Although the caviomorph rodents have a variety of communication patterns, the vocalizations of coypus have not been studied at all. It is not certain whether they communicate vocally or not. In this study, we video recorded coypus in captivity, extracted their calls from the data, and analyzed the frequency and duration of their vocalizations. Their vocalizations were classified into four major types of patterns (fa, kyu, boo, and gaa). In addition, observations during capture and treatment revealed that nutria have two other vocal patterns. Individual differences in vocal quality and tonation were also observed even in the same type calls. These results suggested that coypus engage in a variety of vocal communication for individual identification under natural conditions.
