Ecological effects on morphometric development of the Indian Eagle Owl Bubo bengalensis

Abstract

Univariate analysis based on logistic growth curve fitting and multivariate analysis using principle component analysis (PCA) were used to analyze complex patterns and correlations in morphometric data from 16 individuals of the Indian Eagle Owl Bubo bengalensis from the Deccan Plateau. Wing chord length, tarsus length, claw length, beak length, tail length and weight were measured from hatching until fledging (1-58 days old) . A logistic growth curve showed a good fit for all characters. Different characters showed different growth patterns according to their function in the developing nestling. PCA analysis revealed that different morphological characters are loosely coupled together during growth, and this could be attributed to the behavioural ecology of nestlings. By comparing the patterns in our data with data published from southern India, we also show that there is plasticity in the development in these geographically isolated populations.

The time budget and behavioural traits of young and adult Indian Eagle Owl Bubo bengalensis (Franklin, 1831) (Aves: Strigiformes: Strigidae) in and around a nesting site: a preliminary report

“…4) Pellet regurgitation: The time it took when the young began gaping to the time they ejected pellets. 5) Flapping: During the evening hours the young spent some time performing flapping exercises, presumably in preparation of flying which is possible only around 58 days (Pande & Dahanukar 2011).…”