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

Michael P Braun,Michael Wink

doi:10.2174/1874453201306010009

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.

Highlights

The Ring-necked Parakeet (RNP) (Psittacula krameri) is the most successful introduced parrot with established populations in at least 24 countries worldwide
Development and growth of RNP nestlings is illustrated in Fig. (1)
Body mass shows a linear increase with time within the first 25 d, and stays at a plateau for approximately 5-10 d before decreasing towards fledging

Summary

Introduction

The Ring-necked Parakeet (RNP) (Psittacula krameri) is the most successful introduced parrot with established populations in at least 24 countries worldwide. The RNP is a strictly herbivorous parrot and feeds on buds, flowers, shoots, seeds, and fruits. It only rears one brood per year. RNP breed both in single pairs and in colonies with up to nine couples in one tree [5].The females occupy nests long before the 1st egg is laid and defend their cavities against competitors, especially other female RNP. Chicks hatch asynchronously as the female starts incubation as soon as the 1st egg has been laid. The chicks are still being fed by their parents, especially by the father for at least two weeks. Fledglings gather in groups, while parents separate themselves from the young, and later from each other [10]

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