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First published online January 25, 2005
Journal of Experimental Biology 208, iii (2005)
Copyright © 2005 The Company of Biologists Limited
doi: 10.1242/jeb.01460

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Inside JEB

HOMEWARD BOUND

Yfke van Bergen

yfke{at}biologists.com

Homing pigeons' uncanny ability to navigate home depends on a dazzling array of cues, including the sun, smells and familiar landmarks. Pigeons appear to use both a topographical map of familiar landmarks and an internal compass bearing to navigate across familiar terrain. To assess the relative importance of the map and compass, Anna Gagliardo and colleagues from the University of Pisa decided to see what would happen if the birds' map information conflicted with their compass bearing (p. 469).

Pigeons use the sun as a compass, so to confuse the birds' orientation the team shifted pigeons' circadian rhythms by keeping the birds in an artificial light-dark cycle, resulting in clock-shifted pigeons. The birds' sun compass now indicated a wrong homeward direction but familiar landmarks could still indicate the true homeward direction. The team released normal and clock-shifted pigeons from familiar and unfamiliar sites and recorded the pigeons' orientation before they took off as well as the direction they disappeared in. At familiar release sites, the team saw that birds with normal circadian rhythms, which were able to use their sun compass, were homeward oriented even before take-off and flew off in the direction of home. But clock-shifted pigeons were randomly oriented before take-off and did not vanish in a homeward direction. Clearly, the sun compass strategy is important, but this was not the end of the story. Clock-shifted birds released from familiar sites showed a smaller deflection from the homeward orientation than clock-shifted birds released from unfamiliar sites. So while clock-shifting deflected the birds from the true direction of home, familiarity with the site reduced this deflection, presumably because the birds use familiar landmarks to ensure that they are homeward bound.

References

Gagliardo, A., Odetti, F. and Ioalè, P. (2005). Factors reducing the expected deflection in initial orientation in clock-shifted homing pigeons. J. Exp. Biol. 208,469 -478.[Abstract/Free Full Text]

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Related articles in JEB:

Factors reducing the expected deflection in initial orientation in clock-shifted homing pigeons

Anna Gagliardo, Francesca Odetti, and Paolo Ioalè
JEB 2005 208: 469-478. [Abstract] [Full Text]  

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by van Bergen, Y. Search for Related Content PubMed Articles by van Bergen, Y. Social Bookmarking                         What's this?