Like many normal young couples starting a life together, Huan Huan and Yuan Zi have moved into a new home, happily go about their daily business, and hopes are high for a baby.

But nothing else is normal about them. Their residence costs more than a million dollars a year, 10,000 humans come to gawk at them every day, and bitter failure has met most of the chosen few who took the rocky road to parenthood before them.

Not that any of that bothers Yuan Zi ("Chubby" in Chinese) or his female partner Huan Huan ("Happy"), or the hordes of tourists who are thrilled by the indolent exploits of the giant pandas in Beauval zoo in the French countryside.

Yuan Zi, as if to show his indifference, took a break from munching bamboos in morning sunshine to turn his rear end towards a crowd of excited onlookers and, to cries of delight, produce a large, shining, green deposit.

"They eat 35 kilos (78 pounds) of bamboo a day and defecate about 30 kilos a day," explained zoo director Rodolphe Delord, as he hosted yet another media crew reporting on the "pandamania" that erupted since they arrived in January.

Visitors to Beauval, whose tree-lined alleys and collection of 4,500 animals helped make it onto Forbes Traveller magazine's list of the world's 15 most beautiful zoos, last year welcomed 600,000 visitors, double the number from three years earlier.

Attendance figures shot up by a further 50 percent in recent months, largely due to the cuddly black and white bears who are the star attraction in a new two-hectare Chinese section complete with pagodas and marble lion statues.

There they are monitored round the clock by security guards and surveillance cameras, and during the day crowds swarm to see them snooze or eat the frozen apple, honey and ice treat they have been getting during a recent heatwave.

A zookeeper comes to their enclosure every hour during the day and gives a presentation that explains that the panda is an endangered species with only about 1,600 remaining in the wild in China and some 300 others in captivity worldwide -- mostly in China, but also in just 15 foreign zoos.

Huan Huan and Yuan Zi, who have just reached maturity at the age of four, came from China's panda conservation centre in Sichuan province and are in Beauval on a ten-year loan -- for which the private zoo is paying China around a million dollars annually.

The pair are in France as another example of "panda diplomacy" -- China's bid to use "soft power" to boost its image and strengthen diplomatic ties with a country by loaning the popular bears.

There is immense pressure on Beauval to get the pair back to China in good shape. "We're a little stressed because we're accountable to them," said zookeeper Astrid Bernasconi.

-- Some zoos have tried giving male pandas Viagra --

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There is also great pressure to make sure that the couple produces offspring. The section of the zoo where they are kept has an optimistic sign declaring that it is the "Conservation and Breeding Centre of Giant Pandas".

But captive pandas are notorious for their reluctance to breed.

A stark reminder of that came just last week with the demise in Berlin Zoo of Bao Bao, at 34 the oldest known male panda in the world. He died cubless despite having procured a series of females since his arrival in Europe in 1980.

Other examples of panda reproductive failure abound. A pair gifted to Britain in 1974 remained cubless to the end, while the last pair of pandas that lived in France were an embarrassing disaster in breeding terms.

China's Chairman Mao gave the couple to President Georges Pompidou but it soon emerged that they were in fact a pair of males, one of whom died after just a few months in France.

Some of the more extreme methods used to get pandas to copulate have included showing them videos of other bears mating and even supplying the male with Viagra.

Here in Beauval the zookeepers -- including a pair from China who will stay throughout the bears' 10-year French sojourn -- are taking a more scientific approach.

They take frequent blood samples and carry out other tests to make sure they don't miss the mere 48 hours a year during which Huan Huan will be fertile.

The bears live in adjacent but separate enclosures from which they can see but not touch each other, and as soon as it looks like the female is ready, zoo staff will open up the barriers to let them hook up.

"We mostly keep them apart because if they get too familiar with each other, then they tend to lose interest," explained zoo director Delord, adding that if nature does not take its course then they will try artificial insemination.

There is no guarantee that a cute little panda cub will result from the Beauval pair's first coupling, as was illustrated earlier this year when Britain's only pandas failed to mate during their brief window of opportunity.

It was "close, but no cigar", Edinburgh Zoo said, after Yang Guang (Sunshine) mounted female panda Tian Tian (Sweetie) several times, without full mating taking place.

Huan Huan and Yuan Zi meanwhile carry on with their daily 14 hours of feeding, blissfully unaware that here in Beauval they embody the claim in George Orwell's novel "Animal Farm" that all creatures are equal, but some are more equal than others.