I may have counted the eyasses incorrectly at Riverside.  Both Saturday and Sunday, I only saw two eyasses on the nest.  I went back to my photographs from Thursday, and it might be possible that I mistook a wing for a head in a few of the photographs.  Until I see three heads for sure, I think it would be best if I revised my count to two, with a possible third.

In any case, the warm weather and sunlight encouraged the nestlings to be very active on Sunday.