Cross Sectional Geometry of the Forelimb Skeleton and Flight Mode in Pelecaniform Birds

Title

Cross Sectional Geometry of the Forelimb Skeleton and Flight Mode in Pelecaniform Birds

Creator

Simons E L R; Hieronymus T L; O'Connor P M

Publisher

Journal of Morphology

Date

2011
2011-08

Description

Avian wing elements have been shown to experience both dorsoventral bending and torsional loads during flapping flight. However, not all birds use continuous flapping as a primary flight strategy. The pelecaniforms exhibit extraordinary diversity in flight mode, utilizing flapping, flap-gliding, and soaring. Here we (1) characterize the cross-sectional geometry of the three main wing bone (humerus, ulna, carpometacarpus), (2) use elements of beam theory to estimate resistance to loading, and (3) examine patterns of variation in hypothesized loading resistance relative to flight and diving mode in 16 species of pelecaniform birds. Patterns emerge that are common to all species, as well as some characteristics that are flight-and diving-mode specific. In all birds examined, the distal most wing segment (carpometacarpus) is the most elliptical (relatively high I-max/I-min) at mid-shaft, suggesting a shape optimized to resist bending loads in a dorsoventral direction. As primary flight feathers attach at an oblique angle relative to the long axis of the carpometacarpus, they are likely responsible for inducing bending of this element during flight. Moreover, among flight modes examined the flapping group (cormorants) exhibits more elliptical humeri and carpometacarpi than other flight modes, perhaps pertaining to the higher frequency of bending loads in these elements. The soaring birds (pelicans and gannets) exhibit wing elements with near-circular cross-sections and higher polar moments of area than in the flap and flap-gliding birds, suggesting shapes optimized to offer increased resistance to torsional loads. This analysis of cross-sectional geometry has enhanced our interpretation of how the wing elements are being loaded and ultimately how they are being used during normal activities. J. Morphol. 272: 958-971, 2011. (C) 2011 Wiley-Liss, Inc.

Subject

allometry; Anatomy & Morphology; aves; behavior; cross-sectional geometry; evolution; flight; functional-morphology; Locomotion; long bones; pelecaniforms; phylogenies; regression; size; variables

Identifier

Format

Journal Article

Search for Full-text

Users with a NEOMED Library login can search for full-text journal articles at the following url: https://libraryguides.neomed.edu/home

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

958-971

Issue

8

Volume

272

Citation

Simons E L R; Hieronymus T L; O'Connor P M, “Cross Sectional Geometry of the Forelimb Skeleton and Flight Mode in Pelecaniform Birds,” NEOMED Bibliography Database, accessed March 8, 2021, https://neomed.omeka.net/items/show/7186.

Social Bookmarking