9322600 Nussbaum Madagascar is a large, continental island located in the western Indian Ocean off the east coast of Africa between 12 degree and 25 degree S latitude. It has been completely isolated for at least 100 million years. Because of its large size and long isolation, it has developed a highly diverse and largely endemic fauna and flora. It has many small and unusual groups, such as the lemurs with only 24 species, and other equally distinctive groups that have speciated spectacularly. These include the orchids with more than 1,00 species and the amphibians and reptiles with an estimated 500 species. The high degree of endemism and the great diversity of Madagascar's fauna and flora combined with an astonishing rate of habitat destruction has prompted conservation organizations to give Madagascar top priority for conservation efforts. Two years of a 3-year survey of the amphibians and reptiles of the diminishing tropical rainforests of Madagascar have been completed. The main purposes of this survey are to (1) identify centers of endemism and high diversity in order to understand the evolutionary history of the herpetofauna and to aid in developing new rainforest reserves; (2) obtain specimens for systematic studies which will result in a better understanding of the origins and relationships of the Madagascan herpetofauna; (3) publish taxonomic monographs and field guides; and (4) train Malagasy students, scientists and other personnel charged with managing natural resources. Results from the first two years include a dramatic increase in the knowledge of the distribution, ecology, life history, and evolutionary relationships of rainforest amphibians and reptiles; the rediscovery of 31 extremely rare species; and the discovery of 132 new species. A national research and teaching collection of amphibians and reptiles has been established in Madagascar, and two Malagasy graduate students have completed their M.S. degrees in association with this project. The current proposal is to continue surveying amphibian and reptile communities in Madagascar, but to shift attention from the eastern rainforests to the dry forests of western Madagascar. These dry forests contain some of the most interesting and unusual species of plants and animals in the World; and their distributions, abundance's, habitat requirements, and adaptations are poorly understood. The dry forests are already degraded and threatened to at least the same degree as the rainforests, and their destruction is accelerating as the demand for resources increases. Very few reserves exist to protect the unique habitats of madagascar's dry forests. Twenty-two sites throughout the arid regions would be surveyed over a 5-year period, including sites in all four major types of dry forest (deciduous, gallery, spiny calcareous-canyon). The same methods used successfully during the rainforest surveys would be employed. The goals are much the same as for the rainforest surveys, and when combined with the results of the rainforest surveys would give a comprehensive picture of the diversity, ecology, evolution, systematics, and conservation challenges of the Madagascan Herpetofauna.