The Noah's Ark operation began last year when the Sinnamary river, on which the dam was built, burst its banks. It flooded 150 square miles of the Amazon rain forest, home to some of the rarest and most exotic species in the world.
Over the past year, the water has risen two inches a day, driving animals on to islands of raised land and into the trees. Early this year the water level reached 100 feet above normal, swamping the creatures' most far- flung retreats.
With funding from the French government and EDF, the electricity company which built the dam, a team of 40 French vets and students have worked against the rising waters to save 5,000 animals.
Using speedboats and dart guns to stun the creatures, the French team captured 1062 rodents, 515 possums, more than 1,000 sloths and armadillos, 214 monkeys, 1684 reptiles, including tortoises, 157 birds and other animals.
Animals such as rodents that could not climb were saved first. Towards the end of the operation the team took to boats. Monkeys proved the most difficult to capture, being agile and suspicious. After they had been anaesthetised they sometimes fell in the river and vets had to swim to catch them. But the sloths were equally unco-operative, being unmoved by all French blandishments.
"We had to shoot darts in them from the boats and climb up the trees," said Catherine Cloarec, who filmed the rescue. "They are not very fast, so at least you can see them easily. Three or four vets once swum to rescue an anaesthetised sloth."
Within a day of being captured the animals were released to safety 20 miles away in French Guyana's first national park.
The rescue work was filmed for a Channel 4 documentary, Flood Rescue, which will be broadcast tonight at 7pm.Reuse content