Rhynchokinesis 4242494 100534295 2007-01-13T22:58:14Z SmackBot 433328 Date/fix the maintenance tags using [[Project:AWB|AWB]] '''Rhynchokinesis''' is an ability possessed by some [[bird]]s to flex their [[upper mandible]]. Rhynchokinesis is one of two types of [[cranial kinesis]], the other being [[prokinesis]], in which the upper mandible moves at the point where it is [[hinge]]d with the bird's [[skull]]. Rhynchokinesis on the other hand involves flexing at a point some way along the mandible - either upwards, in which case the upper and [[lower mandible]]s diverge, resembling a [[yawn]], or downwards, in which case the tips of the mandibles remain together while a gap opens up between them at their midpoint. Unlike prokinesis, which is widespread in birds, rhynchokinesis is only known in [[crane (bird)|crane]]s, [[shorebird]]s, [[swift]]s and [[hummingbird]]s. Species in which this has been recorded photographically include the following species: [[Short-billed Dowitcher]], [[Marbled Godwit]], [[Least Sandpiper]], [[Common Snipe]], [[Long-billed Curlew]], [[Pectoral Sandpiper]], [[Semipalmated Sandpiper]], [[Eurasian Oystercatcher]] and [[Bar-tailed Godwit]] (see Chandler 2002 and external links). ==External links== Photographs of birds performing rhynchokinesis can be found here: * [http://birdcentral.net/SBdowitcher1B.jpg] - a [[Short-billed Dowitcher]] * [http://www.photos-of-the-year.com/image/nature/632/3593open_beak_godwit-med.jpg] - a [[Marbled Godwit]] * [http://www.birdforum.net/attachment.php?s=30bab082f6b003975d2f1fcf23344ee1&attachmentid=10972] - a [[Least Sandpiper]] ==References== * ''A functional and evolutionary analysis of rhynchokinesis in birds'' by Richard L Zusi, Smithsonian Institution Press, 1984. * Chandler, Richard (2002) PhotoSpot - Rhynchokinesis in waders ''[[British Birds (magazine)|British Birds]]'' Vol 95 p395 {{Expand|date=January 2007}} [[Category:Ornithology]]