Hawaii supports one of the world’s most spectacular radiations of land snails. Of the approximately 90 families of land snails found globally, Hawaii has representatives from only 10 (Figure 1).The real number of species is difficult to ascertain, because prior to this project, most have not been studied in a comprehensive systematic manner for almost a century. In 1990, after examining extensive museum material and published records Alan Solem, a snail researcher at the Field Museum Chicago estimated that Hawaii had at least 1461 species of land snails found nowhere else in the world. This estimate was more recently revised, and it was determined that only about 750 of those were valid, meaning that they had been properly described. However, the true number of species remains unknown, and is probably somewhere between these two estimates. For example, the family Endodontidae has 33 recognized species found in Hawaii, but Solem thought that at least an additional 290 awaited description in the Bernice P. Bishop Museum (BPBM), Honolulu. Despite such discrepancies even the most conservative estimates indicate that Hawaii is an incontrovertible snail diversity hotspot. Even more spectacular is that >99% of the species are found nowhere else in the world and many are restricted to single islands. The fauna is a biodiversity treasure and holds an evolutionary legacy that can provide valuable insights in the processes of speciation and generation of biodiversity.

Unfortunately, various estimates, based primarily on limited surveys and extrapolation from studies on a few snails, suggest that as much as 90% of this diversity had already been lost by 1990. A few species probably continued to persist in heavily altered low elevation sites but most of the remaining fauna were thought to be hanging on in high elevation sites protected as reserves or accessible only by helicopter or arduous hiking. This notion was articulated by snail researchers nearly a century ago: “The higher mountain slopes of the Hawaiian Islands offer an almost unlimited field of study…of land Mollusca”. Despite these hiding spots for diversity, it was clear that the time left to study and preserve this unique fauna was running out and without immediate intervention this distinctive and important biological treasure would become one of the many poster children of recent extinction--our generation’s Dodo.

The first major objective of this project was to conduct extensive surveys to determine what remained of the Hawaiian land snail fauna. In doing so, we were able to assess the conservation status of the remaining taxa, estimate how much of the diversity really has been lost, examine the relationships among the remaining snails, and describe any new species that we encountered.

Our survey work covered nearly 750 sites across the six main Hawaiian Islands and recorded more than 29,000 native snails. We collected voucher material from approximately 13,000 of these for genetic and anatomical analyses. This study quickly revealed that the demise of much of the land snail fauna had been overestimated and that much more than 10% of many families remained. Unfortunately, in several cases our work only served to confirm the devastation to this unique fauna.

Despite the diversity losses, we were still able to learn a great deal about Hawaiian land snail evolution, ecology and what to do to conserve the remaining taxa. We also discovered numerous new species, suggesting that original diversity was even higher than initially estimated.

Together with a large number of state, federal and local conservation agencies we have been using the data from this study to develop additional conservation and management plans to ensure the survival of these species into the future. Additionally, we have teamed with grade school teachers, museum education...

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