Biometry based ageing of nestling Indian Spotted Owlets (Athene brama brama)

By

Pande, Satish
Pawashe, Amit
Mahajan, Mahadeo N.
Mahabal, Anil
Yosef, Reuven
Dahanukar, Neelesh

Type

Article

Date of Publication

2011

Original Publication

ZooKeys

Volume

132

Pages

75-88

Subjects

Age , Biometry , Flight-Predictor , Nestling , Spotted Owlet

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.132.1346

 

Abstract

Biometric analysis helps in sex differentiation, understanding development and for studies of avian biology such as foraging ecology, evolutionary ecology, and survivorship. We suggest that biometry can also be a reliable, practical and inexpensive tool to determine the age of nestlings in the field by non-invasive methods. As an example we studied the biometry of wing, culmen, talon, tarsus and body mass of nestling southern Indian Spotted Owlets (Athene brama brama). Based on the growth pattern analysis using logistic growth model, discriminant analysis and CHAID (Chi-squared Automatic Interaction Detection) based decision tree, we show that biometry of nestling Spotted Owlets is an easy, reliable and inexpensive method to determine nestling age and to assess growth rate and relative nutritional status. These biometric parameters also allow us to predict their ability to initiate first flight from the nest site. This method is described here for the first time and we postulate that such charts can be devised for other avian species as well, so as to assist conservation biologists and bird rescuers.