Why are pandas black and white? Biologists now have a new theory
MAMMALS are a mostly drab bunch. Due to camouflage, a nocturnal lifestyle and other evolutionary demands, dull and earthy tones reign supreme. There are a few notable exceptions. When mandrills become excited, the monkeys’ rumps turn shades of ruby and bright blue, an effect not unlike melted crayon wax.
But bears, by and large, stick to the muted program. Even North American black bears, whose name belies their true variations, keep to blacks or brown shades, with a just a handful of those bears sporting dirty white or blueish-grey coats. Then there is the panda bear. Though pandas keep to stark blacks and whites, their patterns are famous. Their iconic image has served as an Olympic mascot and as an international symbol of conservation. In addition, their markings were the inspiration behind a catchy rap jingle.
But simply because something was ubiquitous did not mean it was well-understood.
Why, for example, are pandas black and white? The authors of a new study on the panda think they might have the answer: Panda patterns serve as a combination of communication and camouflage, a group of biologists wrote recently in the journal Behavioural Ecology.
The purpose of the pandas’ black limbs, black ears, black eye patches and white bodies was a particular curiosity to these scientists at the University of California at Davis and California State University at Long Beach.
“Understanding why the giant panda has such striking colouration has been a long-standing problem in biology that has been difficult to tackle because virtually no other mammal has this appearance, making analogies difficult,” Tim Caro, a biologist in Wildlife, Fish and Conservation Biology department on the Davis campus, said in a news release.
Caro knows a bit about animal colour. He made a compelling case that zebras evolved stripes as a defence against biting flies in a book published in December, and has also investigated the colours of skunks and coconut crabs.
The biologists reached their conclusion by combing through photographs of many different animal coats, representing 195 other land-dwelling carnivores as well as nearly 40 different types of bears. They isolated fur colours over different parts of the body: back, legs, ears and head, and also divided the animals’ faces into separate regions.
“The breakthrough in the study was treating each part of the body as an independent area,” Caro said. — Washington Post