Research: How Do Bamboo-eating Red and Giant Pandas Coexist? main content.

Research: How Do Bamboo-eating Red and Giant Pandas Coexist?

by AMNH on


New research on the skulls of red pandas and giant pandas provides further explanation as to why the two species—which are not closely related but dine on the same food, bamboo, in the same geographic area—are able to coexist.

Red panda
Like giant pandas, red pandas (Ailurus fulgens) are members of the order Carnivora, but unlike giant pandas they are most closely related to raccoons and weasels—and weigh only about 10 pounds. Giant pandas are in the bear family and weigh up to 220 pounds. 
Via Wikimedia Commons/Brunswyk

Using high-resolution imaging and biting simulations, scientists at the American Museum of Natural History and the University of Málaga in Spain found that the skulls of the two panda species not only are distantly related but also have structural differences related to the way the animals chew. These substantial differences reflect distinct bamboo feeding preferences, with red pandas foraging on softer parts of the plant and giant pandas seeking out the tougher stems. The findings are published in the journal Biology Letters.

“Scientists have been studying the differences between red pandas and giant pandas for a long time because there’s a basic principle in ecology that says if two species of an organism utilize the same resources, they cannot live in the same space. There’s too much competition,” said Z. Jack Tseng, a Frick Postdoctoral Fellow in the Museum’s Division of Paleontology and the corresponding author on the new study. “This research contributes to the body of work showing how the pandas co-exist. We’ve found that fundamentally, based on the structure of their skulls, they cannot eat the same things.”

A computer generated image of two skulls, one of a Giant Panda, one of a Red Panda. The Red Panda skull shows a higher level of chewing stress when biting with the right canine tooth.
These computer-generated cranium models simulate the stresses generated when a giant panda (left) and red panda (right) bite down on something at the right canine tooth. The colors represent stress magnitudes and distribution, with dark blue signifying the animal’s jaw at rest and red representing the highest chewing stress. 

The red (Ailurus fulgens) and giant (Ailuropoda melanoleuca) pandas are both from the mammalian order Carnivora, but they are separated from each other by about 40 million years of evolution. The red panda is most closely related to animals like raccoons and weasels and weighs about 10 pounds. The giant panda is a member of the bear family, and it is much larger, weighing about 220 pounds. Their geographic ranges overlap in southern China, and both animals have independently adapted to a diet consisting mainly of the same bamboo species.

Giant Panda Wang Wang
The giant panda (Ailuropoda melanoleuca) Wang Wang, who lives at the Adelaide (Australia) Zoo
Via Wikimedia Commons/Manyman

The researchers used X-ray computed tomography (CT) to create high-resolution, three-dimensional models of the pandas’ skulls and teeth. Based on these data, they built a series of computer-generated biting simulations to study the skulls’ biomechanics. They found that although the skulls have some broad similarities—they both are robust and versatile and can accommodate a wide variety of chewing—there are some distinct differences.

The skull of the red panda is better at distributing mechanical stress during chewing than the skull of the giant panda. But the giant panda has a stronger skull that can withstand greater forces that are more concentrated and could be more damaging, even after accounting for the size differences between the two species.

“These differences tie into the way that the species actually process bamboo,” Tseng said. “The giant panda is a less-refined eater: it does a lot of chomping and swallowing. Their skulls are stronger overall, so the peak biting stresses are lower, meaning that they can eat harder and larger pieces of bamboo. The red panda has a weaker skull but it’s better at distributing stresses, allowing it to chew longer and break down soft bamboo leaves more thoroughly before they swallow them.”

These links between dietary preference and skull performance provide an engineering basis for explaining how the co-existence of the two panda species is possible, the authors say.

For more information about this study, read the Museum’s press release.