title: Which person is my trainer? Spontaneous visual discrimination of human individuals by bottlenose dolphins (Tursiops truncatus).
abstract: Bottlenose dolphins are known to use signature whistles to identify conspecifics auditorily. However, the way in which they recognize individuals visually is less well known. We investigated their visual recognition of familiar human individuals under the spontaneous discrimination task. In each trial, the main trainer appeared from behind a panel. In test trials, two persons (one was the main trainer) appeared from the left and right sides of the panel and moved along the poolside in opposite directions. Three of the four dolphins spontaneously followed their main trainers significantly above the level of chance. Subsequent tests, however, revealed that when the two persons wore identical clothing, the following response deteriorated. This suggests that dolphins can spontaneously discriminate human individuals using visual cues, but they do not utilize facial cues, but body area for this discrimination.
authors.affiliation: Primate Research Institute, Kyoto University, Kanrin 41-2, Inuyama, Aichi 484-8506 Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tomonaga
authors.affiliation: Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Uwano
authors.affiliation: Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan.
authors.forename: Sato
authors.initials: S
authors.lastname: Ogura
authors.affiliation: Graduate School of Humanities, Kwansei-Gakuin University, Uegahara, Nishinomiya, Hyogo 662-8501 Japan.
authors.forename: Hyangsun
authors.initials: H
authors.lastname: Chin
authors.affiliation: Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Dozaki
authors.affiliation: Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan.
authors.forename: Toyoshi
authors.initials: T
authors.lastname: Saito
keywords: Bottlenose dolphins; Comparative cognitive science; Individual recognition; Spontaneous visual discrimination