Climate change impacts for desert birds High temperature and thermoregulation in non-passerine desert granivores


Meeting Abstract

113.2  Tuesday, Jan. 7 10:45  Climate change impacts for desert birds: High temperature and thermoregulation in non-passerine desert granivores SMITH, E.K.*; O’NEILL, J.; WOLF, B.O.; University of New Mexico ericksmith2@yahoo.com

During the summers of 2012 and 2013 we captured White-winged Doves (WWDO) and Gambel’s Quail (GAQU) near Tucson, AZ, USA. Using flow-through respirometry we measured the effects of air temperature on evaporative water loss, resting metabolic rate, body temperature, and evaporative efficiency. Both species are obligate drinkers and our goals were to establish values for critical thermal max and estimate performance in a hotter climate. We found that WWDO maintained very low resting metabolic rates and relatively low body temperatures over a wide range of air temperatures (40 – 64°C). GAQU, in contrast, were much more sensitive to increasing air temperature, experiencing spikes in resting metabolism and rapid hyperthermia as air temperatures approached 52°C. Both species are common breeders in the Sonoran desert during the hot summer, however, WWDO evaporate water at a 40% higher rate at 50°C than GAQU. Their higher rates of evaporation and lower resting metabolism makes WWDO more efficient at heat dissipation, enabling them to tolerate temperatures as high as 64°C (147°F) while maintaining body temperatures at or below 45°C.

the Society for
Integrative &
Comparative
Biology