Lab Presents NASA-Project Data at SICB in Austin, TX!

IMG_1791The entire lab packed up their data and traveled to the SICB meeting in Austin, TX January 3-7.  The big day for the lab was Monday, January 6 when Don Powers gave a talk in the morning entitled “Physiological Sensitivity of Hummingbirds to Warming Environmental Temperatures” where he summarized data from this past summer.  Later that afternoon all the students present posters in which specific projects were covered in greater depth.  Specific posters presented were:

Influence of Environmental Temperature on Heat Dissipation in Hummingbirds (Katie Langland)

Is the Use of Torpor by Hummingbirds Limited in Landscapes with Warm Nighttime Temperatures? (Rebecca Schroeder)

Assessing Effects of Temperature on Daily Energy Expenditure in Hummingbirds Using a Non-Invasive Doubly Labeled Water Protocol (Joseph Canepa)

Using an Endotherm Energetic Model to Predict Hovering Metabolic Rate in Hummingbirds (Sean Powers)

All the students did really well at the meeting.  One poster judge who judged Becca’s poster went out of his way to tell us how exceptionally well Becca did presenting her data.  This is not surprising.  Even though the lab is staffed only with undergraduates, our students routinely engage meeting attendees with a solid understanding of the science associated with their projects.

New Students Join the Powers Lab!

SNSara Nutter, junior biology major , joined the lab this spring.  Sara is interested in both field sciences and science writing and will continue infrared (IR) thermography studies in southeastern Arizona started by Katie Langland the last two years.  This year Sara will extend the IR work to high-elevation sites in an effort to increase our understanding of hummingbird tolerance of high environmental temperature.  Sara’s work, along with other projects she will contribute to, is part of the lab’s NASA-funded work on how hummingbirds might respond to climate change.  Sara’s work this summer will be funded by a George Fox University (GFU) Richter Scholar Grant.

IMG_1719Noemi (“Mimi”) Camacho, sophomore biology major, will also be joining the lab this spring.  While Mimi is interested in a career as a health professional she feels developing her basic science skills is complimentary to her professional goals.  Mimi’s core project will be mapping the thermal profile of our focal landscapes in southeastern Arizona.  This work, along with other projects Mimi will be involved in, is critical to the lab’s assessment of how hummingbirds might respond to climate change.  Mimi’s work this summer will be funded by a George Fox University (GFU) Richter Scholar Grant.

Hummingbird Response to Climate Change in Southeastern Arizona: Field Season 2013!

IMG_2459When school was over last spring the lab hardly had time to breath before we packed up and headed off to southeastern Arizona to start our first full season of data collection associated with the NASA project.  Actually, I (Don) was the first to leave since I am too old to power through a drive from the north to the south end of the country in less than three days.  Katie, Becca, and Joey on the other hand pretty much made it to Arizona at the same time I did but in one less day.  We landed in Patagonia, AZ which would be our base of operations for the summer.  This location is not only central to the landscapes we would work on this year but also near where friend and project collaborator Dr. Susan Wethington (Hummingbird Monitoring Network) lives.

IMG_2520The first week of of the field season was intense training to get everyone up to speed on applying what we had learned in the lab to an actual field setting.  After that the next couple weeks were split between kicking off our work and supporting a collaborative project with Dr. Bret Tobalske (University of Montana).  The collaborative work was an extension of heat-balance work on calliope hummingbirds that we have been doing at Bret’s lab in Montana.  Here in Arizona we added larger size hummingbirds to the mix in the hope of looking at how size might influence various aspects of hovering.

IMG_2952For the balance of the summer our team focused on four key experiments designed to assess the physiological response of hummingbirds to temperature in the field: 1) Thermal profiling of two distinct landscapes, 2) measurement of daily energy expenditure using a modified version of the doubly-labeled water (DLW) technique, 3) assessment of a hummingbird’s thermal load across a broad temperature range using infrared thermography, and 4) assessment of differences in torpor use by hummingbirds that live in different temperature regimes.  We spent a total of 2.5 months in Arizona completing these experiments returning to Newberg on July 18.  The students did a marvelous job.  They worked hard and never complained about the sometimes long days.  Over the next several weeks we will be frantically crunching numbers in preparation for submitting abstracts for the January SICB meeting in Austin, TX.  The deadline is August 26 (YIKES!).





















2013 Field Season Kicks Off With SE Arizona Workshop!

Research planning session at El Coronado.

Research planning session at El Coronado.

This year’s field season officially got underway with a week long workshop in southeastern Arizona. The purpose of the workshop was for the PIs of the hummingbird climate change project to select specific Arizona landscapes to be studied and to agree on questions to be addressed this coming summer. Additionally several interns from various parts of South America who will be working on the project this summer attended the workshop and were introduced to a variety of protocols for assessing nectar resources and measuring hummingbird energetics.

Weighing a hummingbird on our new Sartorius balance!

Weighing a hummingbird on our new Sartorius balance!

The Powers lab used this time to try out a revision of the non-invasive hummingbird doubly labeled water (DLW) protocol. The specific revision involves changing how we measure the initial dose size of isotopic water. To make this method totally non-invasive hummingbirds are dosed by feeding them nectar made with isotopically enriched water. Last summer dose size was calculated by weighing a syringe feeder before and after feeding the hummingbirds. This proved to be problematic as the syringe would occasionally drip creating large errors in our measured dose size. This year we have switched to measuring the bird before and after feeding. Additionally, we have purchased a more precise scale which should also improve the accuracy of our measurements.

The DLW sessions done during the workshop were highly successful! Between the two sessions (El Coronado Ranch and the Santa Rita Experimental Range) we labeled a total of 78 hummingbirds and recaptured 29. Our 37% recapture rate would be the envy of most doing DLW studies!

SICB Meeting 2013!

The lab packed up some of our results from this past year’s research and headed off to the SICB meeting in San Francisco to share them with national and international colleagues from across the globe.  Our work attracted a great deal of attention this year and the students did a wonderful job of exciting our colleagues about what we have been doing.


The first full day of the meeting was action packed!  The morning started with a special symposium in honor of the lifetime work of Ken Nagy (pictured), who in the 1970’s developed protocols for using the doubly-labeled water (DLW) technique to measure energy expenditure by animals in the field.  This method revolutionized our understanding of how animals cope with their environments in a variety of circumstances.  When Don Powers was a Master’s student at San Diego State in the early 1980’s he had the pleasure of doing a short project with Ken using DLW to measure daily energy costs in Anna’s hummingbirds (Calypte anna).  This project resulted in Don’s second publication.

DPIV-ImageNext up Don Powers gave a talk entitled “Metabolic Power, Mechanical Efficiency, and Heat Production during Hovering and Forward Flight in Calliope Hummingbirds (Selasphorus calliope).” In his talk Don summarized the results of the work he and Bret Tobalske (University of Montana), along with several current and former research students, have been doing the past several years on maintenance of heat balance in hummingbirds during hovering and forward flight.  The picture on the left is an example of a Digital Particle Image Velocimetry (DPIV) image taken of one of our hummingbirds in flight.  DPIV was the method we used to calculate the amount of metabolic power that was used to run the hummingbird’s flight muscles.

IMG_0838That evening research student Luke Andrew presented his poster entitled “Use of Torpor by a High- and Mid-Elevation Hummingbird Species in Southeastern Arizona.”  The poster summarized data collected this past summer in collaboration with Dr. Susan Wethington of the Hummingbird Monitoring Network on patterns of torpor (nighttime hypothermia) use in broad-tailed (Selasphorus platycerus) and broad-billed (Cynanthus latirostris) hummingbirds.  Even though they put Luke back in a dark corner of the exhibit hall he had good traffic including some well known physiologists.

IMG_1258The lab’s final two poster presentations occurred on Sunday.  Research student Katie Langland presented her study entitled “Use of Infrared Thermography to Measure Body-Surface Heat Dissipation in Free-Living Hummingbirds.”  In this study, also done in collaboration with Dr. Susan Wethington, Katie explored the relationship between environmental temperature and surface heat loss in hummingbirds.  Katie had a busy night as there steady stream of attendees interested in what she had to say.

IMG_1256Finally, former research student and current adjunct instructor in the Biology Department Sean Powers agreed to help the lab out by analyzing some infrared thermography data and presented a poster entitled “The Importance of Female Temperature in the Attraction of Courting Males in Red-Sided Garter Snakes (Thamnophis sirtalis parietalis).”  Sean’s data cast doubt on a long-standing hypothesis that males are more attracted to cold females.  The basis of this hypothesis is that when females emerge from the den they are cold and likely to be unmated.

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