Welcome to the American Ornithological Society 2018 Annual Conference. We are pleased to have you join us at the lovely Hilton El Conquistador Resort in Tucson, AZ.
Reproduction is known to be one of the most metabolically intense periods of the annual cycle for birds. For species that live in hot deserts and breed during the spring and summer, daily activity cycles may be constrained by high air temperatures. Animals that are active in the heat may be limited in the types of activities that they can undertake and these activities may have effects on adult body condition or alternately nest attendance rates and fitness. We used a simple heat transfer model and thermoregulatory data on 14 species of Sonoran Desert birds to examine how maximum workloads are limited by environmental temperature. We found that doves and nightjars had the highest available metabolic scope associated with their low metabolic rates, high rates of water loss and use of hyperthermia to minimize heat loads and water loss rates. Songbirds and owls have lower metabolic scopes and a more limited ability to work in the heat indicating that their breeding activities may be more constrained by a warming climate. These observations suggest strong shifts in breeding cycles and higher nest failure rates for some species.
