Individuality of crow calls in male Japanese Green Pheasants Phasianus versicolor

摘要

The ecology of the Japanese Green Pheasant Phasianus versicolor should be elucidated for proper game bird population management. Individual discrimination is essential to elucidate its sociality. A method for individual discrimination that is reliable, feasible, and minimizes the burden to birds is needed for further research. Each characteristic distinguished by listening to their crow calls in the field seemed to be the clue to discriminate individuality of male pheasants. I visually analyzed sonograms, and observations of the shape, number, and distribution of high sound pressure level (SPL) frequencies distinguished differences of crow calls among birds. Then, I quantitatively analyzed sonograms by performing principal component analysis (PCA) using six parameters. The discriminative acoustic structure of crow calls were selected as six parameters. The crow calls of each bird were clustered closely and did not overlap with those of other birds. These analyses confirmed that there is more inter- than intra-individual variation in the acoustic structure of crow calls. Thus, I demonstrated both visually and quantitatively that the acoustic structure of crow calls discriminates individuality of male Japanese Green Pheasants. Individuality of male pheasants by the acoustic structure of crow calls will promote further research on various aspects of male pheasant society.