Polynesian tree snails

Polynesian tree snails

The family Partulidae comprising three genera is a classic example of adaptive radiation having evolved into about 125 species across tropical islands of the South Pacific. It has also become a text book conservation case study. Of the 77 species belonging to the genus Partula, 51 became extinct and 11 survive only in captivity. These catastrophic losses followed the introduction of a carnivorous land snail in a failed attempt to control the giant African land snail: another species that was alien to the islands and that had become a horticultural pest.

Our animal collection includes eight species of rare Polynesian tree snails of which six are Extinct in the Wild. We are part of a consortium of nine international zoological institutions monitoring the status of remaining wild populations, and working on the reintroduction of species that have disappeared from nature. As part of that process we are studying adaptation in Partula snails and seeking to understand the genetic and behavioural demands of returning these animals to nature. Because of their small size and short generation lengths, we are able to measure changes over multiple generations across entire populations, providing a model that should be applicable to other species.