Burst muscle performance predicts the speed, acceleration, and turning performance of Anna's hummingbirds
Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability.
© 2015, Segre et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited. Received: 27 August 2015; Accepted: 13 November 2015; Published: 19 November 2015. Adam Behroozian and Tyson Read assisted with data collection. Tungesh Kapil, Janet Li, Sachiko Ouchi, Jordan Roth, Sorosh Safa, Humraaz Samra, Nandhini Sankhyan, Tom Tsou, Sherry Young, Bo Zhang assisted with behavioral scoring. This research was supported by grants from the U.S. National Science Foundation to D.L.A. (IOS 0923849) and to M.H.D. (IOS 0923802), and by a Natural Sciences and Engineering Research Council of Canada Discovery Grant (402667) to D.L.A, and a Postdoctoral Fellowship to R.D. Ethics: Animal experimentation: All procedures were conducted under approval of the Institutional Animal Care and Use Committee at the University of California, Riverside and the Animal Care Committee at the University of British Columbia. Reviewing editor: Russ Fernald, Reviewing editor, Stanford University, United States The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication. Author contributions: PSS, Conception and design, Acquisition of data, Analysis and interpretation of data, Drafting or revising the article RD, Conception and design, Analysis and interpretation of data, Drafting or revising the article. VBZ, Conception and design, Drafting or revising the article. MHD, Conception and design, Drafting or revising the article. ADS, Conception and design, Drafting or revising the article, Contributed unpublished essential data or reagents. DLA, Conception and design, Acquisition of data, Analysis and interpretation of data, Drafting or revising the article.
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