spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online December 14, 2007
Journal of Experimental Biology 211, 1-8 (2008)
Published by The Company of Biologists 2008
doi: 10.1242/jeb.005785
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JEB
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gilbert, C.
Right arrow Articles by Ancel, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gilbert, C.
Right arrow Articles by Ancel, A.

Energy saving processes in huddling emperor penguins: from experiments to theory

Caroline Gilbert*, Stéphane Blanc, Yvon Le Maho and André Ancel

IPHC-DEPE, UMR 7178; Centre National de la Recherche Scientifique, Université Louis Pasteur, 23 rue Becquerel, 67087 Strasbourg, France


Figure 1
View larger version (11K):
[in this window]
[in a new window]

  		Fig. 1. Thermoregulatory status of the three bird categories investigated (isolated, loosely grouped, free-ranging), and associated processes of energetic benefits. Values are mean rectal temperatures ± s.d. (see Prévost, 1961Go; Prévost and Sapin-Jaloustre, 1964Go; Mougin, 1966Go).

 

Figure 2
View larger version (13K):
[in this window]
[in a new window]

  		Fig. 2. Daily body mass losses and derived metabolic rates of isolated, loosely grouped and free-ranging male emperor penguins during winter (April to July). Mean daily body mass losses were calculated from published studies (Prévost, 1961Go; Prévost and Sapin-Jaloustre, 1964Go; Ancel et al., 1997Go). Estimated mean metabolic rates were calculated from the mean daily body mass loss applying Groscolas's method (Groscolas, 1988Go) and Ancel et al.'s results (Ancel et al., 1997Go).

 

Figure 3
View larger version (17K):
[in this window]
[in a new window]

  		Fig. 3. Summary of microclimatic conditions experienced by isolated, loosely grouped and free-ranging birds, and associated benefits.

 

Figure 4
View larger version (78K):
[in this window]
[in a new window]

  		Fig. 4. Picture of incubating birds huddling tightly during a blizzard. Note the reduction in body surface area exposed to the cold for birds inside the huddling group, and the snow on the surfaces still exposed to cold.

 

Figure 5
View larger version (7K):
[in this window]
[in a new window]

  		Fig. 5. Mass specific metabolic rate (sMR, W kg–1) of emperor penguins plotted as a function of body temperature (Tb, °C). The relationship was best described by the linear regression: sMR=–9.937+0.312Tb (r2=0.9973, P=0.033). (Data from Le Maho et al., 1976Go; Pinshow et al., 1976Go; Dewasmes et al., 1980Go; Gilbert et al., 2007Go).

 




© The Company of Biologists Ltd 2008