Microclimatic drivers of thermoregulatory behaviour in Spectacled Flying Foxes
Date:
Abstract - Climate change is exerting profound impacts on biodiversity, but these effects are often mediated by physiological constraints that influence the ecological and demographic performance of species. To predict and anticipate emerging threats, it is critical to understand the environmental drivers that trigger physiological stress responses in vulnerable species. In this study, we investigated the thermoregulatory behaviour of the Spectacled Flying Fox (Pteropus conspicillatus), a species increasingly affected by extreme heat events. Through focused behavioural observations, we tracked individual flying foxes’ thermoregulatory behaviour in their daytime roosts while simultaneously recording key microclimatic variables, including air temperature, wind speed, humidity, and metrics of solar radiation intensity and exposure. Our analyses reveal that while ambient temperature is a strong predictor of thermoregulatory activity, it only partially explains the escalation to high-cost behaviours such as active fanning. Instead, intense solar radiation emerged as a pivotal factor, interacting with temperature to drive behavioural transitions. These results highlight that physiological stress in spectacled flying foxes —and therefore their vulnerability to heatwaves—is governed by a complex interplay of microclimatic conditions, rather than temperature alone. Understanding these mechanisms is essential to improving predictions of climate change impacts and informing conservation strategies for vulnerable species.