Bat richness and activity with acoustic methods in the Tandilia Hill System (Buenos Aires, Argentina).

Abstract

The Tandilia Hill System is a key refuge for biodiversity in the Buenos Aires Province, Argentina. Despite its importance, studies on the chiropteran fauna are scarce. The aim of this study was to assess the species richness and acoustic activity of insectivorous bats in the Paititi Private Nature Reserve. Acoustic recordings were conducted at 11 sampling points during December 2023 and January 2024 using an Echo Meter Touch 2. Nine species belonging to the families Molossidae and Vespertilionidae were identified. High levels of activity were recorded at most sites, with Tadarida brasiliensis and Histiotus montanus being the most active species. Additionally, reproductive colonies of H. montanus were documented in rock crevices, and individuals of Lasiurus blossevillii were captured in areas invaded by Blackwood (Acacia melanoxylon). This study is the first in Argentina to use acoustic methods to evaluate bat species richness and activity, providing essential data to inform potential conservation programs in the Tandilia Hill System.