Bird community responses to disturbance in a forestry concession in lowland Bolivia
Bird community characteristics of three sites with different levels of disturbance were studied using transect surveys during the dry season in a subtropical humid forest in Bolivia. One area had been unintentionally burned 4 years prior and selectively harvested (DIS) 1 year prior to sampling. A second area had been selectively harvested 1 year prior to sampling and had no recent history of fire (HAR). Species richness, as assessed by species-time curves and rarefaction, was higher in both altered areas than in undisturbed forest (INT). In general, frugivores and omnivores were more abundant in both altered areas compared to intact forest. Canopy frugivores, understory omnivores and multiple-strata omnivores were most abundant in HAR. Canopy frugivores, near-ground insectivores, understory and multiple-strata omnivores were least abundant in INT, although INT had the highest abundances of canopy insectivores and near-ground omnivores. Richness and abundance of widespread species with low habitat specificity was higher in both areas that experienced disturbance compared to intact forest. Differences in bird community structure between disturbed and intact forest at this site are attributed primarily to the addition of widespread species with less narrow habitat requirements, and possibly to changes in the distribution of different food types.