Effects of surface fires on understorey insectivorous birds and terrestrial arthropods in central Brazilian Amazonia

Understorey insectivorous birds are highly vulnerable to different forms of habitat disturbance in tropical forests. Here we examine the effects of an unprecedented surface fire on understorey insectivores and forest litter arthropods in a terra firme forest of central Brazilian Amazonia, and compare species and guild abundance both close to and far from the clearly distinguishable fireline separating burnt and unburnt forest. All six of the most abundant insectivorous foraging guilds examined were detrimentally affected by fire, with dead-leaf gleaners and professional ant-followers being the most heavily affected. While army ants were apparently absent from the burnt forest, results from pit-fall traps showed that wildfires had only a limited effect on the abundance of most leaf-litter invertebrates. The fireline appeared to be an abrupt barrier to many understorey insectivorous birds, and there was little evidence to suggest that primary forest species were recolonizing burnt forest up to 1 year after the fires. Factors affecting the capture frequency of insectivorous birds are discussed.