How ‘vegan’ pandas rely on carnivore past

PANDAS can survive on a “vegan” diet because they still have the digestive system of a carnivore, a study suggests.

Giant pandas feed almost exclusively on highly fibrous bamboo, despite descending from primarily meat-eating carnivores.

Now the new research found the protein and carbohydrate content of the panda’s diet is similar to that of “hypercarnivores”, a class of meat-eating animals that derive 70 per cent or more of their food from eating other animals.

Published in Current Biology, the study described that while the panda’s jaw and head evolved to adapt to eating plants, its digestive tract, digestive enzymes, and gut microbes remain able to pummel food for as much nutrition as possible.

“As we know, the giant panda is a carnivora species, yet extremely specialised on a plant food, the bamboo,” said Fuwen Wei of the Chinese Academy of Sciences in Beijing, who authored the study.

“The transition was likely more superficial than assumed, combining substantial adaptation to new food types with relatively smaller changes in macronutrient handling.”

The scientists used an approach called nutritional geometry, which considers how mixtures of nutrients and other dietary components influence health and disease, to assess the macronutrient mix of the panda’s diet.

They say the findings can help resolve long-standing questions concerning giant panda evolution, including the unusual transition from carnivorous ancestry to extreme specialised herbivory.

“They are herbivores with respect to the foods they eat, but the macronutrient mix of the diet is more like carnivores,” explained Prof David Raubenheimer, from the University of Sydney, who also took part in the research.

Wild pandas, long an endangered species, were downgraded to “vulnerable” in 2016, due to conservation efforts that helped raise the population by 17 per cent in a decade. However, conservationists warn that their status remains imperilled, most pressingly as a result of climate change.

Last year the Chinese government announced it was to build a £1.1billion panda conservation area in Sichuan province.