Green turtles return to their birthplace to breed - and it is this homing instinct that threatens the species' survival. Development of coastal areas, increasing marine traffic and pollution all work against the green turtle, but the greatest threat comes from villagers stealing eggs. The only known local breeding site is Sham Wan beach, Lamma Island, where four empty nests were found in 1995. Last September, conservationists feared a lone female had returned in vain after villagers stole her eggs. Reptile expert Michael Lau Wai-neng said collecting the eggs - a traditional delicacy - threatened the green turtle with extinction. The population would never be replenished, Mr Lau said: 'In general they are threatened by development. The green turtle is a species which has been over-exploited. 'With regard to this population, the major threat would be collecting of eggs by villagers.' Hunting of turtles and their eggs is prohibited under the Wild Animals Protection Ordinance, designed to protect all species of turtles and terrapins. Eleven species have been recorded locally but only the green turtle breeds in Hong Kong, although since the 1970s only a handful of them have been recorded. Trade in the green turtle is also controlled under the Convention on International Trade in Endangered Species of Flora and Fauna. Seven illegally imported stuffed green turtles have been seized this year.