A dragonfly migration three generations long

Biologists found the common green darner’s migration lasts three generations. ©Mike Ostrowksi

The migration of the monarch butterfly (Danaus plexippus), from the highland of Mexico to fields and backyards throughout North America is well known. But what about the journey of the green darner? A new paper in Biology Letters describes the full life cycle of a dragonfly for the first time. Researchers found the common green darner (Anax junius) takes three generations to complete its annual cycle. One generation migrates north in the spring. The second heads south in the fall. The third occupies its southern range throughout the winter. “There are massive insect declines going on around the world,” says Peter Marra, director of the Smithsonian Migratory Bird Center and second author on the paper, “so understanding these complex biological patterns is essential to determine why different populations might be declining.”

Read more at phys.org, and read the study here.