Wind compensation and flight in tailwind by dragonfly species Pantala flavescens, during the transoceanic migration

The dragonfly species Pantala flavescens (PF), perform the longest known insect migration (14-16000 kms) annually between India and Africa bridging two distant ecologies and, is consequently of tremendous importance amidst rising climate change concerns. Field observations of transoceanic insect migration are unavailable due to the lack of lightweight trackers for dragonflies; therefore, we developed a blend of wind tunnel experiments and theory to study the migration route, timing, and the role of wind. We propose a novel energetics model and modified Dijkstra's path planning algorithm to identify the migration network, timing, and favorable winds. The migration from Africa to India (~2800kms) is completed in merely 45 hours non-stop with assistance from the strong Somali jet; the return journey originates in north-east India involving a complex network of stopovers in southern India, Sri Lanka, Maldives, Seychelles stretching over months; thus, highlighting the critical role of winds. Our wind tunnel experiments reveal that PF actively compensates for crosswind to remain on course. Also, thrust production dominates tailwind flight to enhance the distance covered in contrast to lift generation in headwind flight. Finally, we highlight how climate change endangers this migration.