VIENNA, May 25 (AFP) - Vienna's famed Opera House is buzzing with a star new attraction this season: a beehive on its roof to celebrate the international year of biodiversity.

Some 60,000 bees have taken up residence high above the venerable opera house and have already started churning out honey, say the project organisers.

The rooftop stars are part of a green project called "Vielfaltleben" (Diversity of Life) sponsored by Austria's environment ministry.

As true opera divas, the bees' every move will be caught on camera and broadcast via webcam link on www.bienenfreunde.at/livecam.

"Bees are the builders of biodiversity... With this project, we want to raise awareness about these hard-working but also endangered insects," Environment Minister Nikolaus Berlakovich told a press conference Tuesday.

Part of the Vienna Opera's hoey will be sold at an upcoming gala evening, with profits going to Vielfaltleben projects.

After cattle and pigs, experts say bees are the third most important species of "farm animal", helping to pollinate 80 percent of plants.

Bee populations have been mysteriously declining in recent years in the United States, Europe, Japan and elsewhere, threatening agricultural production worth tens of billions.

According to the World Organisation for Animal Health, the die-off is due to a combination of parasites, viral and bacterial infections, pesticides, and poor nutrition caused by the impact of human activities on the environment.