Population of hematophagous bats in the Andradina region, São Paulo: Roost and control characterization

Abstract

The present study quantified Desmodus rotundus population and characterized their roosts in the Andradina microregion, Sao Paulo, Brazil, in 2010 and 2012, determining the effect of bat control measures on roost numbers and types and their population. From April to June 2010, professionals from the Agriculture and Livestock Defense Coordination of the State of Sao Paulo responsible for the rabies control that consists of capturing and treating vampire bats with a vampiricide paste based on Warfarin 2%, inspected 50 bat roosts registered in 12 municipalities in the Andradina microregion, northwestern São Paulo. In September 2012, 31 of these roosts were again surveyed by the authors of this study. The vast majority (92% and 96% in 2010 and 2012, respectively) of the roosts were characterized as artificial, e.g., abandoned houses and warehouses, house attics, culverts under highways, deactivated wells and mills, bridges, disused housings, and barns. The only natural roosts found were tree hollows. The number of roosts and the bat population in roosts decreased drastically after the measures for direct control of hematophagous bats were performed, especially the number of maternity colonies, indicating that the direct selective method had a strong impact on reducing these populations.