Hundreds of endangered tree snails have been sent back to their native island of Tahiti as part of an international zoo conservation project.
The Royal Zoological Society of Scotland (RZSS) sent four varieties of Partula snail which had been bred at Edinburgh Zoo, to be released into the snail's native range in Polynesia.
Partula snail populations were decimated in the 1970s after the predatory 'rosy wolf snail' was introduced from Florida to rid the islands of a previously-introduced alien species - the giant African land snail - but instead, the rapacious predator devoured the tiny native snails.
The release is the result of an international collaborative breeding programme between zoos and collections across the world, including Bristol Zoo, Chester Zoo, Marwell Zoo, RZSS and ZSL London Zoo in the UK alone.
Gareth Bennett, senior presenter at RZSS Edinburgh Zoo, said: "We are proud to have been part of helping to restore the Partula snail back into its native habitat for many years now.
"Edinburgh Zoo has been involved in the conservation of Partula snails since 1984 and was even given the very last individual of the Partula taeniata simulans variety in 2010 which the Zoo bred back to a safe level of several hundred.
"We were very pleased to learn that the reintroductions have gone so well and that snails from earlier releases have been found within the habitat continuing to thrive.
"This is a wonderful conservation success story and further demonstrates the critical role zoos can play in species conservation. The reintroductions are historical landmarks, not only for Polynesian tree snails, but for wildlife conservation in general because the results we are seeing are made possible through the hard work of committed zoos working together as part of an international breeding programme."
RZSS said 652 snails from across the partnership were released in Tahiti.
The various subspecies of Partula snails kept in captivity are managed under the International Partulid Conservation Programme, which combines the breeding programme in 15 different institutions around the world with conservation work in the Polynesian islands.
Around 46 out of 65 identified species of Polynesian Partula are extinct.