title: A wild Indo-Pacific bottlenose dolphin adopts a socially and genetically distant neonate.
abstract: Alloparental behaviour and adoption have been reported in many mammals and birds. Such behaviours are energetically costly, and their causes and functions remain unclear. We observed the adoption behaviour of a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus) near Mikura Island, Japan. A calf was seen with its mother on six observation days. Following the mother's death, the calf was observed with a sub-adult female on all 18 observation days from May to September 2012. On three days, the calf was observed swimming with this female in the suckling position and milk was seen leaking from the female's mammary slit. A five-year dataset revealed no significant social or kin relationships between the biological mother and allomother, indicating that kinship and social relationships did not play an important role in the observed adoption.
authors.affiliation: Department of Fisheries, Kindai University, 3327-204 Nakamachi, Nara, 631-8505, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Sakai
authors.affiliation: Department of Marine Biology and Sciences School of Biological Sciences, Tokai University, 5-1-1 Minamisawa, Minami-ku, Sapporo-shi, Hokkaido 005-8601, Japan.
authors.forename: Yuki F
authors.initials: YF
authors.lastname: Kita
authors.affiliation: Mikura Island Tourist Information Centre, Mikurajima-mura, Tokyo 100-1301, Japan.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Kogi
authors.affiliation: Faculty of Life and Environmental Sciences, Teikyo University of Science, 2525 Yatsusawa, Uenohara-shi, Yamanashi 409-0193, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Shinohara
authors.affiliation: Institute of Innovative Science and Technology, Tokai University, 3-20-1 Orido, Shimizu-ku, Shizuoka-shi, Shizuoka 424-8610, Japan.
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Morisaka
authors.affiliation: Department of Molecular Life Science, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara-shi, Kanagawa 259-1143, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiina
authors.affiliation: Wildlife Research Center, Kyoto University, 2-24 Tanaka-sekiden-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-8203, Japan.|Wildlife Genome Collaborative Research Group, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-shi, Ibaraki 305-8506, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Inoue-Murayama