Files in this Data Supplement:

• Movie 3 -

  Movie. 3. Deflection of lesser upper- and underwing coverts during flapping flight over a sea cliff, taken using onboard video camera. Interval between frames: 20 ms.

• Movie 4 -

  Movie. 4. Deflection of lesser upper- and underwing coverts during a mid-flight gust response over a sea cliff, taken using onboard video camera. Interval between frames: 20 ms.

• Movie 5 -

  Movie. 5. Gliding perching sequence (Run 9 of Table 1), taken using high-speed digital video camera. The sequence begins with a gliding approach, during which the alula begins to peel upwards and the tail is flicked up and back. The second phase of the sequence involves a rapid pitch-up manoeuvre, during which the wrist sweeps forward, the lesser underwing coverts begin to deflect from the wrist, the alula starts to protract, the wings begin to straighten, and the tail spreads and pushes downwards and forwards. Toward the end of the pitch up manoeuvre, the lesser underwing coverts deflect in a travelling wave from the wrist towards the shoulder. The final phase of the sequence is a deep stall, in which the wings are outstretched to give a parachute-like shape. Interval between frames: 2 ms.

• Movie 6 -

  Movie. 6. Flapping perching sequence (Run 14 of Table 1), taken using high-speed digital video camera. The sequence shows a flapping approach, followed by the main deceleration wingbeat, which involves a pitch-up motion of wings followed by a deep stall. The lesser underwing coverts deploy towards the end of each downstroke and close shortly after the beginning of each upstroke. Interval between frames: 2 ms.

• Movie 7 -

  Movie. 7. Gliding perching manoeuvre involving alula deflection and protraction. The alula is flush with the wing during the early stages of the gliding approach, but peels from the tip towards the end of the approach. The hand wing then begins to sweep back, causing the peeling alula to protrude further from wing surface. Finally, the alula actively protracts away from the wing. Interval between frames: 2 ms.

• Movie 8 -

  Movie. 8. Pitch-up phase of a gliding perching sequence, leading into a deep stall. Note the changing extent of deflection of the upperwing covert feathers during the deep stall. Interval between frames: 2 ms.