The right wind is needed when the insect flies long over the sea

Are India’s dragonflies able to fly 200 km across the sea to Africa? Lund researchers have shown that the observations can be correct.

Many were skeptical when marine biologist Charles Anderson in 2009 presented his hypothesis about the long-distance migrating sail dragonfly. In the Maldives he had observed “Pantala flavescens”, which had probably come there from India. But when they took off, they instead steered the cow towards East Africa.

With a weight of 300 milligrams and a distance of 200 miles over the open sea, the sailing dragonfly would hold the record for distance versus body size. It writes Lunds university.

Could the trip be feasible? The matter has now been investigated, in a collaboration between Lund University, Stockholm University and the University of Exeter and Nanjing’s Agricultural University in China.

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Based on the physiological aspects, the researchers have calculated how long a dragonfly’s energy storage can keep it flying. It turned out that the reserves are not enough all the way, but the insect also needs to have the right wind in its back, conditions that prevail during certain parts of the year.

In the researchers’ simulations, wind models showed that only 15 percent of the dragonflies survive the flight to Africa, while as many as 40 percent manage the journey back to India. The study is published in the journal Frontiers in Ecology and Evolution.


Full speed on barrel from the JH factory in Sävsjö

AB Johansson & Hällgren was founded on 15 February 1897 by three brothers led by sheet metal worker Karl Johansson. It quickly developed into a thriving company in Sävsjö in Småland. In 1944, the industrial part was spun off and renamed the JH factory, or JH factories as the company was also called. The factory […]