Painted lady butterflies brave record 8-day, 2,600-mile transatlantic flight

Painted Lady butterflies were observed completing an epic 2,600 miles (4,200 km) flight across the Atlantic from West Africa to French Guiana before arriving in South America.

These remarkable butterflies flew across the Atlantic in just 5 to 8 days, propelled by favorable trade winds.

“We usually see butterflies as symbols of the fragility of beauty, but science shows us that they can perform incredible feats. There is still much to discover about their capabilities,” said Roger Vila, a researcher at the Institute of Evolutionary Biology (CSIC-Pompeu Fabra University) and co-author of the study.

Extensive DNA analysis of butterflies and pollen

It all started with a surprising observation in 2013.

Back then, Gerard Talavera, a researcher from the Botanical Institute of Barcelona at CSIC, spotted Painted Lady butterflies fluttering on the beaches of French Guiana. Normally, Painted Lady butterflies ( Vanessa cardui) are found in Europe and Africa.

This unexpected appearance brought together an international team of researchers to unravel their origin through the collection of extensive scientific evidence.

They used a combination of cutting-edge techniques to track the migration of these mysterious butterflies.

The researchers began their investigation by mapping the wind patterns to see if these butterflies could have traveled across the Atlantic. Interestingly, they discovered “exceptionally favorable wind conditions” that prevailed throughout October 2013.

Further, they studied the butterflies’ DNA and compared them to populations worldwide. DNA revealed a closer match with African and European populations. This genetic evidence strongly suggested they didn’t originate in North America, further supporting the theory of an epic journey across the ocean.

They also employed advanced molecular techniques to study pollen that clung to the butterflies. The DNA analysis of the pollens identified plants found only in Africa, suggesting that the butterflies feasted on African flowers before their incredible transatlantic flight.

Lastly, they studied isotope signatures to look for tiny chemical markers in the wings and determined their natal origin. This revealed their possible European birthplace.

“It is the first time that this combination of molecular techniques including isotope geolocation and pollen metabarcoding is tested on migratory insects. The results are very promising and transferable to many other migratory insect species. The technique should fundamentally transform our understanding of insect migration,” said Clément Bataille, associate professor in the Department of Earth and Environmental Sciences at the University of Ottawa.

Traveled non-stop

The butterflies originated most likely originated in Europe and extended their flight by over 4000 miles (7000 km).

The researchers predict that these insects flew continuously for 5 to 8 days, thanks to a favorable wind pattern.

As per the press release , the Sahara’s powerful air currents played a crucial role in their journey.

“The butterflies could only have completed this flight using a strategy alternating between active flight, which is costly energetically, and gliding the wind. We estimate that without wind, the butterflies could have flown a maximum of 780 km before consuming all their fat and, therefore, their energy,” explained Eric Toro-Delgado, one of the article’s co-authors.

Scientists plan to use this discovery to learn more about insect migration and the impact of climate change.

The findings have been published in the journal Nature Communications.