Scientists have recently documented the extraordinary transatlantic migration of Painted Lady butterflies, covering a staggering 2,600 miles (4,184 km) from West Africa to South America, according to a study published on Wednesday in Nature Communications.
The research, led by Gerard Talavera from the Botanical Institute of Barcelona at CSIC, unveils the longest known butterfly migration across an ocean, challenging previous understanding of insect dispersal capabilities.
A Painted lady (Vanesa cardui) butterfly, is seen in Zvernec, near the city of Vlore, some 160 km, South West of Tirana on May 27, 2024. Bright yellow, black, red and blue, Alexanor butterflies once fluttered abundantly on southwestern Albania's flowery slopes. Now, like many related species, scientists say they are disappearing due to human impacts, including climate change. Increasingly absent from the picturesque district of Zvernec, the Alexanor is one of 58 of the Balkan country's 207 butterfly species that researchers say are at risk. Photo by ADNAN BECI/AFP via Getty Images
Researchers Look Into Longest Known Butterfly Migration
The unexpected journey came to light when Talavera observed Painted Lady butterflies on the beaches of French Guiana in October 2013. Typically found in Europe and Africa, their presence in South America prompted an international investigation.
"We usually see butterflies as symbols of the fragility of beauty, but science shows us that they can perform incredible feats," researcher Roger Vila, a co-author of the study said in a press release. "There is still much to discover about their capabilities."
The research team, comprising experts from institutions including the Institute of Evolutionary Biology (CSIC-Pompeu Fabra University) and the University of Ottawa, employed a multifaceted approach to trace the butterflies' origins.
Wind pattern analysis revealed "exceptionally favorable conditions" in October 2013, supporting the possibility of a transatlantic flight. DNA examination of the butterflies showed closer matches with African and European populations, ruling out North American origins.
In a novel approach, researchers analyzed pollen attached to the butterflies using advanced molecular techniques. According to the study, the pollen DNA identified plants exclusive to Africa, providing concrete evidence of the butterflies' pre-journey feeding habits.
Isotope analysis of the butterflies' wings further confirmed their natal origin, solidifying the evidence for their African and European roots.
The team estimates the butterflies flew non-stop for 5 to 8 days, leveraging powerful trade winds. "Without wind assistance, the butterflies could have flown a maximum of 780 km before depleting their energy reserves," Toro-Delgado explained.
The Sahara's air currents, known for transporting dust across the Atlantic, were crucial in facilitating this remarkable journey.
"It is entirely possible that we are [also] underestimating the frequency of these types of dispersal events and their impact on ecosystems," Megan Reich, a study coauthor notes.
The study highlights potential implications for biodiversity and ecosystems worldwide, particularly in the context of climate change. As global warming alters wind patterns and ecological conditions, such long-distance insect migrations could become more frequent.
"Systematic monitoring of dispersing insects is crucial," Talavera stressed. "It could help predict and mitigate potential risks to biodiversity resulting from global change."
The findings are expected to spur further research into insect dispersal capabilities and their potential impact on global ecosystems, as scientists continue to unravel the mysteries of nature's most resilient travelers.
Painted Lady butterflies are not the only species known for long-distance travel. Monarch butterflies also migrate, flying for 50-100 miles a day, primarily because they cannot survive the cold winters of northern climates.
