Vocal repertoire of free ‐ranging black howler monkeys’ (Alouatta pigra): Call types, contexts, and sex‐related contributions

This report provides the first detailed description of the vocal repertoire of black howler monkeys (Alouatta pigra), focusing on acoustic structures and contexts of emission of both loud and soft calls as well as on the contribution rate of males and females to the different call types. Three free‐ranging social groups of black howler monkeys living in Palenque National Park, Mexico were monitored. We identified twelve acoustically discriminable call types, eight described previously and four described here for the first time. A few call types were systematically emitted either isolated or during howling bouts, but most of them could be heard in both calling contexts. Three call types were emitted only by females and two only by males. Adult males’ call rates (for the seven shared call types) were higher than those of females but only when considering calls emitted within howling bouts. Our contextual analysis enabled us to divide call types into potential functional categories, according to their degree of contribution, to intra‐group versus inter‐group interactions and to neutral‐positive versus negative situations. We then discussed how socio‐ecological factors, notably sex differences in social behaviors, may explain the variability found in the vocal repertoire of this species and compared our findings with the literature on other primate species.

Source: American Journal of Primatology - January 16, 2017 Category: Psychiatry & Psychology Authors: Margarita Brise ño‐Jaramillo, Véronique Biquand, Alejandro Estrada, Alban Lemasson Tags: RESEARCH ARTICLE Source Type: research