AN INTEGRATED CONSERVATION PROGRAM FOR THE TREE SNAILS (PARTULIDAE) OF POLYNESIA - A REVIEW OF CAPTIVE AND WILD ELEMENTS

The introduction of the predatory snail, Euglandina rosea, into the tr ee snails' Polynesian range, has led many species to extinction, and h as resulted in the development of ex situ and in situ conservation eff orts for the remaining species of the family Partulidae. Over a 10 yea r period the programme has moved from art emphasis on captive bleeding and rescue of doomed populations, to trial release programmes. In Jan uary 1996 a total of 17 participating toes and universities in Europe and North America were maintaining over 30 partulid species and subspe cies in culture, totalling over 14,000 snails. Target ex situ populati on sizes required to maintain 90% of starting heterozygosity over 100 years have been calculated. The conservation status of all 117 species of the Partulidae has been assessed using the Conservation Assessment Management Plan process. A relational database has been developed to support population analysis for management. The ability of long term c aptive-bred snails to readapt to natural field conditions was investig ated using a trial release and monitoring experiment at Kew Gardens. F ield release trials in a predator-proof forest reserve commenced in 19 94 and continue to be assessed. Since its commencement in 1986 the par tulid conservation programme has experienced mixed results with both n otable successes and failures. The programme provides conservationists with a model for developing future conservation programmes for other threatened mollusc species.