Duetting Patterns of Titi Monkeys (Primates, Pitheciidae: Callicebinae) and Relationships with Phylogeny

• Published in: Animals (Basel) Vol. 8; no. 10; p. 178
• Main Authors: Adret, Patrice, Dingess, Kimberly A, Caselli, Christini B, Vermeer, Jan, Martínez, Jesus M, Luna Amancio, Jossy C, van Kuijk, Silvy M, Hernani Lineros, Lucero M, Wallace, Robert B, Fernandez-Duque, Eduardo, Di Fiore, Anthony
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.10.2018; MDPI
• Subjects: Acoustic properties; Acoustics; Analysis; Book publishing; Broadband; Callicebus; Cheracebus; conservation; Discoloration; Discriminant analysis; Endangered populations; Incoherence; Monkeys; Monkeys & apes; Narrowband; Phylogeny; Plecturocebus; Primates; Social aspects; Social discrimination learning; Spectral analysis; Spectrum analysis; Syllables; taxonomy; vocal communication; Vocalization behavior; Brazil; Ecuador; United Kingdom; Bolivia; conservation; taxonomy; Cheracebus; Plecturocebus; Callicebus; vocal communication
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani8100178

Long-range vocal communication in socially monogamous titi monkeys is mediated by the production of loud, advertising calls in the form of solos, duets, and choruses. We conducted a power spectral analysis of duets and choruses (simply "duets" hereafter) followed by linear discriminant analysis using three acoustic parameters-dominant frequency of the combined signal, duet sequence duration, and pant call rate-comparing the coordinated vocalizations recorded from 36 family groups at 18 sites in Bolivia, Peru and Ecuador. Our analysis identified four distinct duetting patterns: (1) a donacophilus pattern, , characteristic of , , , and ; (2) a moloch pattern comprising , , , and ; (3) a torquatus pattern exemplified by the duet of ; and (4) the distinctive duet of , a putative member of the donacophilus group, which is characterized by a mix of broadband and narrowband syllables, many of which are unique to this species. We also document a sex-related difference in the bellow-pant phrase combination among the three taxa sampled from the moloch lineage. Our data reveal a presumptive taxonomic incoherence illustrated by the distinctive loud calls of both and within the donacophilus lineage, . The results are discussed in light of recent reassessments of the callicebine phylogeny, based on a suite of genetic studies, and the potential contribution of environmental influences, including habitat acoustics and social learning. A better knowledge of callicebine loud calls may also impact the conservation of critically endangered populations, such as the vocally distinctive Peruvian endemic, the San Martin titi, .