Postnatal ontogeny of vocalization in the racoon dog, Nyctereutes procyonoides (Carnivora, Canidae) [Russian]

摘要

The vocalization was investigated in three litters of the racoon dog Nyctereutes procyonoides during the first 1.5 months of their life. An acoustic analysis was performed, and four periods were distinguished in the development of vocal behavior: neonatal, transitional, adaptation, and period of juvenile socialization. The vocalizations of the neonatal period includes a number of monotonous harmonic signals of high frequency within a definite range. The transitional period lasts from 8-12 to 20-25 days and is characterized by a higher diversity of signals. Some of signals are considered to be predecessors of the definitive signals: moan, growl, yawl, and squeal. The acclimatization period coincides with the time of emerging pups and is characterized by a considerable reduction of the vocal repertoire. A "voice breaking" phenomenon is a specific feature of the juvenile socialization period. A decrease of both basic and dominant frequency bandwidths was recorded in all the kinds of signals. The aggressive signals became dominant.