Statistical discrimination among vocalizations of individual squirrel monkeys (Saimiri sciureus).

Discriminant analysis was used to distinguish statistically between the chuck vocalizations of individual squirrel monkeys. A unique combination of values of six structural parameters characterized the chucks of each of 5 individuals, permitting reliable identification of sources of chuck vocalizations on the basis of chuck structures alone. Certain parameters were found to be nearly invariant within individual monkeys, while others were quite variable within and between individuals. We propose that this technique be used in retrospective classification of vocalizations by source, when observational identification of the sources of all vocalizations in a rapid sequence is not possible.