During the progress of my study I found that one of the pair, which from manners and appearance I judged to be the female, had lost a tail feather, and this one I affectionately dubbed "Swiftie." She appeared worn out with anxiety added to the confinement of a long period of incubation, and embraced every opportunity to rest, but seasons of sleep were of short duration, for it seemed that the body of the brooding bird was lifted each time a movement was felt beneath. The mate, with his sleek coat, bright eyes and calm demeanor, formed a decided contrast to the ragged, unkempt appearance of the female.
Even four days showed perceptible growth in the swiftlings. They were not allowed to remain uncovered, a wise precaution, for their bodies were perfectly naked. At this age the instinct of cleanliness began to assert itself. The weak, awkward little creatures would struggle backward from beneath the brooder, up to the edge of the nest and deposit over it that which, remaining within, would have made their home uninhabitable.
From this time forth a third Swift was seen to enter into the care of the nestlings, taking its turn at brooding and feeding. Was this a nurse-maid employed to relieve the overburdened mother, or a kind and helpful friend or neighbor, or the younger and less care-taking of two wives? Who can tell?
It was not until the sixth day after hatching that I knew to a certainty how many young birds there were. Then, to my surprise, I found there were five. They had grown to be very clamorous for food. Two, at most three (later but one), were served at one feeding, and the process was after this manner: "Swiftie" would drop into the chimney and alight below the nest, her throat bulging with the fullness of captured insects. The little ones that were hungry were alert, for all had learned that a rumbling noise in the chimney, followed by a sound of "chitter, chitter, chitter," meant something to eat. After resting a moment, the mother would scramble up over the nest, and, with closed eyes, feel about until she came in contact with an open mouth, whereupon she would place her beak far down the throat, deposit a portion of food, then seek another yawning cavity. No system appeared to be observed in the matter of feeding. The hungriest youngsters made the greatest effort to reach the source of supply.