Citation

Dial KP. Science 2003; 299(5605): 402-404.

Affiliation

Flight Laboratory, Avian Studies Program, Division of Biological Sciences, University of Montana (UM), Missoula, MT 59812, USA. kdial@selway.umt.edu

Copyright

(Copyright © 2003, American Association for the Advancement of Science)

DOI

10.1126/science.1078237

PMID

12532020

Abstract

Flapping wings of galliform birds are routinely used to produce aerodynamic forces oriented toward the substrate to enhance hindlimb traction. Here, I document this behavior in natural and laboratory settings. Adult birds fully capable of aerial flight preferentially employ wing-assisted incline running (WAIR), rather than flying, to reach elevated refuges (such as cliffs, trees, and boulders). From the day of hatching and before attaining sustained aerial flight, developing ground birds use WAIR to enhance their locomotor performance through improved foot traction, ultimately permitting vertical running. WAIR provides insight from behaviors observable in living birds into the possible role of incipient wings in feathered theropod dinosaurs and offers a previously unstudied explanation for the evolution of avian flight.

Language: en