Editing Dynamic soaring (section)

==Birds==
[[Image:Phoebastria irrorata flying.jpg|upright|thumb|right|Waved albatross ''Phoebastria irrorata'']]
<!-- Some [[seabird]]s have been observed performing dynamic soaring over flat land, so the technique does not inherently depend on ocean waves. But the presence of waves can have two benefits. First, the velocity gradient can be enhanced by the presence of waves, just as it is enhanced by hills and other terrain features on land. Second, the bird can mix dynamic soaring with [[slope soaring]] to extract more energy.  << Why should dynamic soaring depend on waves? Why should slope soaring be more common on sea than on land? -->

[[Albatross]]es are particularly adept at exploiting these techniques and can travel thousands of miles using very little energy. [[Gull]]s and [[tern]]s also exhibit this behaviour in flight. Birds that soar dynamically have a skeletal structure that allows them to lock their wings when they are soaring, to reduce muscle tension and effort.

[[Lord Rayleigh]] first described dynamic soaring in 1883 in the British journal ''[[Nature (journal)|Nature]]'':<ref>Lord Rayleigh (5 April 1883) [https://books.google.com/books?id=2qDvAAAAMAAJ&pg=PA194 "The soaring of birds,"] ''Nature'', vol. 27, no. 701, pages 534–535.</ref>

:...a bird without working his wings cannot, either in still air or in a uniform horizontal wind, maintain his level indefinitely. For a short time such maintenance is possible at the expense of an initial relative velocity, but this must soon be exhausted. Whenever therefore a bird pursues his course for some time without working his wings, we must conclude either
:#that the course is not horizontal,
:#that the wind is not horizontal, or
:#that the wind is not uniform.
:It is probable that the truth is usually represented by (1) or (2); but the question I wish to raise is whether the cause suggested by (3) may not sometimes come into operation.

The first case described above by Rayleigh is simple gliding flight, the second is static soaring (using [[thermal]]s, [[lee waves]] or [[slope soaring]]), and the last is dynamic soaring.<ref>{{Cite journal |last=Boslough, Mark B.E. |date=June 2002 |title=Autonomous Dynamic Soaring Platform for Distributed Mobile Sensor Arrays |url=http://www.cs.sandia.gov/web1433/pubsagent/MobileSensorArrays.pdf |url-status=dead |journal=Sand Report |publisher=Sandia National Laboratories, Albuquerque, New Mexico |id=SAND2002-1896 |archiveurl=https://web.archive.org/web/20060923223206/http://www.cs.sandia.gov/web1433/pubsagent/MobileSensorArrays.pdf |archivedate=2006-09-23}}</ref>