HEART-RATE AND OXYGEN-CONSUMPTION OF EXERCISING GENTOO PENGUINS

Heart rate (f(H)) and oxygen consumption (V-O2) were recorded from gen too penguins walking on a variable-speed treadmill. After an initial i ncrease, f(H) and V-O2 increased linearly with walking speed A curvili near regression equation best described the relationship between f(H) and V-O2. Over a 3-d period, f(H) and V-O2 were recorded continuously from six gentoo penguins that had been injected with doubly, labeled w ater (DLW). When f(H) was used to predict V-O2 over the 3 d, the estim ate was not significantly, different from the measured V-O2 With an er ror (-1.0%) that was less than that produced by the DLW method (+1.6%) . The estimate produced by the f(H) technique was also accurate when a pplied both to shorter periods (30 min) and to periods of activity and inactivity. Seven gentoo penguins were also swum in a water channel, and f(H) and V-O2 were again recorded The relationship between f(H) an d V-O2 determined from the birds in the water channel was not signific antly, different from that obtained from the walking birds. It is seem s reasonable that, since the f(H)-V-O2 relationship of most behaviors of the penguin have been determined while the animal is walking and sw imming, f(H) can be used to predict the metabolic rate of free-ranging animals.