Category Archives: Research News

Don traveled to the University of Montana to some quick experiments with friend and collaborator Dr. Bret Tobalske. For the first time they will be working solely with Eurasian collared doves to 1) begin expansion of their heat dissipation during flight work to non-hummingbirds, and 2) test whether or not gluing thermal pit tags to the skin over the flight muscles is an effective way to measure skin surface temperature beneth the breast plumage. The doves were also large enough that they could insert a thermal pit tag into the dove’s abdominal cavity to measure core body temperature. The goal will be to simultaneously measure core body temperature and skin surface temperature above the flight muscles using the thermal pit tags, and breast plumage surface temperature over the flight muscles using infrared thermography. Measurements were made both for flight and perching. The goal is to gain a better understanding of how rapidly core body heat moves across the plumage for dissipation into the environment.

The entire lab traveled to Phoenix, AZ for the Society for Integrative and Comparative Biology meeting January 3-7. This was an exciting time for all of us not having attended an in-person meeting in two years. Audrey, Tiffany, Whitney, and Emily all presented posters on their Anna’s hummingbird projects attracting a wonderfully high level of interest. Don gave an oral presentation on some of the lab’s more recent work on post-flight dissipation of heat accumulated during hovering drawing on data from both our calliope hummingbird work in Montana and Audrey’s work on Anna’s this past Summer. All-in-all it was a great week of immersion in comparative physiology. Looking forward to next year in Austin, TX!!

Today and tomorrow Audrey Smith and I will be attending the Murdock Collaborative Research Conference. This conference is specifically for undergraduate researchers at small liberal arts universities and is sponsored by the Murdock Charitable Trust. This is a pretty amazing meeting that gives undergraduates doing research the chance to shine. Pre-Covid there would be more than 500 attendees from 36 institutions in the the northwest. Attendance was intentionally reduced this year because of Covid (it was totally virtual last year), but the fact that it is live and in person this year is a win.

Audrey Smith kicked off the program this year with her talk on “Use of the Bill as a Heat Radiator by Anna’s Hummingbird, Calypte Anna.” She did an amazing job making all of us in the lab proud! Sadly Audrey was the only student from the Powers Lab to get to attend the meeting as they limited us to 10 attendees thanks to Covid. It would have been great to have Tiffany, Whitney, and Emily here as well. Regardless, all the George Fox students who did make it to the meeting did extremely well which is a testament to the quality of our program and the scholars that mentor our undergraduates in research.

Well, this past summer did not go as planned. While we did have a couple projects planned for the George Fox University campus much of what we intended to do would be in the Chiricahua Mts in SE Arizona. You know what they say about the best laid plans. When the American Museum of Natural History decided to close the Southwestern Research Station for the year it sent labs across the country scrambling….including ours. Now, our field season had to shift focus to our small population of Anna’s hummingbirds on the GFU campus and my backyard.

What was intended to be two projects on the GFU campus turned in to five. Our biggest challenge was figuring out how to share a limited number of birds, and to pivot a bit on a couple of the projects so everyone could get their work done. Dr. Anusha Shankar, a Rose Postdoctoral Fellow in the Laboratory of Ornithology at Cornell spent the entire summer with us shifting her torpor genomics project to Anna’s. She and Emily Blackwell teamed for the summer building a lab for nighttime torpor work in the shed outside the Powers home. This allowed all the equipment to be under a roof while the bird was outside subject to natural light and temperature. Emily had to change her protocol substantially in order to share birds with Anusha, but when all was said and done both got great results. One highlight of Anusha and Emily’s work was our first use of thermal windows built in to a metabolism chamber that allowed concurrent measurement of surface temperature and metabolic rate. Data from the work will allow us to show that hummingbird surface temperature during the night is a reliable indicator of metabolic state.

Tiffany Regier and Whitney Dobbyn spent the summer tracking thermoregulatory strategies in free-living Anna’s hummingbirds both on the GFU campus and at the Powers home. Tiffany was originally going to do her work in Arizona, but for the second straight year got bit by Covid restrictions and had to settle for work at home. One nice thing about doing the work at GFU is that we had some remarkably hot days allowing us to see if what we were seeing in the laboratory applied to free living birds as well. On key thing that came out of Tiffany and Whitney’s work was how complex and difficult it is to measure radiative heat gains and losses in birds. This is particularly true for flying birds where radiative heat simply does not appear to move quickly across the plumage. We have designed experiments for next summer that will hopefully help us to get a handle these measurements.

Last but not least Audrey Smith was also bitten by Covid restrictions for the second straight year. For the past two years she had intended to repeat studies we have done on cool-climate calliope hummingbird on warm-climate species in Arizona. However, like the rest of us she had to pivot to working with Anna’s hummingbirds. The silver lining to this shift in focus is the Anna’s is a non-migratory species that must tolerate a wide range of climatic conditions being around for both cold winters and warm summers (particularly this summer). In addition, Anna’s is also a winter breeder making them a somewhat unique species that likely have a number of thermoregulatory tools in the box.

The first thing Audrey needed to do was build a flight chamber that would fit inside our Percival environmental chamber. This gave us a chance to learn to use the laser cutters over in our Maker Hub to precisely cut the pieces which we glued together. Because we needed to image the birds with our IR camera we could not close the Percival door so instead sealed if off with plastic to allow for temperature regulation. Our initial plans were to complete trials at 5, 20, and 35 °C. However, the refrigeration unit went out so we could only do 20 and 35 °C.

Two things that had to happen prior to collecting data on a bird was that they had to be trained to 1) feed from the respiratory mask and 2) use the provided perch so that we could get post-flight perching data. Audrey discovered quickly that each bird had their own personality. Some took to the mask and perch easily and others not so much. Eventually Audrey developed some training strategies that worked for most birds. In the end Audrey got some really interesting results that now has us thinking that heat dissipation post-flight from the perch is a critical part of the body-temperature management for flight at warm temperatures. In the video below note how the bird not only heats its bill and feet, but also the leading edge of its shoulder!

While we were disappointed to not be able to travel this summer there were some really good things that came out of Project Anna’s Hummingbird. The teamwork and relationships that were established in many ways was far superior to any previous year. The entire lab functioned as a big family which was truly fun. Things appear as if they will be sort of back to normal this coming year, but even so this past summer was fun. Go Team Project Anna’s Hummingbird!!

We went back to the University of Montana Flight Lab in May to continue our long-term collaboration with Bret Tobalske’s lab on flight energetics and biomechanics of hummingbirds. This year we were joined by Bret’s Ph.D. (actually newly minted Ph.D.) Tony Lapsansky who has been collaborating with us on the heat study and Doug Warrick from Oregon State University. This year we got to use Bret’s new high-speed particle imaging velocimetry (PIV) system to look at the biomechanics of escape maneuvers as well as hovering and forward flight. This PIV system is pretty amazing in that a 2 second measurement gives us more information than we could collect in a week with the system we used for the 2005 Nature paper on rufous hummingbirds. All-in-all a really productive week!