Commercial logging is a major economic activity in the Upper Baleh catchment, Sarawak, so logged-over forest is the dominant forest type there. Avifauna survey was conducted in the logged-over forest of Upper Baleh in November 2015 as part of the Upper Baleh Heart of Borneo Expedition. The objective of the survey was to collect baseline data on the avifauna species that inhabit the study area, their conservation status and feeding guilds. Both mist-net and observation method were used. A total of 95 species of birds was recorded: 36 species via mist-nets and 69 species via observation. Little spiderhunter was the dominant species, accounting for 33% of mist-netted bird. Seven species are Totally Protected including six species of hornbills and a Great Argus Pheasant, while 18 other species are Protected under the Sarawak Wild Life Ordinance 1998. The majority of the birds are insectivorous (55.8%), foraging either at ground level (babblers), along the tree trunks or branches (woodpeckers) or at the canopy (flycatchers). Omnivorous birds, which feed on two or more types of diet, accounted for 48.4% of the avifauna species recorded and these include bulbuls and hornbills. The diverse community of bird, including the protected species, makes the area an attractive birding destination for visitors since now part of the catchment has been gazetted as a national park. Avifauna’s role as pollinating and dispersing agent will help the logged-over forest to recover. Keywords: conservation status, feeding guilds, Heart of Borneo, logging roads

Babblers are the primary insectivorous birds of the tropical forests in southeastern Asia which have shown to be affected by forest disturbance. Their high diversity, microhabitat specificity and specialised feeding guilds provide a good opportunity for ecological research pertaining to niche segregation. We examined the diet and foraging strata of 15 sympatric babbler species mist-netted in nine forests in Sarawak, eastern Malaysia. Based on 222 birds captured from December 2014 to March 2016, a segregation in foraging strata was found, with half of the species captured frequenting low strata, while only three were found at mid strata and four at high strata. Both species richness and abundance were found to decrease when the foraging height increased. From a total of 136 prey items retrieved from regurgitated and faecal samples of 13 babbler species, we found that Coleoptera (41.5%), Hymenoptera (36.2%), and Araneae (12.3%) formed the major diet of the birds. Diet overlaps among the babblers were relatively low. Our study demonstrated the possible presence of spatial and trophic niche segregation among babblers, and justified their ecological role as indicators of tropical forest ecosystem health, especially in the case of specialists, that deserve further conservation attention.