Age and social affinity effects on contact call interactions in free-ranging spider monkeys

• DOI: 10.1007/s00265-018-2615-2
• Publication Date: 2018-12-07T06:50:23Z
• Authors: M. Briseno-Jaramillo; G. Ramos-Fernández; T. M. Palacios-Romo; J. R. Sosa-López; A. Lemasson
• Keywords: 0106 biological sciences; Call exchanges; New World monkeys; [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior; [SCCO.NEUR]Cognitive science/Neuroscience; [SCCO.NEUR] Cognitive science/Neuroscience; [SDV.NEU.PC] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior; [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences; Vocal communication; 01 natural sciences; Vocal learning; [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; Acoustic matching; [SDV.BA.ZV] Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; [SDV.NEU.SC] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences

Nonhuman primates’ vocal repertoire has shown little plasticity, with immatures producing adult-like acoustic structures. Yet, the use of different call types shows a degree of socially dependent flexibility during development. In several nonhuman primate species, group members exchange contact calls respecting a set of social and temporal rules that may be learned (e.g., overlap avoidance, turn-taking, social selection of interacting partners, and call type matching). Here, we study the use of contact calls in free-living adult and immature (old and young) spider monkeys (Ateles geoffroyi). We focused our study in two contact call types of the species’ repertoire: whinnies and high-whinnies. Our results suggest that individuals in all age classes produced both call types, with immatures producing less frequently the whinny call type. Immature individuals exchanged calls less often than adults, although their contribution increased with age. Conversely, mature individuals regulated their emissions by (1) exchanging more calls with their preferred affiliative partner and (2) matching the call type, while immatures did not. Our results show that contact call usage changes during development and suggest that adult rules might be learned. We argue that call matching is a “conversational rule” that young individuals acquire with apparent call-type-dependent variations during development. Our findings support the idea that social factors influence vocal development in nonhuman primates.