A pair of giant pandas gifted by the central government to the Macao Special Administrative Region arrived in Macao in April. [Photo/Xinhua]

Worried about the low sex drive of giant pandas in zoos, scientists have tried many things to get them in the mood－including Viagra and "panda porn".

When all else failed, they've turned to artificial insemination to ensure the endangered black and white creatures have cubs.

On Tuesday, a study suggested the answer may be a lot simpler and, perhaps, more obvious: Let the pandas choose their own mates.

"Giant pandas paired with preferred partners have significantly higher copulation and birthrates," researchers said in the journal Nature Communications.

Generally, pandas in captivity are presented with a mate chosen by scientists based on the animals' genetic profiles. The goal is to minimize inbreeding and expand the DNA pool.

But the result is often frustrating, with the animals having to be coaxed through human intervention to show even the slightest sexual interest in whatever mate is paired with them.

A team from the United States and China ran a test at the China Conservation and Research Centre for the Giant Panda in Sichuan province to see if being allowed to choose their own partners might make a difference.