Dr. Zuluaga is a recent graduate of Dr. Ray Danner’s lab at UNC Wilmington. His recently published research found that through acclimatization, birds can use less energy to keep cool in the summer. With the N.C. Sea Grant and N.C. Coastal Reserve Coastal Research Fellowship, he’s building on his previous research, which identified two new ways that birds seasonally adjust to changes in heat (called acclimatization). Previously, it was thought that birds adjusted to seasonal temperature changes by regulating their metabolism -- birds tend to increase their metabolism in winter to generate more heat and lower their metabolism in summer to generate less heat and therefore cool down more efficiently. But Juan discovered that birds also make seasonal adjustments through changes in behavior and possibly changes to heat exchange through the body surface (https://doi.org/10.1242/jeb.245772). With this fellowship, he is studying those two processes at the Bird Island Reserve. He surveyed common behaviors that birds use to cope with heat (panting, wing spreading, laying flat), and with thermal imaging he can determine where on the bird’s body most heat dissipates.
“We hypothesize that species that make the greatest adjustments, or those that make their adjustments slowly, are at greater risk when encountering heatwaves than species that don’t adjust their physiology to handle heat. My team and I are testing this hypothesis using non-invasive thermal imaging and behavioral analyses.” - Juan Zuluaga
In September 2024, Zuluaga and his team finished their field season, which involved collecting thermal images and behavioral samples of 70 different species. Now, they’re working on extracting and analyzing data from the thermal images. With this, they will be able to see how species acclimatize to heat, and to test for differences between species. The hope is that by describing patterns in acclimatization, they will be able to provide valuable information on which species are at risk of heatwaves. Zuluaga explains that “this research is an important step in turning our understanding of physiology into insights for wildlife conservation.” And that's exactly what this fellowship provides, an opportunity to conduct research on an understudied Reserve site -- Bird Island Reserve – and discover information that will help Reserve managers in bird conservation efforts.
Outreach is an important part of this fellowship. Can you talk about your outreach efforts?
“Doing this research has allowed me to develop two new outreach efforts. First, this entire project wouldn’t have happened without my team, which is composed of undergraduate students from UNC Wilmington. I recruited Brandt and Roberto from Futuros En STEM, an organization where LatinX undergraduate students can connect with early career researchers in STEM fields (science, technology, engineering, and mathematics). I have mentored Brandt and Roberto since last year, and they have blossomed into excellent, dependable, and experienced field biologists. Tyler, a senior at UNC Wilmington and our lab coordinator, has led the charge to extract and analyze data from thermal images. Angela, a K-12 student that I mentor through an online research platform, has contributed to data extraction from thermal images, and she is conducting her own independent research project using thermal images gathered during this field season. These students have been involved with the project from start to finish, and they have learned to conduct high-quality research using thermography and behavioral analyses. They also gained experience with scientific writing as we worked on this technical project report.
I also coordinated three presentations in the field with the Bird Island Stewards. I joined the stewards as they led about 30 members of the community on a nature walk in the Bird Island Reserve on Wednesdays during the summer. I served as a speaker during these tours, which allowed me to share my research and to describe the impact that conserving this beautiful habitat has for research, education, and stewardship.”
Keep reading to learn more about Juan and how he became a scientist:
Why did you become a scientist? What drew you to the field and what are you looking forward to?
I was very lucky to grow up on the move. To give you a frame of reference, I went to eleven different elementary schools between Colombia and the east coast of the US. Even though my family moved a lot, the one constant was that I always enjoyed being outside, whether it was visiting my grandparents’ farm in the valleys of Santander, Colombia, catching lizards in Orlando, Florida, or exploring the woods behind my house in Charlotte, North Carolina. I was always enthralled by the different animals that I encountered in the diverse habitats that I experienced while growing up. I then gravitated towards science courses in high school, and after that, I focused on getting undergraduate research experience. I then worked hard to find funding to go to graduate school, and this is where I deepened my love for science and biology. None of my family members were scientists, so for most of my life, I didn’t know that this was a career path – I just thought it was an interest or a passion. I’ve learned that interest and passion make this career a wild and enjoyable ride, and I look forward to continuing my research while guiding students from diverse backgrounds towards a career in science.
What is your favorite aspect of your research?
My favorite aspect of my research is that I always feel like I’m chasing something. In the beginning, research is just an idea that you chase. You can feel the idea forming, and you chase that feeling by reading past literature to inform your idea until it becomes a testable hypothesis. Then, you start chasing down systems, or habitats, where you can test that hypothesis. Next, you chase after sources of funding to make your idea happen. Once you have the funding, you chase down the logistical elements: your team, the equipment, and the plans to put these pieces in the right place at the right time. Then, you chase the data; in our case, we didn’t chase birds, but we did slowly approach them as we measured their surface temperatures and sampled their behaviors. Once you have the data, you chase patterns in the data. And finally, once you ultimately catch those patterns, you get to share your findings with others, and the cycle starts again. It’s a rush, every single time.
Where is Juan now?
Juan successfully defended his PhD in November 2024, and is now in Antarctica helping Dr. Steve Emslie and his PhD student, Valerie Muñoz, dig up ancient penguin remains for stable isotope analyses. Meanwhile, he has been taking thermal images of live birds whenever he gets the chance! He is using the same non-invasive methods that he developed during the North Carolina Coastal Research Fellowship! After Antarctica, he will head to the University of Tennessee, where he’s secured a postdoctoral position in Dr. Liz Derryberry’s lab. There, he will continue to apply thermal imaging and behavioral analyses.
