A comparison of bird communities of two fragmented and two continuous southeast Asian rainforests

Abstract

A large proportion of forest-dependent bird species have disappearedfrom Singapore, probably due to heavy forest loss that started in the 1800s. Thebird fauna seems to have relaxed (attained a lower and relatively stablediversity following habitat destruction) in Singapore. Using mist-netting, Icompared understory bird communities of two lowland rainforest fragments inSingapore (Nee Soon and MacRitchie) with two continuous forests in Sarawak(Malaysia) (Matang Wildlife Sanctuary and Gunung Gading National Park). Icompared community characteristics (e.g. rarity [<2 individuals/1000mist-netting hours]), population characteristics (e.g. sex ratio) and individualquality (e.g. prevalence of ectoparasites) among avifaunas of the forests. Onaverage, more bird species and individuals were caught in continuous foreststhan in fragments. There were more rare species in Gading. The proportion ofadults and the sex ratios did not differ among the forests. Ectoparasiteprevalence and intensity also did not differ among the forests. Proportionallymore individuals contained fault bars in MacRitchie. My study shows that aviancommunities in rainforest fragments are depauperate but show few signs ofenvironmental stress. Thus there may be long-term resilience in some forest birdspecies. However, it is essential to protect large tracts of tropical lowlandrainforest to preserve rare forest-dependent avifauna.