The intriguing annual migration of the dragonfly species, Pantala flavescens
was reported almost a century ago (Fraser 1924). The multi-generational,
transoceanic migration circuit spanning from India to Africa is an astonishing
feat for an inches-long insect. Wind, precipitation, fuel, breeding, and 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 Djikstra's path-planning
algorithm. Energetics calculations reveal a Pantala flavescens can endure 90
hours of steady flight at 4.5m/s. We incorporate active wind compensation in
Djikstra'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. Finally, our timely sighting in
Cherrapunji, India (25.2N 91.7E) and a branched network hypothesis connect the
likely origin of the migration in North-Eastern India with Pantala flavescens's
arrival in South-Eastern India with the retreating monsoons; a clue to their
extensive global dispersal.Comment: 22 pages, 9 figure