Since the cataclysmic eruption of 1883, 25 species of bats, of which 11 are pteropodids, have recolonized the Krakatau Islands and adjacent areas of West Java, Indonesia. Sixteen have been recorded on the Krakatau Islands. Documentation of the recolonization process has been sporadic, and almost certainly incomplete, but it is apparent that pteropodids have been the first bat colonists of the Krakatau archipelago. On the main island of Rakata, and on the more recently formed island of Anak Krakatau, Cynopterus sphinx had established itself about 20-30 years after the cessation of major eruptive activity. Movements of pteropodids between the islands and the mainland are of clear importance in the re-establishment of vegetation. Microchiropterans have been recent arrivals, probably recolonizing Rakata between 50 and 70 years after the 1883 eruption, but they were still absent from Anak in 1986.