<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The harriers (Accipitridae: <italic>Circus</italic>) represent a unique group of raptorial birds due to their hunting behaviour and their facial ruff and prominent facial disc. During previous studies it was suggested that harrier species may have other convergent features shared with owls like asymmetric or enlarged ear openings related to sensitive hearing capabilities. In this study, cranial asymmetry was done using SAGE (Symmetry and Asymmetry of Geometric Data) software. 32 skulls of 3 species (Western Marsh Harrier <italic>(Circus aeruginosus</italic>) n=8, Montagu’s Harrier <italic>(Circus pygargus)</italic> n=10, Hen Harrier <italic>(Circus cyaneus)</italic> n=14) were photographed, digitized and assigned with 2D landmarks with TpsDig software. The variables were analysed based on Generalized Procrustes analysis. The morphometric data showed cranial asymmetry of harriers. This asymmetry should rather be explained by foraging strategies as the results are corresponding to the exceptionally good hearing of these species among diurnal raptors.</p>
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The harriers (Accipitridae: Circus) represent a unique group of raptorial birds due to their hunting behaviour and their facial ruff and prominent facial disc. During previous studies it was suggested that harrier species may have other convergent features shared with owls like asymmetric or enlarged ear openings related to sensitive hearing capabilities. In this study, cranial asymmetry was done using SAGE (Symmetry and Asymmetry of Geometric Data) software. 32 skulls of 3 species (Western Marsh Harrier (Circus aeruginosus) n=8, Montagu’s Harrier (Circus pygargus) n=10, Hen Harrier (Circus cyaneus) n=14) were photographed, digitized and assigned with 2D landmarks with TpsDig software. The variables were analysed based on Generalized Procrustes analysis. The morphometric data showed cranial asymmetry of harriers. This asymmetry should rather be explained by foraging strategies as the results are corresponding to the exceptionally good hearing of these species among diurnal raptors.

The possible occurrence of cranial asymmetry in three harrier (Accipitridae: <italic>Circus</italic>) species

Behavioural Ecology Group, Department of Systematic Zoology and Ecology

Department of Anatomy, Cell- and Developmental Biology

Ornis Hungarica

This work is licensed under the Creative Commons Attribution 4.0 International License.

The possible occurrence of cranial asymmetry in three harrier (Accipitridae: ) species

The harriers (Accipitridae: Circus) represent a unique group of raptorial birds due to their hunting behaviour and their facial ruff and prominent facial disc....

The possible occurrence of cranial asymmetry in three harrier (Accipitridae: Circus) species

Published Online: Jun 22, 2021

Page range: 139 - 148

Received: May 21, 2021

Accepted: Jun 03, 2021

DOI: https://doi.org/10.2478/orhu-2021-0011

Keywords
cranial morphology, morphometrics, anatomy, skull, shape, convergent evolution, harrier, auditory system

© 2021 Tibor Pecsics et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

The possible occurrence of cranial asymmetry in three harrier (Accipitridae: Circus) species

Published Online: Jun 22, 2021

Page range: 139 - 148

Received: May 21, 2021

Accepted: Jun 03, 2021

DOI: https://doi.org/10.2478/orhu-2021-0011

Keywordscranial morphology, morphometrics, anatomy, skull, shape, convergent evolution, harrier, auditory system

© 2021 Tibor Pecsics et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
cranial morphology, morphometrics, anatomy, skull, shape, convergent evolution, harrier, auditory system