Today’s factismal: Dragonflies swarm either to feed or when they migrate to another area. A single swarm may have more than 1,000 individual dragonflies.
It is no secret; dragonflies are cool. Not only are they the fastest flying insect, they eat mosquitoes along with butterflies, ants, and wasps. But one of the coolest things about dragonflies is that sometimes they swarm in huge numbers; a single swarm may have more than 1,000 individuals flitting about.
But why would dragonflies group together? Most species are very territorial, simply because having too many dragonflies trying to eat too few insects means that everyone goes hungry. However, if the area has an unusual abundance of one of the insects that dragonflies prey on, then a swarm could happen. The individual dragonflies are too busy stuffing themselves to worry about arguing over who owns the area (sort of like neighbors at a barbeque). Another reason that dragonflies may band together is if they need to migrate to a new area because the ponds that they breed in have dried up or because all of the prey has vanished. As is the case with other animals that group together when they migrate, the swarming behavior provides the dragonflies with some measure of protection from things that think they are tasty and may also provide them with aerodynamic advantages. But as soon as the migration is over or the extra prey is eaten, the dragonflies go back to being territorial and everyone heads back for his own patch of pond.
Because dragonfly swarms happen infrequently and for such short times, very little is known about them. But you can help! If you ever see a swarm of dragonflies, flit over to the Dragonfly Swarm Project and tell them about your swarm along with anything else that you noticed about the area. You’ll help researchers learn more about these magnificent critters and get to watch dragonflies – win-win!