(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.


Figure 2


Fig. 2. Net rate of energy gain (W) of black-headed gulls (A,C,E) and lesser black-backed gulls (B,D,F) for flapping (broken line) and soaring flight (solid line) solved for equal air speeds and ground speeds (m s-1). (A,B) En=20 W, D=10000 m, (C,D) En=20 W, D=5000 m, (E,F) En=10 W, D=10000 m. tp is kept constant because its effect on R is inverse to that on D.