When we think of a panda, we think of a round, fluffy, caricature of a bear. We think white head, black ears and eye patches, white torso with black shoulders and limbs, and a round-tailed tushy. The giant panda (Ailuropoda melanoleuca) is a species of bear — one of eight bear species worldwide. Pandas are endemic to bamboo forests in China, though they can be found in international zoos on lease. ‘Panda diplomacy’ has been practised in China since the 7th century, with pandas being gifted as symbols of good international relations, but this has since transformed into a lucrative business for China, with countries paying up to £1,000,000 annually to keep pandas in their zoos. As well as being political influencers, pandas are the subject of many critically acclaimed films and viral videos. They are emblems of Chinese culture. They are the face of the massive non-profit conservation organisation, WWF. Their charisma and iconicity knows no bounds. Yet, for the longest time, scientists have been baffled by the panda’s appearance.

Why is the panda black and white? Moreover, why is the panda specifically black in some parts, and white in other parts? Several hypotheses have been posed. The patterning could be some sort of display, and signal ferocity to others. Or, the pattern could provide thermoregulatory benefits. Alternatively, since dark eye patches have been found to reduce glare from the sun in other species, pandas may have their distinctive facial marking for a similar reason. Others have proposed that pandas are patterned the way they are for camouflage. Until recently, these speculations were on similar footing in terms of their empirical support. But as scientific rigour and technological advancements developed, research has been honing in on why giant pandas evolved their distinct fur.

In 2017, researchers collected 10 photographs of the fur of 197 terrestrial carnivore species (including the panda) and 39 ursid subspecies. They then developed a periodic table of colour grades, and categorised the colouration of fur from each region of the body, for all species and subspecies. Fur colouration for each animal was then examined against temperature, habitat background, and social variables, to test hypotheses about whether the panda’s pelage evolved for thermoregulation, crypsis, or social signalling. Results for lacked support for all but one hypothesis: crypsis. There seemed to be a strong correlation between non-hibernating ursid species having lighter fur coloration and snow prevalence. Pandas do not hibernate, and are active during winter periods when there is snowfall — suggesting that a panda’s white fur could plausibly act as camouflage against a snowy background. As for the darker fur, researchers speculate that this may serve a similar function of background matching, for shaded areas of the bamboo forest, outside of the snowy winter season.

A later study in 2021 went one step further in understanding panda patterning. By using image analysis to simulate feline, canine, and human vision of various photographs of pandas in captive and wild settings, it was found that though these strikingly patterned, colossal furballs were very prominent to the eye in captivity, pandas can evade the detection of predators in their natural habitat. By simulating what potential predators could see, and quantifying how closely panda fur blends into the background through the eyes of said beholders, it was verified that the different regions of a panda’s coat do blend in with various elements of their wild habitat — and further, that the patterning of the colouration acts as outline disruption, so in any given background a whole panda silhouette cannot be discerned. Black fur breaks up the body outline and conforms with dark shadows. White fur seamlessly morphs into snowy landscapes. Intermediate brownish fur matches well with the earthy ground. The background matching capacities of pandas were also compared against other known camouflaging species. The finding was that pandas fall snuggly within this cryptic spectrum, and are no more conspicuous than the next cryptic species.

Though, this is not to say that the only function a panda’s fur confers is crypsis. It may well be that crypsis was the main evolutionary driver of a panda’s fur patterning, but the subsequent adaptation may have been coopted for other usages. For example, a study in 2008 found that pandas can discriminate between eye patch shapes, suggesting individuals may be able to distinguish each other, based on their variation in facial patterning. Nonetheless, uncovering an explanation for the panda’s appearance has important implications for how we go on to protect this threatened species. Pandas seem to be adapted to hide well in wild habitats, but how will this change with increasing deforestation and human influence? What consequences will heightened conspicuousness have on already dwindling populations?

What can be said is that the situation is a little ironic. What makes a panda so charismatic and iconic, what makes it so politically influential, what makes it garner public adoration, was found to be a mode of visual detection avoidance. The high-contrast fur patterning we have all come to know and love can act as a multi-setting camouflage, keeping wild pandas hidden from plain sight. More research is necessary for understanding how this knowledge can be applied to conservation, but perhaps a way to protect the longevity of this species is to ensure that they can remain undetected by threats, within their natural habitats.

Mentioned papers:

Why is the giant panda black and white? | Behavioral Ecology | Oxford Academic (oup.com)

The giant panda is cryptic | Scientific Reports (nature.com)

Discrimination of face-like patterns in the giant panda (Ailuropoda melanoleuca). (apa.org)

Featured image taken from Caro et al. (2017)’s published paper, cited below.