The energetics of barnacle geese (Branta leucopsis) flying in captive and wild conditions.
Experimental data on the relationship between mean heart rate (f(H)) and mean rate of oxygen consumption (VO(2)) of captive barnacle geese during flights in a wind tunnel are assessed in terms of their capacity to predict the typical VO(2) of wild barnacle geese, based on the recordings of their f(H), while undertaking autumn migratory flights between Spitsbergen (78 degrees N) and Caerlaverock, Scotland (55 degrees N). A significant linear relationship has been demonstrated between the f(H) and simultaneously recorded VO(2) of a single barnacle goose (B-B) flying in the wind tunnel (VO(2)=1.42 f(H)-304, r(2)=0.82, P<0.001, N=12 flights). Data recorded from three additional geese (N=4 flights), lay within the 95% prediction intervals of the relationship for goose B-B. When these geese (mean body mass=2.06 kg, n=4) were flown in the wind tunnel (WT) without the mask, they had a mean f(H) of 451+/-23 beats min(-1), yielding an estimate for VO(2) of 336+/-33 ml min(-1). However, f(H) has also been recorded from wild barnacle geese (mean migratory f(H) of 253 beats min(-1)), and substitution of this value into the above calibration equation results in an unrealistically low value for mean migratory VO(2) of only 55 ml min(-1). Various factors, such as differences in heart mass, selective tissue perfusion, environmental temperature and flock formation, which might account for some of the difference in f(H) between the captive and wild geese are discussed. Comparison with other WT studies shows that inter-species minimum mass-specific VO(2) declines with increasing body mass (M(b); range 0.035-2.8 kg) as 173 M(b)(-0.224), r(2)=0.848.
School of Biological Sciences, University of Wales Bangor, Bangor LL57 2UW, UK. c.bishop@bangor.ac.uk
C M
CM
Bishop
S
S
Ward
A J
AJ
Woakes
P J
PJ
Butler
D000818:Animals; D000835:Animals, Wild / Q000502:physiology; D002302:Cardiac Output; D004734:Energy Metabolism; D005426:Flight, Animal / Q000502:physiology; D005777:Geese / Q000502:physiology*; D006339:Heart Rate; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D012606:Scotland; D014919:Wind