Wing loadings, wing shapes, and flight capabilities of procellariiformes

Among 48 procellariiform species wing loading increases with increasing body weight. Mean total wing area varies allometrically with mean body weight: log 10 wing area (cm 2 )=20.42 log 10 body weight (g) 0.588 . The power exponent is significantly less than the 0.666 value expected from the law of similitude. Pelecanoides , with wings highly modified for diving, is an exception to the above trend. With increasing size the petrel wing becomes longer and narrower, aspect ratios increasing from about 6.5 in small storm petrels to about 15.6 in the giant albatrosses. Elongation is accompanied by changes in the proportions of the arm bones; the terminal segment, composed of the manus and primary feathers, becomes proportionately smaller and the inner segments, supported by the humerus and radio‐ulna, proportionately larger with increasing body size. Some ecological correlates of interspecific differences in wing loadings and shapes are discussed.