The Vocal Repertoire of the Bearded Capuchin (Cebidae: Sapajus libidinosus): Implications for Understanding the Complexity of Neotropical Primate Communication

Vocal communication is an essential aspect of primate social behaviour. The bearded capuchin <i>Sapajus libidinosus</i> is endemic to Brazil, and some studies have described specific vocalisation types for this species; however, there is still no complete description of its vocal repertoire. Thus, this study aimed to describe the vocal repertoire of a group of <i>S. libidinosus</i> living in the<i></i>Parque Nacional de Brasília, a protected area in the Cerrado area of Central Brazil. We carried out focal samplings and recording of vocalisations of members of an <i>S. libidinosus</i> troop in different behavioural contexts. The call analyses revealed 25 different types of vocalisations, and each call presented significant structural variation. We grouped these vocalisations according to the context of the emission or acoustic structure into the following categories: contact calls (contact note, infant babbling, trill, teeth- and lip-smacking, and sirena); foraging calls (chihui, grgr, and patinado); whistle series (food-associated, long-distance, and intergroup encounter); aggressive calls (aggressive contact note, ascending rapid staccato, cough cough, and pip); calls in response to aggression (scream, squeal, and pulsed scream), sexual display calls (chuck and raspy oestrous call), and stress-related calls (alarm call/bark, hiccup, hip, double hip, and wah wah). <i>S. libidinosus</i> presented a very rich vocal repertoire, revealing a pattern consistent with the repertoire of other capuchin monkey species. This is the first comprehensive description of the<i> S. libidinosus</i> vocal repertoire and highlights the complexity of neotropical primate communication.

Plecturocebus caquetensis (Primates: Pitheciidae)

Plecturocebus caquetensis (Defler, Bueno, and García, 2010) is a Neotropical primate commonly called the Caquetá titi monkey. It is small-sized with long, soft pelage of mixed coloration including grayish and buffy brown to agouti tones. It lacks the blackish or whitish band that is present on the forehead of closely related species. The tail is agouti-colored and slightly banded at its base. Endemic to the Amazonian region of Colombia with a distribution in areas near the eastern slopes of the Eastern and Central Cordillera of the Andes, P. caquetensis is confirmed in 104 localities in the departments of Cauca and Caquetá in Colombia. P. caquetensis is considered “Critically Endangered” (CR) by the International Union for Conservation of Nature and Natural Resources.