Fledging in altricial birds : Parental manipulation or sibling competition?
In altricial birds, the period of parental investment covers three distinctly separated phases: Incubation, feeding of nestlings, and feeding of fledglings in the family group. The transition between the latter two phases occurs when the brood fledges and leaves the nest. To investigate which party, parents or offspring, initiates nest leaving, different-aged broods were swopped between nestboxes