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Evo­lu­tion


A Col­lec­tion of News by Moos

201705Mar20:01

Why giant pan­das are black and white

Infor­ma­tion
pub­lished 05 March 2017 | mod­i­fied 05 March 2017
archived

Giant panda in Madrid ZooThe sci­en­tists who uncov­ered why zebras have black-​and-​white stripes (to repel bit­ing flies), took the coloura­tion ques­tion to giant pan­das in a study pub­lished on 28 Feb­ru­ary in the jour­nal Behav­ioral Ecology.

The study, a col­lab­o­ra­tion between the Uni­ver­sity of Cal­i­for­nia, Davis, and Cal­i­for­nia State Uni­ver­sity, Long Beach, deter­mined that the giant panda’s dis­tinct black-​and-​white mark­ings have two func­tions: cam­ou­flage and communication.

Decon­struct­ing a giant panda
“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,” said lead author Tim Caro, a pro­fes­sor in the UC Davis Depart­ment of Wildlife, Fish and Con­ser­va­tion Biol­ogy. “The break­through in the study was treat­ing each part of the body as an inde­pen­dent area.”

This enabled the team to com­pare dif­fer­ent regions of fur across the giant panda’s body to the dark and light colour­ing of 195 other car­ni­vore species and 39 bear sub­species, to which it’s related. Then they tried to match the dark­ness of these regions to var­i­ous eco­log­i­cal and behav­ioural vari­ables to deter­mine their function.

Hid­ing in snow or for­est
Through these com­par­isons, the study found that most of the panda – its face, neck, belly, rump – is white to help it hide in snowy habi­tats. The arms and legs are black, help­ing it to hide in shade.

Giant pandaSci­en­tists ana­lyzed the sep­a­rate sec­tions of the giant panda’s body to deter­mine the func­tions of its black and white mark­ings.
Image credit: Ricky Patel

The sci­en­tists sug­gest that this dual coloura­tion stems from its poor diet of bam­boo and inabil­ity to digest a broader vari­ety of plants. This means pan­das can never store enough fat to go dor­mant dur­ing the win­ter, as do some bears. So it has to be active year-​round, trav­el­ling across long dis­tances and habi­tat types that range from snowy moun­tains to trop­i­cal forests.

The mark­ings on the panda’s head, how­ever, are not used to hide from preda­tors, but rather to com­mu­ni­cate. Dark ears may help con­vey a sense of feroc­ity, a warn­ing to preda­tors. Their dark eye patches may help them rec­og­nize each other or sig­nal aggres­sion toward panda competitors.

This really was a Her­culean effort by our team, find­ing and scor­ing thou­sands of images and scor­ing more than 10 areas per pic­ture from over 20 pos­si­ble colours,” said co-​author Ted Stankowich, an assis­tant pro­fes­sor at CSU Long Beach. “Some­times it takes hun­dreds of hours of hard work to answer what seems like the sim­plest of ques­tions: Why is the panda black and white?”

(Source: Uni­ver­sity of Cal­i­for­nia Davis news release, 03.03.2017)


Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
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