Research Interests

The extinction rate among snail species of the endemic Hawaiian subfamily Achatinellinae (Pulmonata) exceeds 50% in recent times. Members of the genus Achatinella are on the U. S. Endangered Species List and were identified by the International Union for the Conservation of Nature and Natural Resources (IUCN) as being among the world's 12 most endangered animals and plants. Remaining populations of achatinellines are small, scattered and restricted to higher elevations on five Hawaiian islands. The plight of the achatinelline snails is probably only one notable example of what has occurred in the 800 or more species of endemic terrestrial gastropods which occurred in Hawai`i at the time of European contact. In spite of the great popularity of the shells of achatinelline snails (they are colorful and highly variable) for more than 150 years, information about their general biology, demography and life-histories has been scant and anecdotal. To gain an understanding of both the high speciation rates which occurred in this snail subfamily in Hawaii and the rapid rate of disappearance now observed, we have been conducting field studies on populations of four achatinelline snails for more than twenty years. An earlier study was terminated when the study population was decimated by an introduced predatory snail. Our studies consist of classical multiple mark-recapture investigations of well delineated populations; they yield both standard demographic data and additional information on natural history, causes of death, dispersal and, to a small extent, behavior. We also employ molecular genetic studies to distinguish gene pools of isolated populations in order to plan conservation strategies in the field and the lab. These genetic studies are being extended to achieve understanding of the evolutionary radiations in the Hawaiian Achatinellidae. Captive-rearing efforts have been so successful that we now have more than 800 snails in our laboratory, including a species that no longer occurs in nature.