were smaller compared to vegetative zones.

This approach demonstrates that urban bats, as local "residents," can act as efficient agents for atmospheric monitoring, complementing low-cost citizen science initiatives to gather environmental data. However, challenges associated with crowdsourced data collection, such as ensuring data accuracy, coverage, and integration with bat-derived scans, highlight the need for robust data validation frameworks. Despite these challenges, the synergy between bats and citizen science offers valuable insights into local vulnerabilities and informs targeted mitigation strategies, particularly during nocturnal hours when UHI effects are most pronounced.