A frenzy. At least that’s what it looked like when I first arrived at the pool. In retrospect, I arrived at the pool at about the same time as four dragonflies. They were all flying around. All wings. None had settled. It took a couple of minutes to sort out that there were only four.
They settled. There were two males; a Twelve-spotted Skimmer and a Yellow-sided Skimmer. There were two females; a Common Green Darner and, I believe, a Yellow-sided Skimmer.
The Twelve-spotted Skimmer appeared to believe it was his pool. Periodically he would buzz the male Yellow-sided Skimmer. The latter took it all in stride. He would simply fly a couple of circuits and settle on the same or another grass stalk. On occasion, he even settled on the same grass stalk as the Twelve-spotted Skimmer.
At the same time, the two females set about laying eggs.
The Common Green Darner settled on a clump of grass at the waterline and appeared to lay eggs around its base. Before she had finished, she had laid eggs at a couple of locations in the pool.
The other female whom I believe was a Yellow-sided Skimmer also appeared to lay eggs, In contrast to the Common Green Darner, this dragonfly executed a series of small vertical oval circuits, dipping her abdomen in the water that the bottom of each circuit. I assumed she was laying eggs too.
After the females had completed their tasks, they flew away, leaving the males to occupy the pool in a somewhat uneasy peace.