The Metabolic Rates of Giant Panda and Red Panda

The giant panda (Ailuropoda melanoleuca) is one of the most endangered vertebrates and an iconic symbol of conservation. While progress has been made in understanding its genome, landscape ecology and anthropogenic effects on its populations, many aspects of its biology are unknown. I measured resting metabolic rate of the giant panda and compared it to metabolic rates of other large mammals. The giant panda has a thermal neutral zone that ranges from at least 9 to 26 °C. Its metabolic rate is 6.0% to 44.3% below that predicted by regressions of mass vs. metabolic rate in the literature and that may be due to its strictly herbivorous bamboo diet. These results raise questions about the universal predictive power of physiological relationships such as the metabolic theory of ecology that attempt to predict ecological relationships based on metabolism and body size without considering other variables. For these predictions to be useful and truly reflective of the study animal, basic metabolic data are needed on more large mammals and animals with varied diets, before reliable predictive theories can be formulated. I also measured the field metabolic rate of giant panda. The results showed that FMR varied between individuals despite the active time for each individual being very similar. The water-loop of the giant panda is much faster than predicted. The mean daily energy expenditure (DEE) was 21,592 KJ, (SD = 13,323) per day. That means there is enough bamboo in 1 km2 of the Wolong Reserve to provide food for 81,726 panda days. I measured the resting metabolic rate of red panda as well. There was no difference in metabolic rate between male and female red pandas. The RMR of red panda was higher in the winter than in the summer. McNab measured 2 red pandas in 1987 and found a very low metabolic rate, 0.153 ml/g/h. In my 17 red panda experiments, 0.204 ml/g/h was the lowest value that I measured. The average in summer (0.290 ml/g/h) was twice as high as McNab's mean. The red panda has a higher metabolic rate than previously measured.