The giant panda is undoubtedly one of the world’s most iconic and beloved animals. Just ask the thousands of people who line up to catch a glimpse of new panda arrivals at zoos around the world.
At least some of the panda’s appeal comes down to its long list of idiosyncrasies, from their seeming reluctance to mate to the utter helplessness of panda cubs at birth (they are born hairless, blind, and roughly the size of a stick of butter).
Another peculiarity is the giant panda’s highly specific diet. Everyone knows that pandas love bamboo, but the extent of their reliance on this plant is hard to overstate. Bamboo makes up roughly 99% of the giant panda’s diet, and the bears spend up to 16 hours a day eating shoots, leaves, and stems in order to get the calories they need to survive. As adults, pandas excel at identifying the freshest and most nutritious plants, an essential skill, as only a fraction of what they consume is actually digested. Because of this, pandas typically eat around 15 percent of their body weight in bamboo every day.
Surprisingly, the giant panda’s digestive system resembles a carnivore’s much more than an herbivore’s. Though far less omnivorous than other bears, pandas will (very) occasionally branch out from bamboo and eat other plants or even fish or small mammals. A prime example of environmental factors driving evolution, pandas adapted over time to the abundance and reliability of bamboo in their habitat. Though not as nutritious as some other potential food sources, including meat, bamboo is readily available in the mountains of southwestern China, and pandas don’t have to compete with other species for it.
Pandas have a very low metabolic rate and expend little energy on their daily activities. Coupled with the amount of time they spend foraging and eating, this allows them to survive on a bamboo diet.
Puzzling pandas:
- The giant panda’s natural habitat is confined to a small area of dense bamboo forests in the mountains of the Sichuan, Shaanxi, and Gansu provinces. The population of giant pandas in the wild is roughly 1,800 individuals.
- Thanks to broad, flat molars that are ideal for crushing, giant pandas can eat bamboo stems up to an inch and a half in diameter. They have also evolved a pseudo-thumb that makes it easier to grip bamboo plants.
- In a study published earlier this year, Chinese researchers focused on the presence of microRNA (miRNA) in the panda’s bamboo-heavy diet. This genetic material is involved in regulating gene expression, dopamine pathways, growth, immune responses, behavior, and physiological processes like smell and taste. Essentially, as pandas continue to eat bamboo, the miRNA molecules influence their feeding habits, ensuring that they maintain their mostly plant-based diet.
