Meeting Abstract

32-5  Saturday, Jan. 4 14:30 – 14:45  Air Temperature Limits Metabolic Scope in Mid-elevation Tropical Birds OLIVER, KD*; MARTIN, TE; WOLF, BO; University of New Mexico; University of Montana; University of New Mexico; University of New Mexico; University of New Mexico kristenoliver@unm.edu

As global air temperatures continue to rise due to climate change, the effects of temperature on the breeding performance of birds is of increasing interest. If the ability to dissipate heat generated by activities such as foraging and feeding nestlings is diminished in future climates then reproductive success may decrease. With this question in mind, we surveyed a tropical mid-elevation (1500-1900m) bird community in Mount Kinabalu National Park in Borneo, Malaysia where air temperatures range from 15-21^oC. We used a hop-flutter flight wheel and flow-through respirometry to measure resting metabolic rate, exercise metabolic rates, evaporative water loss, and body temperature in 24 species of birds ranging in size from 6g to 140g in dry air over a range of air temperatures (16^oC – 30^oC). Under dry conditions, metabolic scope (peak metabolic rate – resting metabolic rate) and exercise performance were highly diminished at T_air > 28^oC suggesting that warmer temperatures may importantly limit activity and potentially breeding performance under future climates.