With its striking coloration, the giant panda is an instantly recognizable species.

A handful of giant pandas that aren’t black-and-white, however, do exist. These majestic creatures with brown-and-white fur inhabit a single mountain range in China. And now, scientists may have unraveled the mystery of the extremely rare pandas’ unusual coats, according to new research.

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The work, which involved studying the genetics of multiple pandas in the wild and in captivity, has suggested that pandas with brown-and-white coats are the result of natural variation, rather than a sign of inbreeding in a dwindling population.

The first brown panda known to science was a female named Dandan. A local ranger found the ailing bear in Foping County in Shaanxi province’s Qinling Mountains in March 1985. The panda was held in captivity until her death in 2000.

Since Dandan’s discovery decades ago, there have been 11 reported sightings documented through official news sources or personal accounts shared with the authors of this latest study that appeared in the journal PNAS on March 4.

“The recurring instances of brown pandas imply that this trait may be inheritable. However, to date, the genetic basis underlying the brown-and-white coat color remains unclear,” the authors wrote.