Hummingbirds are a highly agile group of flyers capable of moving in all directions. In this work we measured Anna’s hummingbirds (Calypte anna) within a wind-tunnel in order to compare forward, still-air hovering and backward flight. We describe bird body and wingbeat kinematics by high-speed videography as well as flight metabolic rate using respirometry. Our findings suggest that the energetic cost of backward flight is similar to that of forward flight at comparable speeds. For further reading: Sapir, N. and Dudley, R. 2012. Backward flight in hummingbirds employs unique kinematic adjustments and entails low metabolic cost. Journal of Experimental Biology 215:3603-3611; See also http://www.nytimes.com/2012/10/02/science/for-hummingbirds-its-easy-to-shift-into-reverse.html?_r=0.
