For the first three days tapping the nest or even movement of it caused by wind would elicit begging. By the fifth day at nest 2-a (1959) only vigorous agitation of the branch to which the nest was attached evoked any response. At this nest on June 16, 1959, one young begged while the other cowered. Cowering is correlated with opening of the eyes, as the young bird that begged had its eyes only partly open. Both young cowered on June 19, 1959. Table 9 summarizes the maturation of the nestling Bell Vireos. TABLE 9. MATURATION OF NESTLING BELL VIREOS. THE FIRST DAY THAT AN ACTIVITY WAS OBSERVED IS SHOWN. ================================================================== | Day of nestling life +---+---+---+---+---+---+---+---+---+----+---- | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 --------------------+---+---+---+---+---+---+---+---+---+----+---- | | | | | | | | | | | Eyes open | | | | x | | | | | | | Feathers erupt | | | | | x | | | | | | Sound: Squeak | x | | | | | | | | | | _Chee_ | | | | x | | | | | | | Begging | x | | | | | | | | | | Cowering | | | | | | | | x | | | Head scratching and | | | | | | | | | | | Preening | | | | | | | | | x | | Hopping to rim of | | | | | | | | | | | nest | | | | | | | | | x | | Fledging | | | | | | | | | | |x[G] --------------------+---+---+---+---+---+---+---+---+---+----+---- [G] This is the commonest fledging day. _Parental Behavior_ No eggshells were found in nests on the days of hatching. Presumably they had been removed by the parents. Nolan (1960:234) indicates immediate disposition of the eggshell after hatching. Lawrence (1953:62) suggests that conspicuous removal of eggshells by the female Red-eyed Vireo informs the male that the young have hatched. Both sexes brood and the exchange of partners resembles that described for the incubation period. Decrease in brooding in the daytime begins about the sixth day of nestling life. Nolan (1960:235) reports a sharp decrease in brooding when the oldest nestlings are seven days old. Brooding decreases notably on the sixth day of nestling life in the Red-eyed Vireo (Lawrence, 1953:62). Nice (1929:17), Hensley (1950:244), and Nolan (1960:235) report that the female Bell Vireo assumes a slightly greater role in brooding than the male.