Dragonfly Migration Revealed

Billions of common green darner dragonflies (Anax junius) migrate every year but until now hardly anything was known about their routes or strategy. New research into the migration behavior is available from a team of researchers from Princeton University. Detailed flight path information was made possible by tiny radio transmitters developed by the team. A transmitter weighing about a third of a gram was attached to green darner dragonfly's thorax with a couple of drops of superglue and some eye-lash adhesive. Then a team tracked the movements by following the signals from a receiving airplane.

According to this article in BBC Science, the dragonflies tended to only move after two nights of cooler temperatures, indicating a cold front was approaching with favourable north-westerly winds. They also tended to change direction when they met a large body of water, ensuring they never became stranded out over the sea. Two insects were recorded flying out over the ocean before reversing and skirting down the coastline. The data also revealed that the dragonflies' migration patterns are strikingly similar to those of songbirds, suggesting there is a strong evolutionary link to their behaviors.