RESEARCH ARTICLE


Nestling Development of Ring-necked Parakeets (Psittacula krameri) in a Nest Box Population



Michael P. Braun, Michael Wink*
Heidelberg University, Institute of Pharmacy and Molecular Biotechnology, Department of Biology, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany


© 2013 Braun and Wink

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Heidelberg University, Institute of Pharmacy and Molecular Biotechnology, Department of Biology, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany; Tel: 0049 (0) 6221 544881; Fax: 0049(0) 6221 544884; E-mails: psittaciden@yahoo.de; Wink@uni-hd.de


Abstract

Chick development of a population of non-native Ring-necked Parakeets (Psittacula krameri) (RNP) has been investigated between 2006 and 2008 in Heidelberg, Germany. In parrots hatching asynchrony is common. RNP chicks are under natural selection to fledge synchronously with their siblings, as parents return less often to the nest after the first chick has fledged and remaining chicks may starve. Female nestlings apparently outperform the males by about one d in body mass gain, but also had higher measurements in tarsus, wing and tail growth. This was unexpected as adult males are generally larger than females. First-hatched chicks showed lowest biometrical values as compared to their younger siblings in several characters like body mass gain, bill, wing, and tail length. This feature may contribute to a synchronization of fledging in an otherwise asynchronous brood.

Keywords: Parrots, Psittaciformes, fledging synchronization, invasive species.