In Aesop's fable, the country mouse scurried home from the city with his tail between his legs. But in Paris, French bee-keepers are finding their charges have better luck in the buzz of the big smoke than they do in rural climes – living longer and producing more honey.

While bee colonies across rural France are dying in swarms, two beehives that have been on the roof of a giant exhibition hall beside the Champs-Elysées since last spring are thriving.

The experiment in urban living for bees is intended as a warning signal to the French government, which has been accused of ignoring the plight of rural bees and bee-keepers.

In May, the Grand Palais exhibition hall decided to place two beehives on the edge of its huge glass and steel dome. Each beehive contains over 80,000 "buckfast bees", a British species described by experts as "gentle, prolific and resistant". Four months later, more than 100lb of honey has been gathered from the two hives.

It is not the prestigious address or magnificent views which make the bees so productive. What they adore is the urban environment, even though it is heavily polluted by car exhaust.

"We notice that apiaries located in the heart of Paris get better results than those in the countryside," explained Nicolas Géant, the French bee-keeper who initiated the project at the Grand Palais in order to draw attention to the predicament of rural bees.

"Towns offer myriad small flowers in parks and on balconies, as well as a wide variety of trees along streets and in public gardens. By contrast, there is no longer enough food for bees in rural and cultivated areas. The mortality there is 30 to 50 per cent but very small in Paris."

Henri Clement, president of France's main apiarist union, Unaf, says changes in French agriculture have damaged the bees' habitat. "Both monoculture and the intensive use of pesticides, fungicides and fertilisers kill massive numbers of bees," he explained.

For the moment the new tenants of the Grand Palais seem to be enjoying their life in the busy capital. "We have not received complaints from them yet," jokes Majorie Lecointre, one of the managers of the exhibition hall. Three additional beehives will be placed on the Grand Palais roof early next year.

But the city slickers will not be enough on their own to save beekeeping – and the crucial role it plays in agriculture, severely under threat because of a dramatic decline in bee populations.

"People have to keep in mind that the future of beekeeping is not in cities," said Mr Clement. "Bringing bees into cities is just a way to ring the alarm bell for the French government. We need to have bees back everywhere in France because 35 per cent of global food resources depend on insects and 80 per cent of that is from pollination by bees."