Wing-Assisted Incline Running and the Evolution of Flight

Authors

Kenneth P. Dial, University of Montana - MissoulaFollow

Document Type

Article

Publication Title

Science

Publication Date

1-17-2003

Volume

299

Issue

5605

Disciplines

Biology | Life Sciences

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.

DOI

10.1126/science.1078237

Rights

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