Bionikseminar 2025
The intriguing annual migration of the dragonfly species, Pantala flavescens, was reported a century ago [1]. The multi-generational, transoceanic migration circuit spanning 14000-18000 kms, from India to Africa is an astonishing feat for an insect few cms in size. Wind, precipitation, fuel, breeding, and the life cycle affect the migration, yet understanding of their collective role in the migration remains elusive. We identify the transoceanic migration route by imposing a time constraint emerging from energetics on Dijkstra’s path-planning algorithm.
Energetics calculations reveal Pantala flavescens can endure 90 hours of steady flight at 4.5m/s. We incorporate active wind compensation in Dijkstra’s algorithm to compute the migration route from years 2002 to 2007. The prevailing winds play a pivotal role; a direct crossing of the Indian Ocean from Africa to India is feasible with the Somali Jet, whereas the return requires stopovers in Maldives and Seychelles. The migration timing, identified using monthly-successful trajectories, life cycle, and precipitation data, corroborates reported observations. While working on this problem my mind ventured into many different applications of engineering, which are all connected to the transoceanic migration of dragonflies. The applications range from designing airfoils/wings, sports aerodynamics and wind turbines to developing novel spectral accuracy algorithms for numerical simulations. Hence the ideas vary from simple mimicking of dragonflies to more complex abstractions arising from the need to understand their flying behaviour.