What can virtual vocal tracts tell us about lemur communication?

Recent research emphasizes the importance of species-speci fic acoustic signals in primate vocal communication. We examine the potential of nasal tract resonance in generating these signals using anatomically based vocal tract computational modeling in lemurs. True lemurs ( Eulemur ) show a remarkable species diversity, and nasal vocalizations play a crucial role in their communication systems. The supralaryngeal cavities (glottal constriction, nasopharyngeal cavity, nasal chambers, and nostrils) of E. coronatus , E. rufus , E. rubriventer , E. macaco , and E. fulvus were approximated as fi xed-length concatenated tubes, variable in number according to nasal tract length and varying in size according to anatomical measurements. Formants extracted from the acoustic response of the computational models showed that differences in morphological features between lemur taxa determine the structural characters of their vocalizations.