The Flight of Petrels and Albatrosses (Procellariiformes), Observed in South Georgia and its Vicinity

摘要: Nine procellariiform species, covering a range of body mass exceeding 200: 1, were studied during visit to Bird Island, South Georgia, with the British Antarctic Survey, in 1979-1980 field season. Speed measurements made by ornithodolite birds slope-soaring over land, flying sea but observed from and ship. In second group, which showed least anomalies, lift coefficients corresponding mean airspeeds about 1 for albatrosses, decreasing 0.3 smallest petrels. All species increased speed when against wind. The small proceeded flap-gliding, while large ones flapped infrequently, only light winds. flew lower than larger ones, this may be related fact that most observations into albatrosses ( Diomedea, Phoebetria ) giant petrels Macronectes found have ‘shoulder lock’, consisting tendon sheet associated pectoralis muscle, restrained wing elevation above horizontal. This arrangement was not seen smaller interpreted as an adaptation reducing energy cost gliding flight. main soaring method appeared along waves. Windward ‘pullups’ suggestive classical ‘dynamic soaring’ technique medium-sized species. However, calculated strength wind gradient would been insufficient maintain airspeed heights observed, it concluded pullups must come kinetic energy, acquired wave slope lift. Gliding downwind through should significantly increase glide ratio, observed. Slope-soaring moving waves zero recorded. data used derive estimates average speeds different able on foraging expeditions. Estimates rate consumption also made, taking account greater dependence flapping ones. distance travelled consuming fuel equivalent given fraction seem very strongly dependent mass. Comparison largest Diomedea exulans Oceanites oceanicus suggests ‘range’, defined way, varies 0.60 power mass, although relation is more complex simple function.