The wing phalanges (Phalanx proximalis digiti majoris) of European Accipitriformes and Falconiformes

Ida Horváth,Tibor Pecsics,Jenő Eugen Kessler

doi:10.2478/orhu-2021-0022

Abstract

Abstract The authors compared the first phalanx of the second wing finger of 33 European diurnal raptors. The importance of studying this bone lies in the fact that, although it has diagnosable characteristics, it was practically neglected by osteologists and paleontologists. Thus, fossil materials can be identified through them, as well as those from owl pellets. The comparison was made possible by the comparative avian skeleton collection of the Hungarian Natural History Museum. In a preliminary investigation we examined the morphological diversity of the first phalanx of the second wing finger among the different species. We used principal component (PC) analyses on measurements. The PC described the curvature of the anterior surface of the bone and the relative size of the distal and proximal epiphyses. The principal component analysis showed slightly overlapping in shape between the taxons but the accipitriform and falconiform birds diverged in the morphospace. The attributes and geometry of the first phalanx of the second wing finger reflects more on taxonomic background than flying behaviour. The avian wing is a complex and highly modulable structure, therefore, probably body mass and size affect flying performance than the other morphological features of this bone. The text is supplemented by 6 figures and one size table.

Highlights

The authors discuss a lesser-known part of the avian skeleton used for description
The relatively simple first phalanx of the second wing finger is rather small, even in the largest avian species – only 6–7 centimetres long, and even though it bears excellent diagnostic characteristics, it has never been the focus of experts studying avian bones
We examined the morphological variability of the first phalanx of the second wing finger

Summary

Introduction

The authors discuss a lesser-known part of the avian skeleton used for description. The relatively simple first phalanx of the second wing finger is rather small, even in the largest avian species – only 6–7 centimetres long, and even though it bears excellent diagnostic characteristics, it has never been the focus of experts studying avian bones. There are virtually no study results, or most of the time not even a mention. Of the four wing phalanges only one bears such morphological characteristics, namely the first phalanx of the second wing finger. Its morphometrical analysis results can be used for comparative anatomical, paleontological, archaeological, taxonomical or ornithological examinations of owl pellets. The morphological terminology and measurement method of the skeletal part was used based on the works of Baumel et al 1979 and Kessler 2013.

Objectives

Conclusion