Data from: Hovering hummingbird wing aerodynamics during the annual cycle

The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle—especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna's hummingbird (Calypte anna). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing's leading-edge differs from the attached vorticity structure that was typically found over insects' wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies.Aerodynamic loadsAerodynamic loads for all tested wingssecond_third_moment_butterFc_40_wInst_SurfaceArea9p12.matComplete wing chordwise z=0.25PIV measurements of the complete wing at z=0.25 at all tested angles of attackPIV_chordwise_full_z_0p25.matComplete wing chordwise z=0.5PIV measurements of the complete wing at z=0.5 at all tested angles of attackPIV_chordwise_full_z_0p50.matComplete wing chordwise z=0.75PIV measurements of the complete wing at z=0.75 at all tested angles of attackPIV_chordwise_full_z_0p75.matP1-4 wing chordwise z=0.25PIV measurements of the P1-4 wing at z=0.25 at all tested angles of attackPIV_chordwise_P1P2P3P4_z_0p25.matP1-4 wing chordwise z=0.5PIV measurements of the P1-4 wing at z=0.5 at all tested angles of attackPIV_chordwise_P1P2P3P4_z_0p50.matP10 wing chordwise z=0.5PIV measurements of the P10 wing at z=0.5 at all tested angles of attackPIV_chordwise_P10_z_0p50.matP10 wing chordwise z=0.75PIV measurements of the P10 wing at z=0.75 at all tested angles of attackPIV_chordwise_P10_z_0p75.matComplete wing spanwisePIV measurements of the complete wing at all tested angles of attackPIV_spanwise_full.matP1-4 wing spanwisePIV measurements of the P1-4 wing at all tested angles of attackPIV_spanwise_P1P2P3P4.matP89 wing spanwisePIV measurements of the P89 wing at all tested angles of attackPIV_spanwise_P8P9.ma