The research by Harvard integrative physiologist Andrew A. Biewener and fellow researchers was publicly funded through the National Science Foundation (NSF) and published in the Jan. 23 edition of Nature.

NSF is an independent federal agency that supports fundamental research and education across all fields of science and engineering.

The research has broad-ranging impact since the power curves provide graphical insight into how muscles are used to produce power for flight at different speeds. Knowledge of flight capabilities would be useful in natural environment studies of issues such as bird migration and a bird's flight ecology. The data might also be useful in the development of more efficient robotic aerial vehicles, where factors such as thrust and forward velocity are paramount.

Birds were used in the study because they rely primarily upon a single pectoralis muscle in each wing to fly. It is difficult to measure mechanical power output in other animals since most use multiple, distributed muscles for locomotion. In comparison, humans have 45 muscles in the thigh, leg and foot region alone, most of which are active during locomotion.

The researchers established mechanical power curves for cockatiels (Nymphicus hollandicus) and turtledoves (Streptopelia risoria) by measuring the wing and body movements as the birds flew at various speeds in a wind tunnel. They also used highspeed video to record from multiple angles the length changes of the birds' pectoralis muscle. These data were applied to a computer model of aerodynamic power output. When analyzed with other data collected, the r
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Contact: Manny Van Pelt
mvanpelt@nsf.gov
703-292-8070
National Science Foundation
22-Jan-2003