London, January 19 (ANI): The recent sighting of an extremely rare giant panda with brown and white fur is raising fears that the species may be suffering from inbreeding.
In November 2009, a staff member at the Foping Nature Reserve in China's Qinling Mountains - one of the panda's last remaining strongholds - spotted a panda with the unusual colouring.
It was estimated to weigh around 2 kilograms, which would suggest it was less than 2 months old at the time.
This is only the seventh such animal spotted in the region over the past 25 years, Tiejun Wang, a spatial ecologist in the Department of Natural Resources at the University of Twente in Enschede, the Netherlands, told Nature News.
But the explanation for this unusual variety remains a mystery.
"It's time we had a debate about what is causing this because it could be telling us something very important," said Wang.
Wang and his Twente colleague Andrew Skidmore are concerned that the brown-and-white form indicates that breeding between closely related pandas is becoming more common.
Each panda has two versions, or alleles, of each of its genes, one inherited from its mother and one from its father.
Wang suggested that the Qinling pandas carry a dominant gene for black fur and a recessive gene for brown fur.
This means that pandas with brown-and-white fur are only possible when they inherit the recessive brown gene from both mother and father.
The chances that both parents have the brown allele are ordinarily very low, suggested Wang.
But the coincidence would be much more likely if the pandas were closely related.
"The habitat in the Qinling Mountains is seriously fragmented and the population density is very high," said Wang.
"The brown pandas could be an indication of local inbreeding," he added.
Conservationists worry about such inbreeding because it means that more animals rely on the same set of genetic defences to overcome environmental threats, increasing their risk of extinction.
According to Wang, brown-and-white pandas have only been seen in the Qinling population, one of five mountain regions where pandas still live in the wild.
Qinling is home to around 300 animals, roughly one-sixth of the total panda population in the wild.
The first recorded brown-and-white panda - a female called Dan-Dan - was discovered in 1985.
She was taken into captivity, mated with a black-and-white animal and gave birth to a normal black-and-white male.
A few years later, another brown-and-white panda was seen in the wild, together with its black-and-white mother.
"These anecdotal observations strongly suggest the presence of a recessive gene or genes," said Wang. (ANI)