In a world first, scientists have discovered that painted lady butterflies have flown across the world without stops, covering at least 4,200 km (2,600 miles). It upends what we know about butterfly migration and behaviour.
Scientists believe the trip took five to eight days, potentially half the butterflies' adult lifespan. What's more, these globe trotting creatures may actually be flying even longer distances - 7,000 km (4,350 miles) or more - from western Europe to Africa and on to South America.
Researchers from the University of Ottowa and Spain's Institute of Evolutionary Biology confirmed this stunning insight into the secret lives of butterflies using a suite of genetic detective work, after a flock of Vanessa cardui were discovered on the Atlantic coast of South America, in French Guiana, far from the species' known range. So, they must have flown from Africa to South America, across the Atlantic.
"The butterflies could only have completed this flight using a strategy alternating between active flight, which is costly energetically, and gliding the wind," said study co-author Eric Toro-Delgado, a scientist at the Institute of Evolutionary Biology in Barcelona. "We estimate that without wind, the butterflies could have flown a maximum of 780 km (485 miles) before consuming all their fat and, therefore, their energy."
The team used historical records of wind trajectories leading up to the butterflies' discovery in October 2013. They were then able to see that favourable trade winds made this epic transatlantic journey viable, which is an astounding new insight into the migratory behaviour of insects.