In A Nutshell
Despite some confusion, tests have proven that the giant panda is genetically a bear. It also has a carnivore’s digestive system, designed for eating meat. However, in the wild, the panda feeds almost exclusively on bamboo. It gets by mainly by eating bamboo in huge amounts and conserving its energy, because that carnivore’s gut pulls surprisingly little nutrition out of the plant.
The Whole Bushel
Especially adorable, pandas are among the world’s most beloved creatures. Although known in their native China since antiquity, the panda has only been known in the West since 1869, when a French missionary sent a specimen back to Paris. They have been the subject of much taxonomic confusion over the decades since, as they share traits of both bears and members of the raccoon family. However, advances in molecular genetics have determined that it is indeed a member of the Ursidae, or bear family.
Herbivorous mammals such as cows and deer have long, complicated digestive systems with which to draw the energy from plant material. The panda’s digestive system is short, like those of other carnivores, and it never evolved the genes or the gut bacteria that true plant eaters depend on. How then is it able to survive on bamboo, a type of grass? Mostly by eating an enormous amount of it. A panda can spend up to 14 hours a day feeding on roughly 12.5 kilograms (27.5 pounds) of bamboo and still digest only about 17 percent of what it takes in. Earlier research did find some microbes in panda droppings that can attack cellulose, and scientists looked at them as a possible route to better biofuels. But a larger 2015 study found the panda’s gut bacteria actually resemble those of a meat eater. They are dominated by species that thrive on protein, and they lack the fibre fermenters a cow relies on.
Precisely how and why the panda evolved in this fashion is still debated. One of the more plausible theories is that the panda once maintained a variegated diet like other bears, but competition with more fearsome predators like tigers, leopards, and Asiatic black bears drove it into the remote mountains, where it was left to subsist on bamboo. That switch to a near total bamboo diet happened roughly two million years ago. Along the way the panda picked up a few herbivore traits, including an enlarged wrist bone that works as a sixth “thumb” for gripping bamboo, and it lost the ability to taste umami, the savory flavor tied to meat. The old idea that only a handful of pandas remain no longer holds, though. Decades of conservation work paid off, and in 2016 the species was moved off the endangered list and reclassified as vulnerable, with 1,864 counted in the wild in China’s 2014 national census.
Ed.: We’d like to clarify that the featured quote is, in fact, a joke from O’Doherty’s humorous book of fake panda facts.
Show Me The Proof
How Do Pandas Survive on Bamboo?
Guardian: Pandas Poorly Adapted for Digesting Bamboo
University of Sydney: For Giant Pandas, Bamboo Is Vegetarian ‘Meat’
Smithsonian: Could Panda Poop Be the Secret to More Efficient Biofuel?
Discovery: The Giant Panda Debate — Bear or Raccoon?
NatGeo: Giant Pandas
