Apart from boosting its migratory bird population, the Mai Po Nature Reserve now has another wildlife attraction - dragonflies. The marsh has 51 species of dragonfly, representing 45 per cent of the 112 dragonflies recorded in freshwater and brackish water habitats in Hong Kong. The findings came after a two-year field study conducted by the World Wide Fund for Nature Hong Kong. The group said it had recorded the dragonfly data to help it formulate a freshwater habitat management strategy. Of the 51 species, Mortonagrion hirosei, or the four-spot midget, is a globally endangered species listed by the International Conservation Union, while 15 others are rare or uncommon to Hong Kong. Alex Wong Wai-tung, education officer of the WWF, said the organisation was satisfied with the findings and believed the marsh to be a suitable habitat for dragonflies. 'The ponds in Mai Po are man-made and we wanted to find out the ecological performance of these ponds to help us plan future habitat management,' he said. The WWF said freshwater habitats in Hong Kong had been hit with water pollution, reclamation, and the invasion of exotic species, which had had a negative impact on dragonflies. 'The more we understand their ecology, the better we can work out how to manage them,' said Samson So Ngai-hung, WWF training officer.