Long before this time the manner of the parents had changed. In the first place, they were more busy; foraging industriously on the ground, coming within ten or fifteen feet of us, without appearing to see us at all. In fact they had, after the first day, paid no attention to us, for we never had disturbed them, never went to the nest till sure that both were away, and kept still and quiet in our somewhat distant seat.
About this time they began to show more anxiety in their manner. The first exhibition was on the fourth day since we knew the young were hatched (and let me say that I _believe_ they were just out of the shell the morning that we found the father feeding). On this fourth day the singer perched near the nest-tree, three or four feet from the ground, and began a very loud wren "dear-r-r-r! dear-r-r-r! dear-r-r-r!" constantly repeated. He jerked himself about with great apparent excitement, looking always on the ground as if he saw an enemy there. We thought it might be a cat we had seen prowling about, but on examination no cat was there. Gradually his tone grew lower and lower, and he calmed down so far as a wren can calm, though he did not cease his cries. I did not know he could be still so long, but I learned more about wren possibilities in that line somewhat later.
During this performance his mate came with food in her beak, and evidently saw nothing alarming, for she went to the nest with it. Still he stood gazing on the ground. Sometimes he flew down and returned at once, then began moving off, a little at a time, still crying, exactly as though he were following some one who went slowly. The call, when low, was very sweet and tender; very mournful too, and we got much wrought up over it, wishing--as bird students so often do--that we could do something to help. He was roused at last by the intrusion of a bird into his domain, and his discomfiture of this foe seemed to dispel his unhappy state of mind, for he at once broke out in joyous song, to our great relief. That was not the last exhibition of the wren's idiosyncrasy; he repeated it day after day, and finally he went so far as to interpolate low "dear-r-r's" into his sweetest songs. Perhaps that was his conception of his duty as protector to the family; if so, he was certainly faithful in doing it. It was ludicrously like the attitude of some people under similar circumstances.