Аннотация:This study examines the ecophysiological responses of common waxbills to temperature variation in Portugal. We measured body condition and basal metabolic rate (BMR) during summer and winter across two regions in Portugal. Body condition was negatively correlated with temperature, while the relationship between BMR and temperature varied seasonally. In summer, BMR decreased with increasing temperature, but in winter, it remained low and stable, indicating physiological adjustments to seasonal changes.