Send to

Choose Destination
Sci Adv. 2017 May 17;3(5):e1603041. doi: 10.1126/sciadv.1603041. eCollection 2017 May.

How birds direct impulse to minimize the energetic cost of foraging flight.

Author information

Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.


Birds frequently hop and fly between tree branches to forage. To determine the mechanical energy trade-offs of their bimodal locomotion, we rewarded four Pacific parrotlets with a seed for flying voluntarily between instrumented perches inside a new aerodynamic force platform. By integrating direct measurements of both leg and wing forces with kinematics in a bimodal long jump and flight model, we discovered that parrotlets direct their leg impulse to minimize the mechanical energy needed to forage over different distances and inclinations. The bimodal locomotion model further shows how even a small lift contribution from a single proto-wingbeat would have significantly lengthened the long jump of foraging arboreal dinosaurs. These avian bimodal locomotion strategies can also help robots traverse cluttered environments more effectively.


aerodynamic force platform; bimodal locomotion; birds; energy; flight; foraging; impulse; landing; takeoff; theropod

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center