Achievement

Trainee Fuller completed his dissertation on the vocal repertoire of adult male blue monkeys, focusing on acoustic structure, signal content, and adaptive function. He used observation (of caller and potential recipients), sound analysis and playback experiments. Calls, which were given exclusively by males resident in heterosexual groups, showed variation in the degree to which they were tightly associated with caller or environmental characteristics, and thus in how much "information" they contained. They also varied in the specificity of their function, with some overlap among calls that acted to repel rival males from the one-male groups, or as alarm calls. Applying cladistic methods more commonly used in morphological or genetic study, Fuller analyzed the structure, content and function of male calls in the repertoire to understand how selection for signal distinctiveness could drive the evolution of vocal repertoires, beginning with generalized disturbance-related vocalizations.