Status, conservation, and management of the land snails of the genusPowelliphanta(Mollusca: Pulmonata)

Abstract

The distribution and the condition of the habitat of each of the land snails in the genus Powelliphanta are presented and the predation on each is reported. Distribution was assessed from field surveys and the literature, habitat from the condition of the vegetation, and predation from collections of empty shells showing diagnostic patterns of damage by rats, pigs, wekas, either kakas or keas or both, and either European blackbirds or song thrushes or both. The current status of each member of the genus is thereby assessed, and all are ranked in order of conservation priority. All members of the genus have suffered to some extent from habitat loss, habitat modification by browsing ungulates, and predation by introduced predators since European settlement of New Zealand. A few members of the genus are close to extinction. Management recommendations are made for all vulnerable members of the genus.