Behaviour 2019
Infant Presence Effects on Common Marmosets' Food-Associated Calls
Debora L. da Cruz1, Arrilton Araújo1, Judith M. Burkart2. 1Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil; 2Universität Zürich, Zürich, Zürich, Switzerland

Food-associated calls are widespread among primates. In cooperative breeders, these calls may indicate their high proactivity in sharing resources with other group members, especially at moments where infant care is necessary. We aimed at investigating how the presence of infants in a group affects food calling in wild Callithrix jacchus. Thus, we performed a series of experiments in which marmosets would encounter variable amounts and quality of food, both in periods where infants were present or not. We evaluated the latency to call, time feeding, and the number of calls emitted by the first animal to find the food. We found that male helpers had the most significant contribution to these behaviors. They decreased their latency to call and time feeding and increased call production when the group had immatures. This effect was independent of food quality and food quantity, indicating that males' behaviors were not driven solely by arousal to see food or by the increased risk of competition. Our results are consistent with C. jacchus proactive prosociality, with males’ prominent role in infant care, and finally, that marmoset vocal behaviors are consistent with intentionality.