title: Ontogeny of aerial righting and wing flapping in juvenile birds.
abstract: Mechanisms of aerial righting in juvenile chukar partridge (Alectoris chukar) were studied from hatching to 14 days-post-hatching (dph). Asymmetric movements of the wings were used from 1 to 8 dph to effect progressively more successful righting behaviour via body roll. Following 8 dph, wing motions transitioned to bilaterally symmetric flapping that yielded aerial righting via nose-down pitch, along with substantial increases in vertical force production during descent. Ontogenetically, the use of such wing motions to effect aerial righting precedes both symmetric flapping and a previously documented behaviour in chukar (i.e. wing-assisted incline running) hypothesized to be relevant to incipient flight evolution in birds. These findings highlight the importance of asymmetric wing activation and controlled aerial manoeuvres during bird development and are potentially relevant to understanding the origins of avian flight.
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA devangel77b@gmail.com.
authors.forename: Dennis
authors.identifier: http://orcid.org/0000-0002-6565-8300
authors.initials: D
authors.lastname: Evangelista
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Sharlene
authors.initials: S
authors.lastname: Cam
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Tony
authors.initials: T
authors.lastname: Huynh
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Krivitskiy
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA Smithsonian Tropical Research Institute, Balboa, Panama.
authors.forename: Robert
authors.initials: R
authors.lastname: Dudley
mesh_terms: D000367:Age Factors; D000818:Animals; D001696:Biomechanical Phenomena; D005426:Flight, Animal; D046094:Galliformes / Q000254:growth & development*; D009068:Movement / Q000502:physiology*; D012420:Running / Q000502:physiology*; D014921:Wings, Animal / Q000502:physiology*
keywords: aerodynamics; control; development; flight origins; manoeuvrability; wing