Bird wings act as a suspension system that rejects gusts

Cheney, J A; Stevenson, J P J; Durston, N E; Song, J; Usherwood, J R; Bomphrey, R J; Windsor, S P

Abstract

Musculoskeletal systems cope with many environmental perturbations without neurological control. These passive preflex responses aid animals to move swiftly through complex terrain. Whether preflexes play a substantial role in animal flight is uncertain. We investigated how birds cope with gusty environments and found that their wings can act as a suspension system, reducing the effects of vertical gusts by elevating rapidly about the shoulder. This preflex mechanism rejected the gust impulse through inertial effects, diminishing the predicted impulse to the torso and head by 32% over the first 80 ms, before aerodynamic mechanisms took effect. For each wing, the centre of aerodynamic loading aligns with the centre of percussion, consistent with enhancing passive inertial gust rejection. The reduced motion of the torso in demanding conditions simplifies crucial tasks, such as landing, prey capture and visual tracking. Implementing a similar preflex mechanism in future small-scale aircraft will help to mitigate the effects of gusts and turbulence without added computational burden.

Citation

Cheney, J. A., Stevenson, J. P. J., Durston, N. E., Song, J., Usherwood, J. R., Bomphrey, R. J., & Windsor, S. P. (2020). Bird wings act as a suspension system that rejects gusts. Proceedings of the Royal Society B: Biological Sciences, 287(1937), 20201748. https://doi.org/10.1098/rspb.2020.1748

• Journal Article Type: Article
• Acceptance Date: Sep 25, 2020
• Publication Date: Oct 21, 2020
• Deposit Date: Oct 30, 2020
• Publicly Available Date: Oct 30, 2020
• Journal: Proceedings of the Royal Society B: Biological Sciences
• Print ISSN: 0962-8452
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 287
• Issue: 1937
• Pages: 20201748
• DOI: https://doi.org/10.1098/rspb.2020.1748
• Keywords: General Biochemistry, Genetics and Molecular Biology, General Immunology and Microbiology, General Agricultural and Biological Sciences, General Environmental Science, General Medicine
• Public URL: https://rvc-repository.worktribe.com/output/1375074