Birds repurpose the role of drag and lift to take off and land

Diana D. Chin*, David Lentink*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

12 Citaten (Scopus)
32 Downloads (Pure)


The lift that animal wings generate to fly is typically considered a vertical force that supports weight, while drag is considered a horizontal force that opposes thrust. To determine how birds use lift and drag, here we report aerodynamic forces and kinematics of Pacific parrotlets (Forpus coelestis) during short, foraging flights. At takeoff they incline their wing stroke plane, which orients lift forward to accelerate and drag upward to support nearly half of their bodyweight. Upon landing, lift is oriented backward to contribute a quarter of the braking force, which reduces the aerodynamic power required to land. Wingbeat power requirements are dominated by downstrokes, while relatively inactive upstrokes cost almost no aerodynamic power. The parrotlets repurpose lift and drag during these flights with lift-to-drag ratios below two. Such low ratios are within range of proto-wings, showing how avian precursors may have relied on drag to take off with flapping wings.

Originele taal-2English
TijdschriftNature Communications
Nummer van het tijdschrift1
StatusPublished - 1-dec.-2019
Extern gepubliceerdJa

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