A study on respiratory evaporative water loss during forward and hover flight in hummingbirds has been published in the journal Comparative Biochemistry and 
Physiology, Part A. The study which was conducted both at field sites in Arizona and in the laboratory at the University of Portland describes the impact of respiratory evaporation on overall water balance during flight and the role it plays in thermoregulation. This study is particularly interesting because hummingbirds are among the smallest of endothermic vertebrates and as such have extremely high metabolic rates. High metabolic rates generally trend towards substantial respiratory evaporative water loss (REWL) which could severely hinder these bird’s ability to maintain water balance. However, because hummingbirds have an unusually high rate of water intake due to their nectar diet REWL has an unusually low impact on the hummingbird’s water budget.
Phil Getsinger
Phil Getsinger and Sean Powers, former students in the Powers lab,
played prominent roles in collecting the data for this project and are coauthors on the paper. This study also involved a primary collaborator with the Powers lab, Bret Tobalske, who at the time of data collection was at the University of Portland and is not at the University of Montana.
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