The birds of Anak Krakatau: the assembly of an avian community

Abstract

The avian colonization of Anak Krakatau, an emergent volcanic island, is described for the period 1952–1991 with emphasis on the resident land birds. The few species that had colonized the island by 1952 were destroyed in a volcanic eruption. Recolonization has been rapid and extensive but only documented by regular surveys that began in the 1980s. The waves of avian colonists associated with the following stages of plant succession are described: pre-vegetation, beach and grassland pioneers, casuarina woodland and mixed forest. Rainforest frugivores first reached the island in 1985 coinciding with the fruiting of the first fig trees. The three stages of plant succession and the bird communities associated with them co-exit on three separate lowland sites with about a 10–15 year delay between them. The guilds of shorebirds, predators, nectarivores, frugivores and insectivores are described. Densities of insectivores are very high; however between 1986 and 1990, some generalist species have fallen in abundance whereas some specialists have increased. The establishment species have fallen in abundance whereas some specialists have increased. The establishment of new colonists, especially pigeons, has been limited by the arrival of two species of falcons.