Category Archives: Research News

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.

Download this publication.

The Powers lab has purchased a FLIR SC6700 infrared (IR) camera.  The camera is the first piece of equipment purchased with NASA-grant funding.  The SC6700 is a high-speed high-resolution camera built using the best technology available.  For the NASA project the SC6700 will be used to track nighttime changes in body-surface temperature to monitor frequency and duration of torpor use.  The lab also plans to use the SC6700 this spring to study body-temperature effects on female attractiveness in red-sided garter snakes.

The lab was first introduced to IR cameras two years ago during our work with Dr. Bret Tobalske at the University of Montana.  Over the past two years the lab has conducted a study in which we examined heat dissipation during hovering and forward flight in hummingbirds (see image below).  The bulk of these data were gathered as part of Kyle Maki’s project.

Paige holding a red-sided garter snake

Several members of the Powers lab will once again travel to the Society for Integrative and Comparative Biology meeting to be held in Charleston, SC January 3-7.  Paige Copenhaver will present two posters.  The first will cover our data on the energetic cost of copulatory plug production in small vs. large male red-sided garter snakes  (Thamnophis sirtalis parietals) and the second thermal tolerances in free-living rough-skinned news (Taricha granulosa).  Paige will be the first research student ever in my lab to present two studies in a single meeting.

Kyle collection DPIV data

Also Kyle Maki will present our study on heat dissipation during flight in Calliope hummingbirds (Stellula calliope).  In this study we identify the major regions of heat dissipation from body surfaces during flight using high-quality infrared video imaging.

Finally, I will be presenting an oral paper on the energetic cost of reproduction in male vs. female red-sided garter snakes.  This will actually be the first paper I have presented on reptiles and represents the culmination of 4+ years of work.

Hummingbird Feeding in the Respiratory Mask

The Powers lab joined a team of scientists headed by Dr. Catherine Graham (SUNY Stonybrook) in submitting a grant proposal to NASA to study how hummingbird populations respond to climate change.  It was recently announced that the grant, which was for $1.4 million, was going to be funded.  The Powers lab will receive approximately $250K ($60K of which are matching equipment funds from GFU) over four years which will be used for physiological studies in North American, Mexico, and South America.  Funds from the grant will be used to purchase equipment, pay for travel, and support several students.  To read the complete press release from George Fox University click here.