Throat-to-Chest Behavior in Coimbra-Filho’s Titi Monkeys (Callicebus coimbrai) Is Potentially Associated with Olfactory Communication

Despite the evident socioecological importance, knowledge of olfactory communication in Neotropical primates is in its infancy. Thus, to aid our understanding, we report on and describe olfactory communication behavior in Endangered Coimbra-Filho’s titi monkey (Callicebus coimbrai) in two Atlantic Forest fragments in northeastern Brazil. We discuss our data using intragroup (communication and sexual attraction) and intergroup (territoriality) contexts. We systematically observed two titi monkey groups, one at Fazenda Trapsa (21 mo: 1513 h) and another at Mata do Junco (11 mo: 683 h). We recorded data on olfactory signals via all-occurrence sampling. We registered 14 olfaction-linked events in which the titi monkey pressed the right hand against the gular and sternal body regions and then wiped the palm repeatedly on the nearby branch. Adult males performed 11 events, whereas adult females performed the remaining 3. Most events associated with intragroup encounters had a sexual context. The events related to intergroup encounters appeared to be related to territorial defense. Our study provides the first evidence that Coimbra-Filho’s titi monkey uses olfactory communication for both intragroup and intergroup communication. Dominance, mate attraction, and territorial defense functions shown by Coimbra-Filho titi monkeys in their olfactory behaviors provide new insights into the socioecology of Callicebusand potential themes for future research.