170 BULLETIN 197, UNITED STATES NATIONAL MUSEUM 



young in its brood ; f urtliermore, it returns to its young by reason of a 

 memory for location, not necessarily because the young are sighted or 

 heard. 



By the twelfth day the young cannot yet stand upright on the 

 metatarsus and hold their heads erect, yet they keep the eyes open 

 and watch objects that move about near them. When the parents are 

 screeching, the young refuse to open their mouths and they lie quiet 

 and low in the nest. After the parents have been absent for several 

 minutes, they respond to touch with the hunger reaction and seem to 

 lose their fear. The fear attitude is reestablished with the recurrence 

 of screeching and fluttering by the adults. The food call changes 

 from fsp to a husky tcheeh. The adults now become much warier, and 

 brooding practically ceases. Wlien away from the nest, the female 

 often sits near the male while he forages, as during the period previous 

 to nest-building. She procures at least half of the food of the young. 

 Occasionally she begs feebly from the male and may receive food, 

 which she eats herself. The male seldom brings food to be delivered 

 to the young by the female, but instead he feeds it directly to them. 



By the fifteenth day the young are well feathered, the tips of the 

 remiges forming a continuous flight surface. The weight of juveniles 

 on the sixteenth day nearly reaches tliat of adults, there being no de- 

 cline in weight previous to this time although the rate of increase is 

 relatively more gradual during the two or three days preceding. It is 

 likely that in the wild a marked drop in weight follows departure 

 from the nest. In the brood raised in captivity a decline of about 

 4 or 5 grams accompanied the first efforts of the young to hop about 

 outside of the nest box. At this age the young in the wild squat low in 

 the nest when approached by the observer and, when pulled from the 

 nest, jump and flutter in their efforts to escape. They are belligerent 

 and peck at the hand when captured. Handling of the young, and 

 their screeches, make the adults frantic, and at such times both parents, 

 in their excitement, have been heard giving the begging notes. "\'\nien 

 the juveniles are left on the ground they hop about giving a note indi- 

 cated as screig^ which is uttered at intervals of 10 to 20 seconds. The 

 sound appears to be a "location note," that is, it serves to indicate to 

 the parents the changing locations of the young. The young progress 

 on the ground by hopping, the entire length of the metatarsus touching 

 the ground. In trees and bushes they perch and jump distances of 

 ?> to 6 inches, often falling and fluttering frantically as they cling to 

 twigs and regain their balance. Progression on the ground or in trees 

 is always upward. Young once removed from the nest when replaced 

 usually will not remain but move off through the surrounding brush 

 and, reaching a distance of several feet, sit motionless. In one in- 

 stance, however, three young returned to a nest from the surrounding 

 tree, a distance of at least 10 feet. _ 



