Summary
Fifty-four skeins of pink-footed geese (Anser brachyrhynchus) were photographed from directly underneath to eliminate the effects of perspective distortion, and the wingtip spacings (the distance between adjacent birds ’ wing tips perpendicular to the flight path at maximum wingspan) and depths (the...
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1994
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.320.1449 2023-05-15T13:29:57+02:00 Summary C. J. Cutts J. R. Speakman The Pennsylvania State University CiteSeerX Archives 1994 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.320.1449 http://jeb.biologists.org/content/189/1/251.full.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.320.1449 http://jeb.biologists.org/content/189/1/251.full.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://jeb.biologists.org/content/189/1/251.full.pdf text 1994 ftciteseerx 2016-09-04T00:18:00Z Fifty-four skeins of pink-footed geese (Anser brachyrhynchus) were photographed from directly underneath to eliminate the effects of perspective distortion, and the wingtip spacings (the distance between adjacent birds ’ wing tips perpendicular to the flight path at maximum wingspan) and depths (the distance between adjacent birds ’ body centres parallel to the flight path) were measured at the same time as local wind speeds. The photographs were used to test for savings in induced power from wing positioning relative to the predicted positions of vortices generated by other wings, using a theoretical model. The mean wing-tip spacing corresponded to a saving in induced power of 14 %, less than one-third of the maximum possible. The saving in total power might be as low as 2.4 %. The high variation in wing-tip spacing suggests that pink-footed geese found difficulty maintaining position and thus adopted a strategy of flying outboard of the optimal position that maximises savings. This may minimise the risk of straying into a zone where savings are negative. There was a significant correlation between depth and wing-tip spacing, supporting an alternative communication hypothesis, whereby the birds position themselves to obtain maximum information on their neighbour’s position. In high winds, there was little change in wing-tip spacing variation but a decrease in depth variation, suggesting a shift towards more regularly spaced skeins. Text Anser brachyrhynchus Unknown |
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Open Polar |
collection |
Unknown |
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ftciteseerx |
language |
English |
description |
Fifty-four skeins of pink-footed geese (Anser brachyrhynchus) were photographed from directly underneath to eliminate the effects of perspective distortion, and the wingtip spacings (the distance between adjacent birds ’ wing tips perpendicular to the flight path at maximum wingspan) and depths (the distance between adjacent birds ’ body centres parallel to the flight path) were measured at the same time as local wind speeds. The photographs were used to test for savings in induced power from wing positioning relative to the predicted positions of vortices generated by other wings, using a theoretical model. The mean wing-tip spacing corresponded to a saving in induced power of 14 %, less than one-third of the maximum possible. The saving in total power might be as low as 2.4 %. The high variation in wing-tip spacing suggests that pink-footed geese found difficulty maintaining position and thus adopted a strategy of flying outboard of the optimal position that maximises savings. This may minimise the risk of straying into a zone where savings are negative. There was a significant correlation between depth and wing-tip spacing, supporting an alternative communication hypothesis, whereby the birds position themselves to obtain maximum information on their neighbour’s position. In high winds, there was little change in wing-tip spacing variation but a decrease in depth variation, suggesting a shift towards more regularly spaced skeins. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
C. J. Cutts J. R. Speakman |
spellingShingle |
C. J. Cutts J. R. Speakman Summary |
author_facet |
C. J. Cutts J. R. Speakman |
author_sort |
C. J. Cutts |
title |
Summary |
title_short |
Summary |
title_full |
Summary |
title_fullStr |
Summary |
title_full_unstemmed |
Summary |
title_sort |
summary |
publishDate |
1994 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.320.1449 http://jeb.biologists.org/content/189/1/251.full.pdf |
genre |
Anser brachyrhynchus |
genre_facet |
Anser brachyrhynchus |
op_source |
http://jeb.biologists.org/content/189/1/251.full.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.320.1449 http://jeb.biologists.org/content/189/1/251.full.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766004476111486976 |