Echolocation pulses of the endemic Bat Saccopteryx Antioquensis (Emballonuridae) in Antioquia, Colombia

Bioacoustics is an effective tool for identifying insectivorous bat species, particularly those that forage in the upper forest strata and show low capture probabilities using traditional methods. However, for many rare or range-restricted species, available acoustic information remains limited. In this study, we present the first acoustic description of Saccopteryx antioquensis, an endemic and threatened species restricted to karst ecosystems in southeastern Antioquia, Colombia. We describe echolocation pulses based on reference recordings obtained from an individual captured in 2020 and on free-flying recordings collected in 2022. Echolocation pulses of S. antioquensis were characterized by the alternation of low-frequency (LF) and high-frequency (HF) pulses, inverted U-shaped spectrograms, and a multi-harmonic structure, with most energy concentrated in the second harmonic. Spectral and temporal parameters exhibited distinctive frequency ranges compared to other species within the genus. Multivariate analyses revealed significant acoustic differentiation between S. antioquensis and other Saccopteryx species for both LF and HF pulses, supporting its acoustic identity and interspecific separation. This information provides a solid baseline for acoustic identification and passive monitoring of the species and represents a key tool to support conservation strategies in a context of high anthropogenic pressure on karst ecosystems. Overall, this study contributes to the knowledge of Neotropical bat bioacoustics and highlights the value of acoustic monitoring for the conservation of endemic and threatened species.