Dr. Henry Pollock, a Postdoctoral Research Associate at the University of Illinois at Urbana-Champagne, discusses with us his recently accepted article in Functional Ecology: “Heat tolerances of temperate and tropical birds and their implications for susceptibility to climate change”, his journey into ecology, as well as his favorite (and least favorite) parts about being an ecologist.

Henry holding a Keel-billed Toucan (Ramphastos sulfuratus) captured during his dissertation fieldwork in central Panama. Photo credit: Zach Welty, 2012.

What’s your paper about?

How will birds respond climate change? One key factor is physiological tolerance to heat. In a warming world, the ability to tolerate high temperatures is of primary importance in determining the winners and losers of climate change. Although absolute rates of climate warming are lower in the tropics, lowland tropical species are often predicted to be more sensitive to even small temperature increases because they inhabit such a thermally stable environment. To test this hypothesis, we measured and compared heat tolerances of tropical and temperate bird species.

What is the background behind your paper?

An adult male Red-capped Manakin (Ceratopipra mentalis), the most commonly captured bird species in the long-term mist netting dataset. Photo credit: Diego Rincón, 2013.
An adult male Red-capped Manakin (Ceratopipra mentalis), the most commonly captured bird species in the long-term mist netting dataset. Photo credit: Diego Rincón, 2013.

Understanding the impacts that rising global temperatures are having on organisms is incredibly important in a rapidly changing world. Previous research in ectotherms has demonstrated that tropical species have lower heat tolerances than their temperate counterparts, and are predicted to be more sensitive to climate warming. In contrast, empirical estimation of the heat tolerances of endotherms is expensive and time-consuming, and very little is known about how they vary geographically. We addressed this knowledge gap by measuring avian heat tolerances to test (1) whether they differed between tropical (n = 58) and temperate (n = 23) bird species and (2) whether tropical birds are more sensitive to heat than their temperate counterparts, as has been found in ectotherms.

What does your work contribute to the field?

Although more and more research groups are beginning to measure avian heat tolerances, this is the first explicit comparison between temperate and tropical species. Our findings show that birds may not exhibit such strong patterns of latitudinal variation in sensitivity to climate warming, as has been reported in ectotherms. Thus, tropical birds (at least those in lowland mesic habitats) may be more resilient to rising temperatures than previously expected.

What is the next step in this field going to be?

We need more measurements of heat tolerances in endotherms! Our paper is a step in the right direction, and contributes to a small but growing body of literature, including a recent wealth of studies of heat tolerances of desert birds (led by Dr. Blair Wolf, University of New Mexico and Dr. Andrew McKechnie, University of Pretoria). However, we still know woefully little about how avian heat tolerances vary geographically, and which bird species will truly be able to “take the heat.”

How did you get involved in ecology?

Henry holding a lizard at the long-term mist netting study site. Photo credit Sean MacDonald, 2014.
Henry holding a lizard at the long-term mist netting study site. Photo credit Sean MacDonald, 2014.

 It all started in high school, when I took a Field Biology class with my one of my favorite teachers, Mr. Stone. The main project for the class was to create an arthropod collection, and in doing so, I found myself captivated by the diversity of species and the process of identifying and classifying the world around me. However, I didn’t truly want to become an ecologist until I studied abroad in Costa Rica while in university. It was my first true field experience – we travelled all over the country, living at field stations, and I got my first exposure to being in a tropical forest. I never looked back, and have continued conducting field work and learning about organisms in their environments ever since.

What are you currently working on?

I am currently a postdoctoral research associate at the University of Illinois at Urbana-Champaign. I have teamed back up with my former Ph.D. advisor, Dr. Jeff Brawn, and we are using a long-term mist netting dataset to understand how tropical bird demography and abundance has changed over time at our study site in central Panama. This research has been ongoing for 43 years and running (1977-present) and is one of the longest tropical bird population studies in the world. I am incredibly excited to be a part of it!

What is the best thing about being an ecologist?

There are so many great things about being an ecologist – from getting to chase animals for a living to developing a deeper appreciation for the natural world through careful observation. I’d have to say that the best thing, however, is the travel. My work has led me to far-flung locations including Panama, Equatorial Guinea, Borneo, and the tiny island of Guam in the Western Pacific, to name a few.

What is the worst thing about being an ecologist?

The infamous Harpy Eagle (Harpia harpyja) that attacked Henry during his dissertation fieldwork. Photo credit Torrey Rodgers, 2011.
The infamous Harpy Eagle (Harpia harpyja) that attacked Henry during his dissertation fieldwork. Photo credit: Torrey Rodgers, 2011.

The worst thing was getting attacked by a harpy eagle during the first year of my PhD in Panama. It was rehabilitated and released at my field site, and little did I know, but it had been fed out of a backpack by a guy in a baseball cap, which just so happened to be my field garb at the time. I got eight stitches and had whiplash for three days afterwards. It definitely increased my street credibility in Panama though, given that it is their national bird.

What do you do in your spare time?

I have always loved languages, and I am currently working on learning Italian. I am a crossword fiend and I like to read. I also enjoy running and cycling, hiking and naturalizing (primarily birding but open to all possibilities), and writing raps that nobody else likes in my spare time.

You can read more about Dr. Pollock’s research here and read the paper in full here.