Why the rises?

Monday morning I visited a local Nebraska farm pond. I caught several decent bass on a Gerbubble popper in shallow water. Fish exhibited splashy rises with frequency, more intensely with increasing heat. I noticed many dragon flies as the morning progressed. Also, bluegill beds were evident, yet that spawn appeared to be over. Any notion as to what might have caused the active feeding?

There are probably enough fish in the pond that they have to feed all of the time.
My guess is that competition for food is sever.

Rick