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Gottfried Sachs (Institute of Flight System Dynamics, Technische Universität München, Garching, Germany) and colleagues, writing in the Journal of Experimental Biology have used GPS loggers to study dynamic soaring in Wandering Albatrosses Diomedea exulans from the Kerguelen Islands in fine detail (click here).

The paper’s summary follows:

“Dynamic soaring is a small-scale flight manoeuvre which is the basis for the extreme flight performance of albatrosses and other large seabirds to travel huge distances in sustained non-flapping flight.  As experimental data with sufficient resolution of these small-scale movements are not available, knowledge is lacking about dynamic soaring and the physical mechanism of the energy gain of the bird from the wind.  With new in-house developments of GPS logging units for recording raw phase observations and of a dedicated mathematical method for postprocessing these measurements, it was possible to determine the small-scale flight manoeuvre with the required high precision.  Experimental results from tracking 16 wandering albatrosses (Diomedea exulans) in the southern Indian Ocean show the characteristic pattern of dynamic soaring.  This pattern consists of four flight phases comprising a windward climb, an upper curve, a leeward descent and a lower curve, which are continually repeated. I t is shown that the primary energy gain from the shear wind is attained in the upper curve where the bird changes the flight direction from windward to leeward. As a result, the upper curve is the characteristic flight phase of dynamic soaring for achieving the energy gain necessary for sustained non-flapping flight.”

Effortless flying: a Wandering Albatross at sea.

Photograph by John Chardine

Click here to read of a related paper on Wandering Albatross flight by Gottfried Sachs and colleagues.

Reference:

Sachs, G., Traugott, J., Nesterova, A.P. & Bonadonna, F. 2013.  Experimental verification of dynamic soaring in albatrosses.  Journal of Experimental Biology 216: 4222-4232.

John Cooper, ACAP Information Officer, 24 November 2013