Key points are not available for this paper at this time.
Colin J. Pennycuick, Fifteen Testable Predictions about Bird Flight, Oikos, Vol. 30, No. 2, Current Bird Migration Research. Proceedings of a Symposium at Falsterbo, Sweden, 3-8 October, 1977 (1978), pp. 165-176
C. J. Pennycuick (1978) studied this question.