MISQUAH — They have started gathering. Beginning about ten days ago, the adult loons on Big Pelican and Loon Lake have been drifting into loose groups at the north ends in the early mornings — six together on Big Pelican Thursday, nine on Loon Lake Sunday, birds that have spent the entire summer as fiercely territorial pairs floating within thirty feet of each other and not fighting about it.

This is staging, and it is the beginning of the end of the loon summer. Over the next several weeks the groups will get bigger and the mornings noisier, and then one day in September the adults will go, more or less together, and the lake will be quieter in a way people notice without being able to say why.

The juveniles do not go with them. They stay — weeks longer, sometimes into October, occasionally until the ice starts making the decision for them — flying the lake alone, feeding, and then leaving on their own, one at a time, for a coast none of them has ever seen. Nobody has satisfactorily explained how they know. I have read what there is to read on it and I am telling you plainly that the explanations are not as good as the fact.

Greta Solberg’s log has been running since the eggs in May, and two weeks ago she opened a page at the back and titled it LEAVING and left it empty. As of Sunday it is no longer empty. Her mother reports the first entry, written after church, reads: “The big ones are practicing being together. The two that fly do not know yet. I am not going to tell them.”