Fledging in altricial birds: Parental manipulation or sibling competition?

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Standard

Fledging in altricial birds : Parental manipulation or sibling competition? / Nilsson, Jan Åke; Svensson, Mikael.

I: Animal Behaviour, Vol. 46, Nr. 2, 01.01.1993, s. 379-386.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

APA

CBE

MLA

Vancouver

Author

RIS

TY - JOUR

T1 - Fledging in altricial birds

T2 - The British Journal of Animal Behaviour

AU - Nilsson, Jan Åke

AU - Svensson, Mikael

PY - 1993/1/1

Y1 - 1993/1/1

N2 - 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 in two passerine bird species, the marsh tit, Parus palustris, and the pied flycatcher, Ficedula hypoleuca. Parents did not try to manipulate nestlings into nest leaving; fledging was thus independent of the level of parental investment. Instead, fledging occurred when one of the nestlings, which had reached a certain threshold size, left the nest in order to approach the parents and obtain additional feedings at the expense of its siblings. It is suggested that the fledging time of altricial birds is determined by energetic considerations and by sibling competition. Since fledging also represents the juvenile's transition from an inactive to an active party in the parent-offspring interaction, it is also to be considered as an escalation of the parent-offspring conflict.

AB - 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 in two passerine bird species, the marsh tit, Parus palustris, and the pied flycatcher, Ficedula hypoleuca. Parents did not try to manipulate nestlings into nest leaving; fledging was thus independent of the level of parental investment. Instead, fledging occurred when one of the nestlings, which had reached a certain threshold size, left the nest in order to approach the parents and obtain additional feedings at the expense of its siblings. It is suggested that the fledging time of altricial birds is determined by energetic considerations and by sibling competition. Since fledging also represents the juvenile's transition from an inactive to an active party in the parent-offspring interaction, it is also to be considered as an escalation of the parent-offspring conflict.

U2 - 10.1006/anbe.1993.1200

DO - 10.1006/anbe.1993.1200

M3 - Article

VL - 46

SP - 379

EP - 386

JO - The British Journal of Animal Behaviour

JF - The British Journal of Animal Behaviour

SN - 1095-8282

IS - 2

ER -