The odonate species richness of the granitic islands of Seychelles, a biodiversity hotspot, is significantly correlated to island size. The larger islands also have the highest elevations and hence the most streams from cloud catching as well as from downpours. The Seychelles odon. fauna can be divided into 2 groups: (1) endemic spp„ and, (2) geographically-widespread eurytopic, vagile spp. The endemic spp. are elevational fugitives that need high-elevation forest cover, even if secondary. They are remarkably tolerant of temporary drying out of streams. In contrast, the widespread spp. occur at low elevations, are pool spp., and are tolerant of removal of forest cover. They emigrate when the pools dry out. Conservation of the endemic taxa depends on maintaining cloud-catching forest, although evidence suggests that their populations are maintained even where the forest is partly alien invasive trees or secondary regrowth.