Like many birds, and the Monarch butterfly, the beautiful Common Green Darner is a migratory creature. Much less is known about it and other migratory insects, however. What is known about the Green Darner is astounding: it accomplishes its travels over the course of three generations, with a multigenerational range between 373 and 1,553 miles. If you see this dragonfly in River Forest or nearby, it may have arrived here from southern Illinois, or from the Carribean.
For a fascinating account of the research and data collection – both citizen and professional – behind this knowledge, see this article from the Vermont Center for Ecostudies.