Optic flow cues guide flight in birds

Partha S Bhagavatula, Charles Claudianos, Michael Robert Ibbotson, Mandyam Veerambudi Srinivasan

Research output: Contribution to journalArticleResearchpeer-review

68 Citations (Scopus)

Abstract

Although considerable effort has been devoted to investigating how birds migrate over large distances, surprisingly little is known about how they tackle so successfully the moment-to-moment challenges of rapid flight through cluttered environments [1]. It has been suggested that birds detect and avoid obstacles [2] and control landing maneuvers [3-5] by using cues derived from the image motion that is generated in the eyes during flight. Here we investigate the ability of budgerigars to fly through narrow passages in a collision-free manner, by filming their trajectories during flight in a corridor where the walls are decorated with various visual patterns. The results demonstrate, unequivocally and for the first time, that birds negotiate narrow gaps safely by balancing the speeds of image motion that are experienced by the two eyes and that the speed of flight is regulated by monitoring the speed of image motion that is experienced by the two eyes. These findings have close parallels with those previously reported for flying insects [6-13], suggesting that some principles of visual guidance may be shared by all diurnal, flying animals.
Original languageEnglish
Pages (from-to)1794 - 1799
Number of pages6
JournalCurrent Biology
Volume21
Issue number21
DOIs
Publication statusPublished - 2011

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