Calliope Hummingbirds, Escape Maneuvers, and PIV!

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!

PIV run on a calliope hummingbird.
PIV results for a calliope hummingbird flying at 6 m/s.

Latest Publications from the Powers Lab!!

Studies of zebra finch reproductive energetics in collaboration with Dr. Tony Williams lab at Simon Fraser University. Lead author on both studies was Tony’s form student Dr. Jeff Yap who is currently a postdoc at Auburn University.

Expanding Heat Dissipation During Flight Studies to Pigeons!

Quick trip to the University of Montana Flight Lab to work with Bret Tobalske and his student Cullen Flynn on a study of heat-budget management during flight in pigeons. This is our first foray in this work beyond hummingbirds. Key in this work is the use of an autonomic inhibitor to prevent the pigeons from adjusting feather position to either increase or decrease skin exposure for the purpose of controlling passive and possibly evaporative heat dissipation following a series of flights. The protocols we used in this quick experiment worked remarkably well! Stay tuned for the results.

Cullen getting a pigeon to make several short flights.
Following flight exercise measuring surface temperature using infrared thermography and recording core body temperature with a thermal pit tag.

Powers Lab Studies Keel Bone Damage in Laying Hens

The Powers Lab began work on a study of keel bone damage in laying hens in collaboration with a research group headed by Dr. Alexandra Harlander at Guelph University. The research group will also involve long time collaborator Bret Tobalske at the University of Montana. The core goal of the project will be to understand what aspects of communal housing lead to injury and mortality rates higher than for caged hens. Of specific interest will be damage to the keel bone, especially fractures, that are known to be quite painful. Susceptibility to skeletal injury is like a consequence of selection for high egg project. The increasing demand for cage-free eggs by consumers has heightened the need to understand the best ways to provide enriched environments for hens that minimize risk of injury.

The Powers Lab will oversee experiments designed to assess the energetic cost of keel bone injury to the hens. This will include measurement of both resting and active metabolic rates, including metabolic rate during short-term flights. We will also measure daily energy expenditure using doubly labeled water. Our work on the project officially started on December 11 when Don traveled to the University of Montana to train Dr. Neila Ben Sassi, a postdoc on the project, and graduate student Renee Garant on open-flow respirometry and blood sample collection for doubly labeled water. While in Montana we used rock pigeons for the training sessions since Bret had already trained them to wear the respirometry mask needed for some measurements.

From left to right Neila, Don, Bret, and Renee!! The whole gang in the Flight Lab!
Rock pigeon wearing a respiratory mask for demonstration of using open-flow respirometry to measure the metabolic cost of short flights.

Once things get into full swing Don and possible one of the undergraduate researchers will likely make a trip to Guelph mid-summer to help with the work.








Powers Lab Travels to SICB

This week the Powers Lab travel to Austin, TX for the Society for Integrative and Comparative Biology (SICB) meeting. Undergraduate researches Elliot Shannon and Nathaniel Shiiki presented posters on the work they did in Arizona this past Summer, while lab PI Don Powers gave a talk on his most recent work on heat dissipation during hovering in calliope hummingbirds done in collaboration with Dr. Bret Tobalske’s lab at the University of Montana. Once again both Elliot and Nathaniel did amazing jobs with their presentations receiving praise from many who attended their poster sessions.

Elliot ready to present his poster at SICB!
Nathaniel ready to present his poster at SICB!
Don giving his talk at SICB!

This year’s SICB meeting was particular rewarding as we got to spend time with former undergraduate researchers in the Powers Lab Sean Powers (yes, Don’s F1) and Keely Corder. Sean is currently a Ph.D. student at Virginia Commonwealth University in Richmond, VA and Keely is a Ph.D. student at the University of Montana.

Sean Powers presenting his research on gypsy moths at SICB!

It was also great to reconnect with many friends and colleagues from across the world. It was good to spend time Dave Swanson (University of South Dakota, and GFU alumnus), Todd McWhorter (University of Adelaide), Anusha Shankar (University of Alaska), Hugh Ellis (University of San Diego), Ken Welch (University of Toronto), Blair Wolf (University of New Mexico), Bob Mason (Oregon State University), Chris Clark (University of California, Berkeley), Kimberly Sheldon (University of Tennessee), and many others. It was also fun to meet and chat with several graduate students who expressed interest in the work we do in the Powers Lab. All in all the meeting was a very productive time both professionally and personally.

Sean Powers presenting at SICB

Powers Lab crew at SICB

Opening plenary session at SICB

Nathaniel prenting to Dr. Jon Harrison from Arizona State University

Elliot working his poster at SICB

Dr. Sheila Patek, Duke University, giving the plenary at SICB

Don wrapping up his talk at SICB