Scaling and functional morphology in strigiform hind limbs

Rayfield, Emily J.; Madan, Meena A.; Bright, Jen A.

Abstract

© The Author(s) 2017. Strigiformes are an order of raptorial birds consisting exclusively of owls: the Tytonidae (barn owls) and the Strigidae (true owls), united by a suite of adaptations aiding a keen predatory lifestyle, including robust hind limb elements modified for grip strength. To assess variation in hind limb morphology, we analysed how the dimensions of the major hind limb elements in subfossil and modern species scaled with body mass. Comparing hind limb element length, midshaft width, and robusticity index (RI: ratio of midshaft width to maximum length) to body mass revealed that femoral and tibiotarsal width scale with isometry, whilst length scales with negative allometry, and close to elastic similarity in the tibiotarsus. In contrast, tarsometatarsus width shows strong positive allometry with body mass, whilst length shows strong negative allometry. Furthermore, the tarsometatarsi RI scales allometrically to mass0.028, whilst a weak relationship exists in femora (mass0.004) and tibiotarsi (mass0.004). Our results suggest that tarsometatarsi play a more substantial functional role than tibiotarsi and femora. Given the scaling relationship between tarsometatarsal width and robusticity to body mass, it may be possible to infer the body mass of prehistoric owls by analysing tarsometatarsi, an element that is frequently preserved in the fossil record of owls.

Citation

Rayfield, E. J., Madan, M. A., & Bright, J. A. (2017). Scaling and functional morphology in strigiform hind limbs. Scientific reports, 7, Article 44920. https://doi.org/10.1038/srep44920

• Journal Article Type: Article
• Acceptance Date: Feb 3, 2017
• Online Publication Date: Mar 22, 2017
• Publication Date: 2017-04
• Deposit Date: Nov 28, 2019
• Publicly Available Date: Dec 2, 2019
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 7
• Article Number: 44920
• DOI: https://doi.org/10.1038/srep44920
• Keywords: Palaeontology; Skeleton
• Public URL: https://hull-repository.worktribe.com/output/3267721
• Additional Information: Received: 28 June 2016; Accepted: 3 February 2017; First Online: 22 March 2017; : The authors declare no competing financial interests.
• Contract Date: Nov 28, 2019