Dancing turtles unlock scientific discovery – UNC Chapell Hill

Carolina researchers publish a groundbreaking study on how turtles navigate using the Earth’s magnetic field.When captive loggerhead sea turtles anticipate food, they do a little dance. The turtles raise their heads out of water, open their mouths, flap their flippers and spin in circles.Not only is this “turtle dancing behavior” cute, it was also the key to unlocking a significant scientific discovery by researchers at UNC-Chapel Hill.The prestigious international science journal Nature published the study Feb. 12. Kayla Goforth, a recent doctoral graduate in the College of Arts and Sciences’ biology department, is the lead author of “Learned magnetic map cues and two mechanisms of magnetoreception in turtles.”Early on in her graduate studies at Carolina, Goforth was fascinated by sea turtles returning to the same feeding sites again and again throughout their lifetimes — despite traveling up to 10,000 miles across the planet. She hypothesized that these turtles used Earth’s magnetic field to memorize specific geographic areas that they associated with food, and she devised an experiment in the biology department’s Lohmann Lab — run by husband-and-wife duo Kenneth and Catherine Lohmann.“Kayla began to wonder if we could get the turtles to associate the magnetic signature of a geographic area with food — and therefore act out this turtle dance behavior,” said Kenneth Lohmann, the Charles P. Postelle Jr. Distinguished Professor of Biology. “She really took the lead in this. I wasn’t at all sure in the beginning whether it would work, but we were happy to have her try, and it turned out remarkably well.”The team of Carolina researchers analyzed how sea turtles use Earth’s magnetic field to guide their long-distance migrations across the ocean, and how the turtles sense magnetic fields.Goforth and the rest of the all-Carolina team conditioned loggerhead turtles to magnetic fields replicating those that exist in various oceanic locations, repeatedly feeding the turtles in some magnetic fields while not feeding them in others. When later exposed to the fields in which they were fed, the turtles exhibited “turtle dancing behavior,” indicating that they associated that specific magnetic signature with food.“That’s how we figured out what to measure, just by watching them do this as we were feeding them in the lab,” said Goforth, who is now conducting postdoctoral research at Texas A&M University. “When they get really excited, they stick their heads out; they slap their flippers wildly; they spin in place sometimes.”The assay suggests that loggerhead sea turtles can learn the magnetic signatures of geographical areas — much like dropping a pin in a GPS app.The groundbreaking study was published in the prestigious international science journal Nature. (Ken Lohmann/biology department)When turtles use magnetic signatures, they are using their magnetic map sense, but they also have a magnetic compass sense that enables them to move north, south or some other direction. The research further showed that the map and compass senses detect magnetic fields in different ways.Working in collaboration with the College’s physics and astronomy department, the team investigated the effects of radiofrequency oscillating magnetic fields on the turtles’ magnetic senses. What the team found surprised them. The oscillating magnetic fields had no impact on the turtles’ magnetic map ability but did disrupt the turtles’ ability to use the magnetic compass and orient themselves.“It suggested there are two different mechanisms for the magnetic map and compass,” Goforth said. “And they might have evolved separately.”Exactly how turtles and other migratory species use these senses is a question that has baffled scientists for more than 50 years, and it’s one that Goforth continues to research at Texas A&M, now studying monarch butterflies instead of sea turtles.“The big question is always the mechanism,” Goforth said. “What’s the mechanism and what is the sensor? We know that for the visual sense, you have eyes; for the sense of smell, you have a nose; and for hearing, you have ears. But no receptor like that has been identified for the magnetic sense, and the mechanism remains unknown.”(Ken Lohmann/biology department)Penny-Gordon Larsen, vice chancellor for research, writes about the proposed cap on federal research funding. Ross W. Lampe Jr.’s $20 million investment will transform the Lampe Joint Biomedical Engineering department.Ronit Freeman uses nature’s building blocks to create innovative technologies to detect and fight disease.Two Carolina graduate students share a passion for computer science and love for each other.Doctoral candidate Adrienne Bonar studies the many factors that shape people’s feelings.The internship allowed doctoral candidate Sarah Brown to do real-world criminology research at RTI International.Following Hurricane Helene, professor Saif Khairat’s team created a map to pinpoint who needed help and where.Identified by Carolina astronomer Madyson Barber, the “baby” planet is 3 million years old and roughly the size of Jupiter.© 2024 The University of North Carolina at Chapel Hill

Source: https://www.unc.edu/posts/2025/02/12/dancing-turtles-unlock-scientific-discovery/