Ecos nocturnos: Caracterización vocal de dos grupos sociales de Aotus griseimembra en fragmentos de bosque de San Juan del Carare, Cimitarra, Santander, Colombia

Abstract

This study characterizes the vocal repertoire of two wild social groups of Aotus griseimembra from the Middle Magdalena region of Colombia. Over a four-month period, bioacoustic monitoring was conducted, resulting in 4,191 vocalizations suitable for acoustic analysis. Eleven vocalization types associated with specific behaviors were identified, two of which are newly described for the genus (Gimoteo and Ladrido). Statistical analyses indicated that all acoustic parameters were significant for call classification, and discriminant analyses revealed that peak frequency and note duration contributed the most to their differentiation. Comparisons between social groups showed few acoustic differences among vocalizations; only Barks, Owls, and Screeches exhibited apparent variation, likely influenced by individual traits or group size. At the interspecific level, significant differences were found across all vocalizations when compared to Aotus lemurinus, possibly reflecting ecological factors, acoustic niche divergence, and habitat structural characteristics.