Thermal ecology of natterjack toads (Bufo calamita) in a semiarid landscape

(1).To monitor the seasonal variation of body temperature (tb) in free-ranging adult Bufo calamita, 15 toads were radio-tracked at Mas de Melons (Catalonia, Spain) using temperature-sensitive transmitters implanted to the abdominal cavity.(2).tb varied between +0.3 °C during winter and 32.2 °C during summer demonstrating behavioural avoidance of ambient temperature extremes by choosing moist and temperature-buffered microhabitats.(3).Frost avoidance included frequent changes of shelter sites by aboveground dispersal, distinguishing this population from conspecifics evading frost by burrowing.(4).The control of water balance superposed behavioural efforts to optimize tb identifying natterjacks as thermal conformers.