Differential Flight Responses of Sympatric Raptor Species to Weather Conditions and Extreme Temperature Events

Climate change has increased the frequency, severity, and duration of extreme weather events, for example, heatwaves, underscoring the need to comprehend their impact on animal behavior. Flying organisms, particularly birds, are greatly affected by changes in atmospheric conditions and may modify their speed or direction, adjust their flight strategy, and even make decisions on whether to fly based on weather. In this study, we assessed flight-related parameters in three GPS-tagged raptor species: the golden eagle (<i>Aquila chrysaetos</i>), the Bonelli's eagle (<i>Aquila fasciata</i>), and the Spanish eagle (<i>Aquila adalberti</i>), in relation to weather conditions and heatwaves. The results showed that the three species varied in their flight patterns despite similar environmental conditions, including temperature, precipitation, wind speed, and atmospheric pressure. Each species exhibited unique strategies and responsiveness to heatwaves, reflecting diverse adaptive capacities and behavioral flexibilities. Specifically, Bonelli's eagle displayed comparatively minor adjustments in its flight strategy during periods of extreme temperature, contrasting with the pronounced behavioral variations observed in the golden eagle. These findings suggest that extreme and unpredictable weather events, particularly heatwaves, may impact raptor species differently. An understanding of how extreme weather events may impact individual fitness, through modifications to energy expenditure and foraging practices, is essential for predicting their potential impact on long-term population dynamics.