Drone surveys cause less disturbance than ground-based surveys in endangered spectacled flying-foxes (Pteropus conspicillatus)

Robust population estimates are critical for detecting biodiversity declines. Thermal drones offer a promising alternative to invasive, imprecise ground-based techniques for monitoring endangered spectacled flying-foxes (Pteropus conspicillatus). This study evaluated spectacled flying-fox behavioural responses to drones to address concerns that they will disturb roosting colonies. At two studied roosts, drones elicited minimal disturbance, whereas ground-based surveys triggered alarm and escape responses, particularly among unhabituated flying-foxes. These findings highlight thermal drones as a non-invasive tool for monitoring spectacled flying-foxes. Further research is needed to evaluate their accuracy and precision compared with ground counts.