Non-destructive evaluation of wild birds under field conditions indicate
cues of inter and intra specific competition
Abstract
Digital images have become cheap, yet its perspective issues cause
hindrance for size and shape estimations. Here, we quantified shape
distortions due to projective issues using Cardboard model fishes. We
identified that Generalized Procrustes Analysis preserves shape
homogeneity where objects differ in angle up to 20° are grouped as
similar ones. For 2D shape analysis, the proposed novel filter criterion
aids in profitable use of images with minor projective issues. Using the
proposed filter criterion images of free ranging Painted Storks
(Mycteria leucocephala), taken under field conditions, were subjected
for shape analysis. Our result indicates that a subtle difference was
noted in the mandibular shape of Painted Storks between two habitats
viz., Delhi Zoo and Keoladeo National Park, which indicates a cue of
intra and interspecific competition. This study deserve merits as the
entire exercise has been done without disturbing or capturing birds
which highlights the value of animal welfare.