The role of extragroup encounters in a Neotropical, cooperative breeding primate, the common marmoset: a field playback experiment

摘要: In cooperatively breeding species, encounters with intruders may serve multiple functions, ranging from reaffirming group territory ranges to facilitating assessments for additional opportunities. While these distinctive events offer the opportunity investigate delicate balance of social dimensions within animal societies, their unpredictable occurrence makes witnessing and controlling in wild particularly challenging. Here we used a field playback approach simulate conspecific territorial incursions common marmosets, Callithrix jacchus, distinguish between three following nonmutually exclusive functions intergroup this species New World primate: defence, mate defence assessment For experiments, systematically broadcast species-typical long-distance contact calls (‘phees’) commonly interactions core periphery groups' territories using either male or female vocalizations. Consistent hypothesis, group's reaction was independent simulated intruder's sex response strength greater when stimulus area relative periphery. However, differences some facets marmosets' responses suggest that is not only potential function encounters. Mated males females started move first opposite sex, suggesting offered opportunities assess extrapair mated also showed piloerection towards intruders, which suggestive guarding. These data provide unique experimental evidence theory excursions by vertebrate are reflective known complexities marmoset sociobiology.