Recently I started participating in the Dragonfly Pond Watch Project run by the Migratory Dragonfly Partnership. I hear about a lot of projects like this through insect bloggers; in this case I heard about it through the Xerces Society's newsletter. This particular project tracks the migratory movements of two very common dragonflies, the Common Green Darner (Anax junius) and Black Saddlebags (Tramea lacerata). It involves periodically counting dragonflies at the same pond over the course of the fall migration period. This works well for me since an artificial pond is part of my normal walking route through my local patch, and I can just add 15 or 20 minutes to my normal route to count dragonflies there.
I mentioned in the previous paragraph that I did not see either of my target species during the count. Of course, when I walked along the river to continue my route, what do I see on the other side of the field? Black Saddlebags. And not just one, but a half-dozen or more. In their company was a Common Green Darner. If I did my watch by the basketball courts instead of at the pond, I would be recording more sightings.