Meeting Abstract

20.6  Friday, Jan. 4  Morphological, dietary and phylogenetic convergence in the diurnal birds of prey BRIGHT, J.A.*; COBB, S.N.; MARUGAN-LOBON, J.; RAYFIELD, E.J.; University of Bristol; Hull York Medical School; Universidad Autonoma de Madrid; University of Bristol j.bright@bristol.ac.uk

Birds are one of the most diverse clades of modern vertebrates, and have historically been regarded as a classic group in which to study adaptation through evolution. Different lineages of birds often display remarkable convergence in their cranial and beak morphologies, frequently presumed to be associated with similarity in dietary niche. We tested this assumption by performing Geometric Morphometric (GMM) analyses within a subset of neognathous birds, the diurnal birds of prey. Recent molecular phylogenies have classified this group as polyphyletic. There are therefore multiple examples of convergence within this subset of birds, for instance between the falcons (Falconidae) and hawks (Accipitridae), or between the Old World vultures (Accipitridae) and New World vultures (Cathartidae). Three-dimensional landmarks and semi-landmarks were collected from the beaks and skulls of diurnal raptors. Principle Components Analysis shows that carrion feeders (the Old and New World vultures) tend to cluster together in morphospace regardless of phylogeny, indicating strong morphological as well as dietary convergence. However, despite obvious dietary convergences, Falconids plot separately to all other Accipitrids. Thus it seems that although dietary niche may be predicted based on cranial morphology in some families, ecology alone is insufficient to explain the variety of forms seen in the diurnal birds of prey. This may reflect the fact that many raptors hunt and kill with the talons not the beak, meaning that talon morphology may additionally predict dietary ecology. Further functional analysis of the range of talon and beak forms will aim to test this.