This research concerns the role of aggression, reproductive mode and clonal diversity in the observed competitive displacements among geckos in the tropical Pacific. The PI has documented a wide-scale biogeographic pattern in which a house gecko, Hemidactyplus frenatus, upon introduction to islands in the Pacific, replaces other species as the common urban gecko. Two of the species (H.garnotti and Lepidodactylus lugubris) being replaced reproduce parthenogenetically. There is a strong negative numerical effect of H.frenatus on L. lugubris both locally and on a broad geographic scale throughout the Pacific, and also a strong agonistic asymmetry between H.frenatus and L. lugubris. This research will assess factors that enable an invading species to cause a decline in native species. The experimental design will test the hypothesis that the agonistic dominance of H. frenatus over L.lugubris is the primary mechanism of competition, but will also enable quantification of exploitative mechanisms. With the use of 20 abandoned aircraft revetments constructed during World War II (located on the grounds of N.A.S. Barbers Point on Oahu), the PI can manipulate components of agonistic interaction and prey distribution on a large scale with many replicate treatments. %%% The results will be applied to the preservation and management of native communities, with the goal of protecting these communities from invading exotic species.
