Tiny transmitters could unlock monarch migration mysteries in Florida
Every spring, many monarch butterflies drift back into Florida on orange-and-black wings that have captivated scientists for generations. They arrive quietly, fluttering through fields and roadsides, stopping at nectar plants to feed and to lay eggs on patches of milkweed. Soon their offspring emerge and begin dispersing across the landscape.
What happens next has long remained one of the biggest unanswered questions in monarch migration research.
Now, researchers at the University of Florida are preparing to follow the butterflies in a way that was impossible until recently — using tiny solar-powered radio transmitters light enough to ride on the backs of monarch butterflies as they move through North Central Florida.
The effort is part of a collaboration involving Monarch Watch, the Xerces Society for Invertebrate Conservation, Disney Conservation, the U.S. Fish and Wildlife Service and the University of Miami.
At UF, the project is led by Jaret Daniels, curator of Lepidoptera at the Florida Museum of Natural History and professor in the UF/IFAS Department of Entomology and Nematology, whose lab has spent years studying monarch migration, ecology and conservation in Florida.
“For decades, we’ve known monarchs return to Florida every year, but we still don’t fully understand where many of them go afterward or how they move across the landscape,” Daniels said. “These tags give us a chance to begin answering those questions in real time.”
The BlūMorpho transmitters, which weigh about as much as a grain of rice, recently drew national attention for their ability to track migrating monarch butterflies across North America using solar-powered radio technology.
Researchers say the technology could significantly expand scientific understanding of monarch migration, one of the world’s most recognizable insect migrations.
For Daniels, the Florida component of the project is especially meaningful because it builds on more than three decades of continuous monarch monitoring at a site in Cross Creek, east of Gainesville.
The work began with pioneering monarch researcher Lincoln Brower, widely regarded as one of the leading figures in monarch butterfly science. Brower and collaborators started documenting monarch “remigration” into Florida more than 35 years ago, creating one of the longest-running data sets of its kind.
Daniels first participated in the surveys as a graduate student at UF under renowned lepidopterist Thomas Emmel. Today, he oversees the annual monitoring effort, continuing a research legacy that spans generations of UF researchers.
“Lincoln Brower inspired generations of researchers to study monarch migration and conservation,” Daniels said. “To now have tools that can potentially answer questions he spent his career pursuing is incredibly exciting.”
The project also reconnects UF researchers and alumni shaped by Brower’s influence. Among them is Ray Moranz, a UF alumnus and former Brower student who now works with the Xerces Society and is partnering with Daniels on the effort.
Together, researchers hope the tags will help solve longstanding questions about monarchs returning to Florida each spring.
Researchers now know that some monarch butterflies produced in Florida continue north each spring, helping to recolonize the eastern United States. However, questions remain about how many make the journey, how they navigate North Florida’s landscape and how environmental conditions affect their survival.
“We know Florida plays an important role in the monarch life cycle, but many details are still missing,” Moranz said. “This technology allows us to move beyond snapshots and actually follow the butterflies’ journeys. In April, our initial results showed a few adults moving north to Georgia and Alabama. In May, we saw even more movement north, including a monarch that flew from the heart of the UF campus to southeastern Ohio in less than three weeks.”
The tagging initiative complements Daniels Lab conservation projects already underway across the state, including a partnership with the Florida Department of Transportation to expand monarch breeding habitat along Florida roadsides. That project will result in more than 15,000 native milkweed plants being added along transportation corridors designed to support pollinators and other wildlife.
Monarch populations in North America have declined in recent decades because of habitat loss, pesticide exposure and environmental change. Researchers hope the tracking technology will help guide future conservation efforts for monarchs and other migratory insects.
“Monarchs connect people to nature in a very personal way,” Daniels said. “Every new piece of information helps us better understand and protect one of the most recognizable insects in the world.”
