Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit
Emperor penguins leap from the water onto the sea ice. Their ability to reach above-water height depends critically on initial vertical speed of their leaping, assuming that the kinetic energy is converted to gravitational potential energy. We deliberately changed the above-water heights of ice hole...
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fthighwire:oai:open-archive.highwire.org:jexbio:208/13/2549 2023-05-15T13:47:25+02:00 Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit Sato, Katsufumi Ponganis, Paul J. Habara, Yoshiaki Naito, Yasuhiko 2005-07-01 00:00:00.0 text/html http://jeb.biologists.org/cgi/content/short/208/13/2549 https://doi.org/10.1242/jeb.01665 en eng Company of Biologists http://jeb.biologists.org/cgi/content/short/208/13/2549 http://dx.doi.org/10.1242/jeb.01665 Copyright (C) 2005, Company of Biologists Research Article TEXT 2005 fthighwire https://doi.org/10.1242/jeb.01665 2013-04-02T07:21:21Z Emperor penguins leap from the water onto the sea ice. Their ability to reach above-water height depends critically on initial vertical speed of their leaping, assuming that the kinetic energy is converted to gravitational potential energy. We deliberately changed the above-water heights of ice hole exits, in order to examine whether penguins adjusted swim speed in accordance with the above-water height of the ice. Penguins were maintained in a corral on the fast ice in Antarctica, and voluntarily dived through two artificial ice holes. Data loggers were deployed on the penguins to monitor under water behavior. Nine instrumented penguins performed 386 leaps from the holes during experiments. The maximum swim speeds within 1 s before the exits through the holes correlated significantly with the above-water height of the holes. Penguins adopted higher speed to exit through the higher holes than through the lower holes. Speeds of some failed exits were lower than the theoretical minimum values to reach a given height. Penguins failed to exit onto the sea ice in a total of 37 of the trials. There was no preference to use lower holes after they failed to exit through the higher holes. Rather, swim speed was increased for subsequent attempts after failed leaps. These data demonstrated that penguins apparently recognized the above-water height of holes and adopted speeds greater than the minimal vertical speeds to reach the exit height. It is likely, especially in the case of higher holes (>40 cm), that they chose minimum speeds to exit through the holes to avoid excess energy for swimming before leaping. However, some exceptionally high speeds were recorded when they directly exited onto the ice from lower depths. In those cases, birds could increase swim speed without strokes for the final seconds before exit and they only increased the steepness of their body angles as they surfaced, which indicates that the speed required for leaps by emperor penguins were aided by buoyancy, and that penguins can sometimes exit ... Text Antarc* Antarctica Emperor penguins Sea ice HighWire Press (Stanford University) Corral ENVELOPE(-62.950,-62.950,-64.900,-64.900) Journal of Experimental Biology 208 13 2549 2554 |
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HighWire Press (Stanford University) |
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fthighwire |
language |
English |
topic |
Research Article |
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Research Article Sato, Katsufumi Ponganis, Paul J. Habara, Yoshiaki Naito, Yasuhiko Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
topic_facet |
Research Article |
description |
Emperor penguins leap from the water onto the sea ice. Their ability to reach above-water height depends critically on initial vertical speed of their leaping, assuming that the kinetic energy is converted to gravitational potential energy. We deliberately changed the above-water heights of ice hole exits, in order to examine whether penguins adjusted swim speed in accordance with the above-water height of the ice. Penguins were maintained in a corral on the fast ice in Antarctica, and voluntarily dived through two artificial ice holes. Data loggers were deployed on the penguins to monitor under water behavior. Nine instrumented penguins performed 386 leaps from the holes during experiments. The maximum swim speeds within 1 s before the exits through the holes correlated significantly with the above-water height of the holes. Penguins adopted higher speed to exit through the higher holes than through the lower holes. Speeds of some failed exits were lower than the theoretical minimum values to reach a given height. Penguins failed to exit onto the sea ice in a total of 37 of the trials. There was no preference to use lower holes after they failed to exit through the higher holes. Rather, swim speed was increased for subsequent attempts after failed leaps. These data demonstrated that penguins apparently recognized the above-water height of holes and adopted speeds greater than the minimal vertical speeds to reach the exit height. It is likely, especially in the case of higher holes (>40 cm), that they chose minimum speeds to exit through the holes to avoid excess energy for swimming before leaping. However, some exceptionally high speeds were recorded when they directly exited onto the ice from lower depths. In those cases, birds could increase swim speed without strokes for the final seconds before exit and they only increased the steepness of their body angles as they surfaced, which indicates that the speed required for leaps by emperor penguins were aided by buoyancy, and that penguins can sometimes exit ... |
format |
Text |
author |
Sato, Katsufumi Ponganis, Paul J. Habara, Yoshiaki Naito, Yasuhiko |
author_facet |
Sato, Katsufumi Ponganis, Paul J. Habara, Yoshiaki Naito, Yasuhiko |
author_sort |
Sato, Katsufumi |
title |
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
title_short |
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
title_full |
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
title_fullStr |
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
title_full_unstemmed |
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
title_sort |
emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit |
publisher |
Company of Biologists |
publishDate |
2005 |
url |
http://jeb.biologists.org/cgi/content/short/208/13/2549 https://doi.org/10.1242/jeb.01665 |
long_lat |
ENVELOPE(-62.950,-62.950,-64.900,-64.900) |
geographic |
Corral |
geographic_facet |
Corral |
genre |
Antarc* Antarctica Emperor penguins Sea ice |
genre_facet |
Antarc* Antarctica Emperor penguins Sea ice |
op_relation |
http://jeb.biologists.org/cgi/content/short/208/13/2549 http://dx.doi.org/10.1242/jeb.01665 |
op_rights |
Copyright (C) 2005, Company of Biologists |
op_doi |
https://doi.org/10.1242/jeb.01665 |
container_title |
Journal of Experimental Biology |
container_volume |
208 |
container_issue |
13 |
container_start_page |
2549 |
op_container_end_page |
2554 |
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1766247093307965440 |