Generally speaking, does the same pair use the same box for each nest they make in a season? The second brood for my pair just fledged five days ago. I haven’t seen the fledglings yet, but I hear the male in a neighboring field where they often go. Today a pair is energetically building a new nest in the same box (I’ve cleaned it out). If it were the same pair, wouldn’t they typically wait until the fledglings are a bit more self-sufficient. Could it be a different pair???
And since I feed mealworms yearound, I wonder if my “primary” pair is the same two birds for several years in a row.