Categorical and semantic perception of the meaning of call-types in zebra finches

Vocal communication in social animals involves the production and perception of various calls that ethologists categorize into call-types, based on their acoustical structure and the behavioral context of production. Whether animals perceive these categories and associate distinct meanings to them remains unknown. The zebra finch, a gregarious songbird, uses approximately 11 call-types to communicate hunger, danger, social conflict, and establish social contact and bonding. Using auditory discrimination tasks, we show that the birds discriminate and categorize all the call-types in their vocal repertoire. In addition, systematic errors were more frequent between call-types used in similar behavioral contexts than could be expected from their acoustic similarity. Thus, zebra finches organize their calls into categories and create a mental representation of the meaning of these sounds.