TY  - STD
AU  - Groscolas R, Viera V.
PY  - 2010//
TI  - Heart rate as a predictor of energy expenditure in undisturbed fasting and incubating penguins.
T2  - J. Exp. Biol.
BT  - The Journal of experimental biology
SP  - 153 -60
VL  - 213
IS  - 1
KW  - Animals
KW  - Energy Metabolism
KW  - Fasting
KW  - Fasting: physiology
KW  - Female
KW  - Heart Rate
KW  - Male
KW  - Nesting Behavior
KW  - Nesting Behavior: physiology
KW  - Spheniscidae
KW  - Spheniscidae: physiology
KW  -
N2  - Heart rate (f(H)) measurement offers the possibility to monitor energy expenditure (EE) in wild animals if the EE/f(H) relationship for the species, physiological stages and activities of interest is known. This relationship has been extensively studied using oxygen consumption rate ( ) measurement in captive, repeatedly handled king penguins (Aptenodytes patagonicus). Unfortunately, the potential effects of stress on the observed relationships resulting from handling and confinement were not considered. This study is the first involving undisturbed animals, and determines the EE/f(H) relationship in naturally fasting and freely incubating or captivity-acclimatized male and female king penguins. EE determination was based on (1) the measurement of body mass loss during periods of phase II fasting, and (2) the calculation of its energy equivalent from changes in body composition, i.e. 23.9 kJ g(-1). f(H) levels in freely incubating and captivity-acclimatized birds were found to be 50-70% lower than those previously reported for resting king penguins during measurements. Significant EE/f(H) relationships were found in freely incubating and captive males and females (R(2)=0.59 to 0.84), with no difference observed between genders. The best overall relationship was obtained by including fasting duration (t, days) in the model: EE=818+43.7xf(H)+36.3t-1.4txf(H) (R(2)=0.91). This equation yielded EE estimates approximately 26% higher than the previously reported 'best' predictive equation in king penguins, and even more so when f(H) was low. This result suggests that stress induces a disproportionate increase of f(H) vs O(2) consumption, and that the use of EE/f(H) relationships obtained in stressed birds could lead to underestimated EE values.
SN  - 0022-0949
UR  - http://dx.doi.org/10.1242/jeb.033720
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=71), last updated on Tue, 30 Nov 1999 00:00:00 +0100
ID  - GroscolasR2010
ER  -