La Colección Mastozoológica de la Universidad de Nariño (Colección Zoológica P.S.O-CZ) conserva 926 especímenes de mamíferos pertenecientes a 10 órdenes, 25 familias (23 nativas y dos exóticas), 75 géneros (73 nativos y dos exóticos) y 119 especies nativas, más dos exóticas. Los especímenes proceden de cinco departamentos del país, con una mayor representación de Nariño y Putumayo. Aproximadamente 405 especímenes fueron donados por la Fundación para la Educación Superior (FES), provenientes de la Reserva Natural La Planada (Municipio de Ricaurte, Nariño) y otros especímenes que han sido colectados por estudiantes de la Universidad de Nariño. Los ejemplares de la colección han sido referenciados en al menos 22 publicaciones científicas.

Diversity surveys may be performed by different sampling methods. In the case of bats, the use of traditional methods such as mist nets, harp traps, and roost detection have limitations in widely covering the diversity in a landscape. Most registered species are restricted to species that forage at the undergrowth or in enclosed spaces. However, acoustic monitoring is complementary to conventional methods and can help obtain more complete bat inventories while avoiding alterations in usual foraging activities and disruption in their life cycles. This study describes the acoustic parameters (spectral and temporal variables) of the echolocation pulses of insectivorous bats to characterise acoustically different species of bats present in southwest Colombia. We recorded echolocation calls between December 2017 and May 2020 in the Andean and Pacific regions of the department of Nariño. A total of 81 sequences from free-flying bats were analysed from eight species belonging to three families: Vespertilionidae, Molossidae and Emballonuridae. Myotis riparius and Lasiurus blossevillii were registered for the first time in Nariño Department. The species M. albescens, M. keaysi, M. riparius and L. blossevillii (Vespertilionidae) had pulses of frequency modulated with a quasi-constant ending; Molossus molossus, Tadarida brasiliensis and Promops centralis (Molossidae) had pulses with constant and quasi-constant frequencies; and Saccopteryx bilineata (Emballonuridae) had pulses with quasi-constant frequencies. This study enriches the efforts to solve acoustic species classification issues of insectivorous bats in the Neotropics.