Meeting Abstract

80.4  Wednesday, Jan. 6  Comparative aerodynamic performance of hummingbird wings from Colombia LENTINK, D*; KRUYT, J.W.; QUICAZAN, E.M.Q.R. ; GUSSEKLOO, S.W.S.; ALTSHULER, D.L.; VAN LEEUWEN, J.L.; Experimental Zoology Group, Wageningen University, 6709PG Wageningen, The Netherlands.; Experimental Zoology Group, Wageningen University, 6709PG Wageningen, The Netherlands.; Department of Biology, University of California, Riverside, CA 92521, USA; Experimental Zoology Group, Wageningen University, 6709PG Wageningen, The Netherlands.; Department of Biology, University of California, Riverside, CA 92521, USA; Experimental Zoology Group, Wageningen University, 6709PG Wageningen, The Netherlands. david.lentink@wur.nl

Hovering is a key behavior of hummingbirds that allows them to time-effectively extract nectar from flowers and catch arthropod prey, which is critical to their high-energy lifestyle. The aerodynamic and inertial power demands are high during hovering but how these demands compare among different species is, however, not fully understood. Here we compare the aerodynamic quasi-steady performance of wings from 12 species of hummingbirds from Colombia to determine how wing morphology mediates hovering performance. We attained lift and drag over a range of angle of attack for Reynolds numbers below 10,000. Whereas other spinner experiments recorded negative drag at low angles of attack, our spinner measured drag accurately across the full range of wing angles. The accurate drag and lift measurements combined allow us to compare not only aerodynamic lift, but also glide ratio and more relevant, the power factor. The power factor captures the efficacy of hummingbird wings to lift a unit weight with a minimum of aerodynamic power. We contrast these aerodynamic results with estimates of inertial power and show that there is a tradeoff between aerodynamic and inertial power that is critical to our understanding of hummingbird flight.