Individual vocal recognition in the black-headed spider monkey (Ateles fusciceps)

Individual vocal recognition – the ability to discriminate between individuals based on sound – is thought to be particularly useful for social species that regularly lose visual contact between group members. For instance, individuals living in a fission-fusion group that feed on patchily distributed food in a complex physical environment (e.g., dense forest) are likely to depend heavily on vocalisation to identify individuals that are good at finding food. Spider monkeys ( Ateles spp .) live in such environments and have distinctive individual contact calls ( whinnies ). We used a habituation-dishabituation playback-paradigm to investigate whether black-headed spider monkeys ( A. fusciceps ) are able to discriminate between female individuals in their group. We found that a group of captive spider monkeys was able to discriminate between individuals using those contact calls. Although many primate species have been found to have individual characteristics in their calls, this is one of the few direct experimental evidence of vocal recognition using a habituation-dishabituation paradigm.