In 2009, it was hypothesised that globe skimmer dragonflies (Pantala flavescens) can migrate thousands of kilometres across the Indian Ocean, from India via the Maldives to Africa, and back again. Now, an international research team led by Lund University in Sweden used models and simulations to verify this.
Marine biologist Charles Anderson observed globe skimmer dragonflies in Maldives, which had flown in from, he assumed, India. When they flew off again, it was towards East Africa.
Since the dragonflies are too small to be fitted with transmitters, the researchers examined physiological aspects and calculated how long a globe skimmer dragonfly could stay airborne using the energy that can be stored in its body. In addition, the researchers used meteorological wind models to determine if there are winds that can facilitate the migration.
The found that it was indeed possible for the dragonflies to migrate from India to East Africa and return to India. The globe skimmer dragonfly does not rely on fat stored in its body to fly such long distances. Instead, it takes advantage of favourable winds present during certain periods of the year.
According to the simulated migration experiments using wind models, about 15% of the dragonflies could manage the migration from India to Africa in the spring. In the autumn, 40% could make the same journey in the opposite direction.
