Fig. 9. (A) Dorsal view of a dove in a medium-speed upstroke (7 m s^-1) posture showing the three markers on the wing (shoulder, wrist and ninth primary tip) used to establish the position of the wing leading edge and the incident airflow and effective wing length. As shown in the figure, an extended proximal wing and slightly flexed distal wing (with effective length less than geometric length) are typical of a medium-speed upstroke. (B) Dorsal view of a cockatiel in mid-upstroke configuration in fast flight (11 m s^-1). Note that, although overall wingspan is similar in both species, mean dove body mass is 83 % greater than that of the cockatiels, leading to a much higher wing loading in doves.