CURRENT STUDENT RESEARCHERS
Katie returns to the lab for a second year and will continue her work with the lab’s new FLIR SC6700 IR camera. She will focus on protocols designed to assess thermal load in hummingbirds using infrared thermography. Data Katie gathers will be helpful in determining how hummingbirds respond to the increasing temperatures associated with climate change (the core purpose of the lab’s NASA grant). In addition to our hummingbird work last year Katie studied the role female body temperature plays in the courtship decisions of male red-sided garter snakes (Thamnophis sirtalis parietals) in order to work out our IR thermography protocols. She presented her work at the Society for Integrative and Comparative Biology Meeting in San Francisco, CA. Click here to view the poster Katie presented at SICB 2013.
Rebecca (“Becca”) joined the lab as a sophomore biology major this past year and is the lab’s first student research scholar supported by the NASA grant. Her core project was a study of the differential use of torpor (nighttime hypothermia) across different thermal landscapes. Data gathered by Becca will provide important information about how hummingbirds alter energy-management strategies in different thermal regimes. Information on energy management is critical as we consider the potential consequences of warming temperatures associated with climate change. One of the key things that Becca brings to the lab is FUN! She never takes things too seriously (except when the lab computer is not behaving) and always tries to keep our moods light.
Joey joined the lab this past year as a sophomore biology major and is supported by a Richter Science Scholar Grant from the University. His core project was to help develop a noninvasive technique for measuring daily energy expenditure in free-living hummingbirds. The work centered primarily on modification of the doubly-labeled water (DLW) technique in which CO2 production (a measure of metabolic rate) is estimated by measuring the turnover rate of stable (non-radioactive) isotopes introduced into an animal’s body. Joey helped design a protocol in which the hummingbirds were dosed by feeding them isotopically enriched nectar. Joey loves to play the drums and will turn anything solid into a percussion instrument.
PAST STUDENT RESEARCHERS
This year Luke will be involved in multiple projects related to the lab’s NASA funded study entitled “Combining Remote-Sensing and Biological Data to Predict the Consequences of Climate Change on Hummingbird Diversity.” Luke’s primary focus will be to help develop protocols for using the doubly-labeled water (DLW) method to measure field metabolic rate (energy expenditure) in potentially remote field sites in Arizona, Mexico, and South America. The DLW method uses the turnover rate of stable isotopes in body water to estimate the rate of CO2 production (a measure of metabolic rate) and body-water turnover rate. Luke will measure isotopic turnover using an LGR Water Isotope Analyzer recently ordered by the lab. In addition to the DLW studies Luke will be involved in measurements of hovering metabolic rate in free-living birds using open-flow respirometry for both the NASA project and the lab’s continuing collaboration with Dr. Bret Tobalske at the University of Montana.
For the past several years the lab has been studying the role aquaporin (AQP) water channels play in regulation water transport across the ventral skin of rough-skinned newts (Taricha granulosa), and how the localized distribution of AQPs changes when the newts become acclimated to either a terrestrial or aquatic existence. Elliott will continue this work during the coming year conduction experiments where he will attempt to identify the initial steps of the cellular signaling pathways involved in regulation of AQPs 1-4. In addition Elliott will conduct experiments using stable isotopes designed to measure actual water transport across the ventral skin to verify that previously observed changes in AQP distribution in the terrestrial vs. aquatic condition indeed alter skin permeability. Finally, the lab has obtained some exclusively terrestrial Plethodontid salamanders (Plethodon shermani) that will allow Elliott to compare AQP distribution and localization in a terrestrial model to the more aquatic newts.
Kyle will be studying the effect of unpredictable wind currents on hovering energetics in Calliope hummingbirds. In addition she will use cutting-edge thermal imaging technology to study heat dissipation from body surfaces during hummingbird flight. Both these studies will be conducted in the lab of Dr. Bret Tobalske at the University of Montana.
Most students in the Powers Lab are funded by grants by the Richter Scholar Program at George Fox University.
This summer Ryan will be refining the immunofluorescence (IF) techniques he developed last summer to track localized expression of aquaporin 1, 2, and 4(AQP1,AQP2, and AQP4) in rough-skinned newt (Taricha granulosa) tissues. This Summer Ryan will also repeat experiments using antibodies for AQPe. In addition he will use Western blotting to isolate and quantify AQP proteins in newts that are acclimatized to both terrestrial and aquatic conditions. In addition to the molecular studies Ryan will characterize AQP expression and localization in newts subject to dehydration. Finally, time permitting Ryan will begin experiments designed to identify cellular signaling mechanisms that regulate skin AQPs.
Paige will be working on the energetic cost of copulatory plug production in large vs. small male red-sided garter snakes (Thamnophis sirtalis parietals). She did the lions share of the work designing a hybrid system for measuring oxygen consumption that employees both open and closed-system respirometry techniques. In addition to working on garter snakes Paige also completed a study on thermal preferences in rough-skinned newts (Taricha granulosa) in a natural environment. In support of this latter study Paige will soon perform a Y-maze study in the lab to test thermal preference under controlled conditions.