Wave-slope soaring of the brown pelican

摘要

Some birds are able to fly with little flapping by exploiting energy present in the ambient wind-field [1–5]. When these energy gains are great enough to offset the cost of flight, the phenomenon is known as ‘soaring’ [1, 6]. As an energy efficient means of searching for prey or travelling long distances, soaring behaviors are widespread in avians and have demonstrated ecological significance [5, 7–9].