Relationships Between Human Activity and Richness and Abundance of Some Bird Species in the Paraguay River (Pantanal, Brazil)

Abstract

The Pantanal region (Brazil) is under increasing anthropic pressure partly due to an increase in tourism and there is a lack of information about the influence of human presence on avifauna. Here we study the relationships between human activity in the river (boats and fishermen) and 15 bird species along a 70 km stretch of the Paraguay River, also including other confounding factors such as distance to towns and spatial autocorrelation. Human density along the river was low and as expected decreased with distance from towns. Bird richness and density were negatively associated with human density and the distance to towns along the river, suggesting a permanent impact on avifauna. Riparian forests had higher bird density. Four species were apparently sensitive to human presence: the anhinga Anhinga anhinga, the great white egret Egretta alba, the ringed kingfisher Megaceryle torquata and the southern screamer Chauna torquata. Thus, these species could serve as indicators of human pressure. Any management plan for sustainable development of the study area should preserve the riparian forest, consider the control of numbers of tourists and people in the river, and monitor the bird community, especially the sensitive species.