Curry, Patrick2016-02-192016-02-192012-12http://hdl.handle.net/10125/100899M.S. University of Hawaii at Manoa 2012.Includes bibliographical references.Island land snail species, have suffered major extinctions, partly resulting from impacts of alien species. Oxychilus alliarius is a widely introduced predatory European snail. This thesis includes two studies: 1) assessing its spread and impacts on native snails on Kaala, Oahu's highest mountain; 2) modeling the environmental factors that determine its distribution in Hawaii, and applying those models to predict its potential tropical/subtropical island distribution globally. On Kaala O. alliarius is expanding its distribution at ~113 m per year. Abundances of native snail species on Kaala are correlated to that of O. alliarius in complex ways. Of 36 models developed, the four best were good predictors of O. alliarius distribution in Hawaii, with mean annual temperature being especially important. Globally, the models predict that some islands have areas of suitable habitat, mostly at higher elevations, and are therefore susceptible to invasion by O. alliarius, while others have no suitable habitat.engOxychilus alliariussnailspecies distribution modelingKaalaThesis