The Powers lab collected data on hummingbirds for nearly a month at the Southwestern Research Station (SWRS) from the latter part of May to late June. Collectively we gathered data on nighttime body temperature management, daytime body mass management, and evaporative heat dissipation during hovering. Collaborator Anusha Shankar (Stony Brook University) and Sarah arrived two weeks before the rest of us to finish up measurements showing use of shallow torpor by hummingbirds. Once Don and Natalie arrived measurements of daytime body mass management and evaporative heat dissipation began. While the evaporation measurements were less successful than we hoped, we still ended our time at SWRS with tons of good data.
Don Powers and Natalie Amodei traveled to Missoula, MT for the lab’s annual trip to work with Dr. Bret Tobalske. Over the years this has been a fruitful collaboration resulting in several publications relating to hummingbird physiology and biomechanics. This year we continued efforts to gather measurements of total evaporative heat dissipation in hovering calliope hummingbirds (Selasphorus calliope) before hopefully expanding these measurements to other species in Arizona next month.
The Powers Lab began 2018 with their annual trip to the Society for Integrative and Comparative Biology (SICB) meeting in San Francisco, CA (January 3-7). Traveling to the meeting to present their research data were Don Powers along with undergraduate researchers Isabelle Hoyven Cisnaros and Kaheela Reid. Don presented the lab’s continuing work on heat dissipation by hovering hummingbirds at high environmental temperature. Both students also presented with Isabelle presenting her work on nighttime body temperature management by hummingbirds and Kaheela presenting her work on how hummingbirds might dissipate heat from their bills. Lab collaborators Bret Tobalske (University of Montana), Anusha Shankar (Stony Brook University) and Jeff Yap (Simon Fraser University) were also at the meeting and made presentations. Anusha presented some additional data on hummingbird nighttime body temperature management and Jeff presented our collaborative work in reproductive energetics in zebra finches. In all the lab was involved in five presentations make for a successful meeting!
The Powers Lab just wrapped up the 2017 field season at the Southwestern Research Station (SWRS) in the Chiricahua Mountains, SE Arizona. We were joined this year by Anusha Shankar, who along with research student Isabelle Cisneros, tackled the difficult task of tracking overnight changes in hummingbird body temperature. Our primary goal in this study was to see if hummingbirds use regulated shallow torpor (hypothermia) as an alternative to deep torpor at night. The protocol called for the birds to be outside (natural light and temperature cycles) in an open container that would allow them to just leave when they woke up in the morning. Ultimately we got some great data, but both Anusha and Isabelle the days continually modifying the chambers reducing the large plexiglas box that was originally designed to a small cubical that would place the bird in good filming position. In the end we got some great data, including one bird that appears to have used regulated shallow torpor!
Research student Kaheela Reid was also with us in Arizona to do experiments measuring the influence of evaporative heat dissipation on resting metabolic rate in hummingbirds. We ended up have significant system design issues that prevented us from getting any good data, but we will work on this back in the lab and perhaps try again next year.
We are not back in the lab crunching number and preparing for the many we will be doing in the coming months!
Just returned from Dr. Bret Tobalske’s lab at the University of Montana. This was our first trip into the field this year. Along with research student Emma Bloomquist we collected infrared thermography, hovering metabolic rate, evaporative water loss, and particle image velocimetry data at both high and low temperature. We will use these data to determine 1) if hummingbirds can compensate for the loss of passive heat dissipation with evaporative heat dissipation at high temperatures during hovering, and 2) if hummingbirds can balance their heat budgets at high temperature during hovering. We also collected data for a side project….study to see if hummingbirds can dissipate heat via their bill. Now, on to analysis!