In 2013, a group of researchers led by entomologist Gerard Talavera discovered several Vanessa cardui butterflies on a beach in French Guiana, South America. These butterflies migrate an incredible 14,500 km from Europe to sub-Saharan Africa but make necessary stops along the way for rest and energy replenishment.
To reach South America, they have to fly non-stop across the Atlantic Ocean. The tiny Vanessa cardui butterfly takes advantage of favorable wind blowing from the Sahara desert in Africa to South America to complete this incredible 5-8 days journey across the sea. Researchers have been studying why these butterflies can accomplish such long journeys for the past decade.
Recently, their published research in Nature Communications on June 25 revealed that wind conditions likely aided the butterflies in making their transatlantic trip from West Africa. By analyzing weather data, genetic sequences, and isotopes in the butterflies’ wings, the scientists confirmed they had come from West Africa and Europe and found specific plant pollen on their bodies from two shrub species that only bloom in West Africa.
The study also highlighted the crucial role of wind in butterfly migration, estimating that without aid of wind, their journey would be limited to around 780 km due to energy consumption constraints. The Saharan Air Layer facilitates their long-distance flight by transporting dust from the Sahara desert to South America and even Florida. This layer of wind is vital for their success as it allows them to alternate between active flight and gliding with the breeze.
