Abundance waterbirds and the distribution of trees nesting in Pulau Rambut (Rambut Island) wildlife sanctuary, Jakarta Bay, Indonesia

Abstract

Abstract Pulau Rambut is a small island in Jakarta Bay that has been used as a breeding and roosting habitat for various waterbird species. The study aimed to estimate waterbird’s abundance, comparing waterbirds species and abundance data with previous studies in 1990 and 2001, and mapping the distribution of nesting trees. The study was conducted in January-February 2020. Birds were counted using the census method, while the coordinates of nesting trees were taken to map their distribution. There were 13 species of waterbirds (5 egret species, 2 day-heron species, 2 Cormorant species, 1 night-heron species, 1 darter species, 1 stork species, 1 Ibis species). Two species, the Black-headed Ibis and the Little pied cormorant were not found anymore compared to previous studies. The abundance of waterbirds was 4,950 individuals dominated by cormorant species (32%), egret species (28%), and Black-crowned night heron (23%). The number of waterbirds decreased sharply compared to previous studies. Nesting trees were distributed mostly in the east of the island, consisted of 3 sub-colony.