Alexander Smith used his Summer Undergraduate Research Fellowship to explore how the bugs’ cyclical emergence changed some animals’ feeding habits around the Triangle.
The emergence of millions of cicadas across North Carolina caused a buzz in parts of Chapel Hill and the Triangle this spring as Brood XIX surfaced for the first time in 13 years.
For Alexander Smith, the arrival of the periodical cicadas around Carolina’s campus also presented an opportunity for research.
Smith, a senior biology major, was curious how this year’s addition of millions of bugs would impact the food web dynamics of insects and their predators, including birds, reptiles, arachnids and small mammals.
“When periodical cicadas are introduced into an ecosystem and into a food web, it’s going to alter that food web,” said Smith, who received a Summer Undergraduate Research Fellowship (SURF) grant from the Office for Undergraduate Research to support his work.
A passion for the outdoors
Smith works in the laboratory of biology professor Allen Hurlbert, his SURF advisor. The laboratory experience and community have been central to Smith’s past year at Carolina.
Smith, 28, describes himself as a non-traditional student. After graduating high school, he served in the Army before pursuing the first years of his college career at Cleveland Community College. He transferred to Carolina knowing he wanted to pursue a career related to his love for animals and the outdoors, which he has had since childhood.
“I grew up in Casar, North Carolina,” said Smith. “It’s on the back side of South Mountain. My grandfather owns a ranch out there, and he passed it down to me. So, my weeks are pretty full. During the weekdays, I’m doing research. On the weekends, I’m taking care of cattle.”
Smith began working in the Hurlbert laboratory as a volunteer, an opportunity he discovered through a class project in an introductory biology course. Eventually, his volunteer work on an ongoing local bird population project turned into a more permanent position with the research team.
Counting caterpillars
The Hurlbert laboratory focuses, in part, on research related to birds and their food sources and leads Caterpillars Count!, a citizen science project that encourages community members to count and report the insects and spiders they find in their backyards.
Caterpillars, Smith said, are excellent sources of nutrition for birds and their fledglings.
Clay versions of the bugs, he continued, make great decoys and allow him and fellow researchers to study which animals are present in the area by the bite and strike marks they leave behind on the soft green clay.
“A bird strike will normally be a completely clean ‘V’ shape, like a cut,” said Smith. “Arthropods will normally leave two little indents. Very small mammals, when they’ve been chewing on it, you’ll see the teeth marks.”
So far this summer, Smith has deployed 600 clay caterpillars at five sites across the Triangle area, including UNC’s campus, Eno River State Park in Durham and Prairie Ridge in Raleigh. When he returns to a site one week after he attaches the clay caterpillars to branches of bushes and trees, he makes note of the types of marks and, importantly, the quantity of caterpillars that have them.
Smith anticipates that there will be fewer bite and strike marks on the caterpillars deployed during the height of Brood XIX’s emergence compared to caterpillars deployed before and after, indicating that the birds were choosing the readily available cicadas over the caterpillars.
Anecdotally, he has already observed this in the field. But it will take analyzing his data from the summer deployments back in the Hurlbert laboratory before he is able to present his findings.
Along with writing a research paper, Smith will share his work at the annual Celebration of Undergraduate Research in spring 2025. He said that support and collaboration from Hurlbert, Ph.D. student and researcher Ivara Goulden and his lab mates have made the experience one of the most memorable parts of his time as a Tar Heel.
“It honestly is a wonderful lab environment. We all have different projects that we’re working on, but we help each other out. And that just makes the work environment better.”
Photos and story by Jess Abel, College of Arts and Sciences