KINDAI UNIVERSITY


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SAKAI Mai

Profile

FacultyDepartment of Fisheries / Graduate School of Agriculture
PositionLecturer
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/1358-sakai-mai.html
URL
Mail
Last Updated :2020/09/30

Education and Career

Education

  •   1996 04  - 2000 03 , Tokyo University of Agriculture and Technology, Faculty of Agriculture
  •   2000 04  - 2002 03 , Tokyo University of Agriculture and Technology

Academic & Professional Experience

  •   2015 04 ,  - 現在, Lecturer, Department of Fisheries, Faculty of Agriculture, Kindai University
  •   2013 12 ,  - 2015 03 , Tokai University
  •   2012 04 ,  - 2013 11 , Kyoto University, Kyoto University
  •   2009 07 ,  - 2012 03 , Life Science Network, The University of Tokyo
  •   2008 01 ,  - 2008 03 , Post-Doctoral Fellow, Cetacean Unit, Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria
  •   2005 10 ,  - 2008 03 , JSPS research fellow (PD), Ocean Research Institute, The University of Tokyo

Research Activities

Research Areas

  • Life sciences, Marine/Aquatic life sciences
  • Life sciences, Animals: biochemistry, physiology, behavioral science
  • Humanities & social sciences, Cognitive sciences
  • Life sciences, Aquaculture

Research Interests

  • Tursiops

Published Papers

  • Fluid dynamic effects of small projections based on dorsal ridge tubercles of the finless porpoise, Yoshinobu INADA, Naoki TAMIYA, Maako MIYAKE, Tadamichi MORISAKA, Mai SAKAI, Ikuo WAKABAYASHI, Masahiko KASAMATSU, Yasuhiro UEKUSA, Journal of Biomechanical Science and Engineering, Journal of Biomechanical Science and Engineering, 12(3), Jul. 2017 , Refereed
  • 御蔵島に生息するミナミハンドウイルカ(Tursiops aduncus)の親子鑑定, 北夕紀, 村山美穂, 小木万布, 森阪匡通, 酒井麻衣, 椎名隆, DNA多型, DNA多型, 25(1), 52‐57, Jul. 2017 , Refereed
  • Analysis of Fluid Dynamic Effects between Adjacent Streamline Bodies, MIYAKE Maako, NARA Shotaro, INADA Yoshinobu, TAKAHASHI Shun, SAKAI Mai, MORISAKA Tadamichi, JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 65(1), 27 - 31, 2017 , Refereed
    Summary:Fluid dynamic effects between adjacent streamline bodies have a conspicuous role in drag reduction. One typical example is a dolphin drafting. When two dolphins such as a mother and a calf swim side by side, the calf seldom flaps its tail fin, indicating the calf utilizes the fluid dynamic force between the two bodies as a thrust. This force is generated by the Venturi effect. In this study, wind tunnel tests were conducted with two streamline bodies of different sizes that mimicked the mother and the calf dolphins to clarify the fluid dynamic effects between two bodies at various relative positions. In consequence, the increase of friction drag by the acceleration of flow between two bodies and the thrust generation by the Venturi effect were confirmed as well as the optimum position to maximize the thrust, indicating the possibility of effective design of airplanes with external appendages.
  • Detection of the Nighttime Distribution of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) around Mikura Island with Stationed Acoustic Buoys, MORISAKA Tadamichi, SAKAI Mai, SAKAI Mai, KOGI Kazunobu, 東海大学海洋研究所研究報告(Web), 東海大学海洋研究所研究報告(Web), (36), 1‐7 (WEB ONLY), Mar. 2015
  • Investigation of a Flow in Dolphin Drafting by Computational Fluid Dynamics, NARA Shotaro, MIYAKE Maako, TAKAHASHI Shun, INADA Yoshinobu, SAKAI Mai, MORISAKA Tadamichi, Proceedings. International Conference on Flow Dynamics (CD-ROM), Proceedings. International Conference on Flow Dynamics (CD-ROM), 12th, 152‐153, 2015
  • A Mobile Measurement System for Sound Source Level of Wild Dolphin Whistles, Morisaka Tadamichi, Sasaki Mai, Kogi Kazunobu, Shinke Tomio, Zin Thithi, Hama Hiromitsu, Memoirs of the Faculty of Engineering Osaka City University, Memoirs of the Faculty of Engineering Osaka City University, 54(54), 25 - 29, Dec. 2013
  • Mother-calf interactions and social behavior development in Commerson's dolphins (Cephalorhynchus commersonii), Mai Sakai, Tadamichi Morisaka, Mari Iwasaki, Yayoi Yoshida, Ikuo Wakabayashi, Atsushi Seko, Masahiko Kasamatsu, Shiro Kohshima, Journal of Ethology, Journal of Ethology, 31(3), 305 - 313, Sep. 2013 , Refereed
    Summary:Mother-calf interactions and the behaviors of mothers during separation from their calves were examined in four Commerson's dolphin (Cephalorhynchus commersonii) mother-calf pairs. Four infants were observed: 56.8 h over 30 days from birth to 263 days of age, 36.9 h over 20 days from birth to 149 days of age, 10.4 h over 3 days from birth to 2 days of age, and 15.0 h over 3 days from birth to 2 days of age. All four pairs shared common characteristics in the rate and frequencies of mother-calf interactions and the behaviors of mothers during the first week of life. After the first week, individual differences in changes in the frequency of each behavior were observed. The three behaviors considered representative of maternal care (parallel swimming, synchronous breathing, and body-to-body contact) were frequently performed in the first week; thereafter, the frequencies declined. Separate behaviors of mothers were infrequent during the first week and increased with an increase in infants' age. Bumping by infants increased with time, suggesting an increase in soliciting by calves and conflict between mothers and calves. The frequency of flipper-to-body rubbing also changed but in a complex manner, probably because the calves needed to learn how to perform this behavior from their mothers and because initiator and recipient of this behavior can be changed quickly. © 2013 Japan Ethological Society and Springer Japan.
  • Swim with Dolphins : Appropriate "Dolphin Image" for Sustainable Dolphin Swimming, MORISAKA TADAMICHI, SAKAI MAI, KOGI KAZUNOBU, ヒトと動物の関係学会誌, ヒトと動物の関係学会誌, (35), 23 - 27, Jul. 2013
  • ミナミハンドウイルカの識別個体から得た鳴音の音源音圧のバリエーション, MORISAKA TADAMICHI, SAKAI MAI, KOGI KAZUNOBU, SHINKE TOMIO, 霊長類研究, 霊長類研究, 29(0), 106 - 106, 2013
  • Reminiscences about mirror self-recognition, KUSAYAMA TAICHI, IKEDA YUZURU, IRIE NAOKO, CHIN KOJUN, TSUBOKAWA TATSUYA, TAKENO JUN'ICHI, SAKAI MAI, 動物心理学研究, 動物心理学研究, 62(1), 111-124 (J-STAGE) - 124, 2012
  • Reactions of Heaviside's dolphins to tagging attempts using remotely-deployed suction-cup tags, Mai Sakai, Leszek Karczmarski, Tadamichi Morisaka, Meredith Thornton, SOUTH AFRICAN JOURNAL OF WILDLIFE RESEARCH, SOUTH AFRICAN JOURNAL OF WILDLIFE RESEARCH, 41(1), 134 - 138, Apr. 2011 , Refereed
    Summary:Tagging attempts of Heaviside's dolphins (Cephalorhynchus heavisidii) using a remotely-deployed suction-cup tag were performed in Table Bay and St Helena Bay on the southwest coast of South Africa. The observed reactions of dolphins indicate that this tagging approach has negligible impacts on the dolphin behaviour and Heaviside's dolphins might be tagged with suction cup tags without adverse affects.
  • Swim speed and acceleration measurements of short-finned pilot whales (Globicephala macrorhynchus) in Hawai'i, Mai Sakai, Kagari Aoki, Katsufumi Sato, Masao Amano, Robin W. Baird, Daniel L. Webster, Gregory S. Schorr, Nobuyuki Miyazaki, MAMMAL STUDY, MAMMAL STUDY, 36(1), 55 - 59, Mar. 2011 , Refereed
  • Contact swimming behavior in wild Indo-Pacific bottlenose dolphins., Chaturaphatranon K, Sakai M, Kogi K, Kohshima S, Japan Ecological Society (2011/3, Sapporo), Japan Ecological Society (2011/3, Sapporo), 2011 , Refereed
  • Acoustic behavior of captive Commerson’s dolphins (Cephalorhynchus commersonii)., Yoshida Y, Morisaka T, Sakai M, Iwasaki M, Wakabayashi I, Seko A, Kasamatsu M, Fukuzawa H, Akamatsu T, Kohshima S, The 15th Kyoto University International Sym-posium: Biodiversity, Zoos and Aquariums “The Message from Animals” (2010/09, Nagoya)., The 15th Kyoto University International Sym-posium: Biodiversity, Zoos and Aquariums “The Message from Animals” (2010/09, Nagoya)., 2010 , Refereed
  • What can we study by observing captive animals : examples from studies on primates, dolphins, mouse deer and rhinoceros, KOHSHIMA Shiro, KOBAYASHI Hiromi, KUZE Noko, SEKIGUCHI Yusuke, ARAI Kazutoshi, SAKAI Mai, IWASAKI Mari, MATSUBAYASHI Hisashi, KIYASU Kaoru, Honyurui Kagaku (Mammalian Science), Honyurui Kagaku (Mammalian Science), 48(1), 159 - 167, Jun. 30 2008
  • Behavioural observations of bottlenose dolphins towards two dead conspecifics, Kathleen. M. Dudzinski, Mai Sakai, Keiko Masaki, Kazunobu Kogi, Toru Hishii, Michio Kurimoto, 29, 108 - 116, 2003 , Refereed
  • Emigration of Indo-Pacific bottlenose dolphins (Tursiops aduncus) from Mikura Island, Japan, Kimika Tsuji, Kazunobu Kogi, Mai Sakai, Tadamichi Morisaka, Aquatic Mammals, Aquatic Mammals, 43(6), 585 - 593, 2017 , Refereed
    Summary:© Aquatic Mammals 2017. Emigration of individual animals is an important biological phenomenon that depends on both populations and ecosystem attributes. Off Mikura Island, a long-term identification survey of individual Indo-Pacific bottlenose dolphins has been conducted since 1994 using an underwater video system. Between 1994 and 2014, 277 individual dolphins were identified by this survey, with 41 individuals emigrating from Mikura Island during this period. Adults emigrated significantly more often than younger age classes. The sex and age classes of emigrants in 2008 and 2010 (the years with the greatest amount of emigration) differed, suggesting that social relationships within a population may affect emigration. Emigrants were observed among the Izu Island Chain and in Chiba, Shizuoka, Mie, and Wakayama Prefectures. The greatest distance dolphins emigrated from Mikura Island was 390 km to Tanabe in Wakayama Prefecture. Some individuals were observed to have emigrated to several areas during the period. The most frequent destination was Toshima Island, one of the Izu Islands Chain, where emigrants have been observed to reproduce. Emigrant groups were composed exclusively of individuals from Mikura Island; there were no immigrants to the Mikura Island area during the 20-y period of observation, although six emigrants eventually returned to their original range. Future studies of social relationships and habitat use by emigrants will reveal more about the reasons dolphins leave their habitats.
  • A wild Indo-Pacific bottlenose dolphin adopts a socially and genetically distant neonate, Mai Sakai, Yuki F. Kita, Kazunobu Kogi, Masanori Shinohara, Tadamichi Morisaka, Takashi Shiina, Miho Inoue-Murayama, SCIENTIFIC REPORTS, SCIENTIFIC REPORTS, 6, 23902, Apr. 2016 , Refereed
    Summary: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.
  • A Simple and Non-invasive Measurement Method Important for Conserving Large Animals Underwater, Tadamichi Morisaka, Mai Sakai, Kazunobu Kogi, Hiromitsu Hama, GENETIC AND EVOLUTIONARY COMPUTING, VOL I, GENETIC AND EVOLUTIONARY COMPUTING, VOL I, 387, 105 - 111, 2016 , Refereed
    Summary:This paper shows how simple, non-invasive measurement method is important for conserving large animals living underwater. We have studied free-ranging wild Indo-Pacific bottlenose dolphins (Tursiops aduncus) around Mikura Island, Japan for about 15 years. We usually observe dolphin behavior and record acoustics underwater including photo-identification of every dolphins. Despite lots of video data, more basic information such as body size have lacked. In order to measure body size of the animals non-invasively, we used commercial measurement software which can measure the distance between two points on 3D photos by commercial 3D camera. Accuracy evaluation tests using a tape measure between 15 and 250 cm were conducted at the field site (Mikura Island) and the errors were within 5 % of the actual sizes. We successfully measured body size of 33 free-ranging wild dolphins. Mean absolute percentage error of the same individuals in different photos was within 4 % for dolphins. The average size of the adult dolphins was 249.6cm, which was the similar to the average actual size of 4 by-caught dolphins of the population (251.7 cm). We also opportunistically measured green turtles (Chelonia mydas) during our dolphin survey. Mean absolute percentage error of the same individuals in different photos was within 2 % for turtles. The average straight carapace length (SCL) of the 14 turtles was 48.3 cm (37.9 - 67.7 cm), which is much smaller than the adult green turtle length (80 - 111 cm). A simple measurement method is thus important to know the size of the large animals underwater, which indicates animal age and health condition, and are important for conserving these large animals.
  • Sound variation and function in captive Commerson's dolphins (Cephalorhynchus commersonii)., Yayoi M Yoshida, Tadamichi Morisaka, Mai Sakai, Mari Iwasaki, Ikuo Wakabayashi, Atsushi Seko, Masahiko Kasamatsu, Tomonari Akamatsu, Shiro Kohshima, Behavioural processes, Behavioural processes, 108, 11 - 9, Oct. 2014 , Refereed
    Summary:Commerson's dolphin (Cephalorhynchus commersonii), one of the smallest dolphin species, has been reported to produce only narrow-band high-frequency (NBHF) clicks and no whistles. To clarify their sound repertoire and examine the function of each type, we analysed the sounds and behaviour of captive Commerson's dolphins in Toba Aquarium, Japan. All recorded sounds were NBHF clicks with peak frequency >110kHz. The recorded click-trains were categorised into four types based on the changing pattern of their Inter-click intervals (ICI): Decreasing type, with continuously decreasing ICI during the last part of the train; Increasing type, with continuously increasing ICI during the last part; Fluctuating type, with fluctuating ICI; and Burst-pulse type, with very short and constant ICI. The frequency of the Decreasing type increased when approaching an object newly introduced to the tank, suggesting that the sound is used for echolocation on approach. The Burst-pulse type suddenly increased in front of the object and was often oriented towards it, suggesting that it was used for echolocation in close proximity to the object. In contrast, the Increasing type was rarely recorded during approach, but increased when a dolphin approached another dolphin. The Increasing and Burst-pulse types also increased when dolphins began social behaviours. These results suggest that some NBHF clicks have functions other than echolocation, such as communication.
  • Sound variation and function in captive Commerson's dolphins (Cephalorhynchus commersonii), Yayoi M. Yoshida, Tadamichi Morisaka, Mai Sakai, Mari Iwasaki, Ikuo Wakabayashi, Atsushi Seko, Masahiko Kasamatsu, Tomonari Akamatsu, Shiro Kohshima, BEHAVIOURAL PROCESSES, BEHAVIOURAL PROCESSES, 108, 11 - 19, Oct. 2014 , Refereed
    Summary:Commerson's dolphin (Cepholorhynchus commersonii), one of the smallest dolphin species, has been reported to produce only narrow-band high-frequency (NBHF) clicks and no whistles. To clarify their sound repertoire and examine the function of each type, we analysed the sounds and behaviour of captive Commerson's dolphins in Toba Aquarium, Japan. All recorded sounds were NBHF clicks with peak frequency >110 kHz. The recorded click-trains were categorised into four types based on the changing pattern of their Inter-click intervals (ICI): Decreasing type, with continuously decreasing ICI during the last part of the train; Increasing type, with continuously increasing ICI during the last part; Fluctuating type, with fluctuating ICI; and Burst-pulse type, with very short and constant ICI. The frequency of the Decreasing type increased when approaching an object newly introduced to the tank, suggesting that the sound is used for echolocation on approach. The Burst-pulse type suddenly increased in front of the object and was often oriented towards it, suggesting that it was used for echolocation in close proximity to the object. In contrast, the Increasing type was rarely recorded during approach, but increased when a dolphin approached another dolphin. The Increasing and Burst-pulse types also increased when dolphins began social behaviours. These results suggest that some NBHF clicks have functions other than echolocation, such as communication. (C) 2014 Elsevier B.V. All rights reserved.
  • Body contact and synchronous diving in long-finned pilot whales, Kagari Aoki, Mai Sakai, Patrick J. O. Miller, Fleur Visser, Katsufumi Sato, BEHAVIOURAL PROCESSES, BEHAVIOURAL PROCESSES, 99, 12 - 20, Oct. 2013 , Refereed
    Summary:Synchronous behavior, as a form of social interaction, has been widely reported for odontocete cetaceans observed at the sea surface. However, few studies have quantified synchronous behavior underwater. Using data from an animal-borne data recorder and camera, we described how a pair of deep-diving odontocetes, long-finned pilot whales, coordinated diving behavior. Diving data during overlapping periods of 3.7 h were obtained from two whales within a stable trio. The tagged whales made highly synchronous movements, and their dive durations differed only slightly (3 +/- 3 s). The pair of whales maintained a constant and narrow vertical separation (ca. 3 m) throughout synchronous dives. The overall fluking rate for the same travel speed during synchronous dives was virtually the same as that during asynchronous dives, suggesting that synchronous behavior did not affect locomotion effort. In addition, a possible affiliative behavior was recorded by the animal-borne camera: another individual appeared in 8% of the frames, both with and without body contact to the tagged whale. The primary type of body contact was flipper-to-body. Our study, the first on underwater synchronous behavior and body contact of pilot whales, highlights the utility of using animal-borne devices for enabling new insights into social interactions. (C) 2013 Elsevier B.V. All rights reserved.
  • Spontaneous Ejaculation in a Wild Indo-Pacific Bottlenose Dolphin (Tursiops aduncus), Tadamichi Morisaka, Mai Sakai, Kazunobu Kogi, Akane Nakasuji, Kasumi Sakakibara, Yuria Kasanuki, Motoi Yoshioka, PLOS ONE, PLOS ONE, 8(8), e72879, Aug. 2013 , Refereed
    Summary:Spontaneous ejaculation, which is defined as the release of seminal fluids without apparent sexual stimulation, has been documented in boreoeutherian mammals. Here we report spontaneous ejaculation in a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus), and present a video of this rare behavior. This is the first report of spontaneous ejaculation by an aquatic mammal, and the first video of this behavior in animals to be published in a scientific journal.
  • Do Porpoises Choose Their Associates? A New Method for Analyzing Social Relationships among Cetaceans, Mai Sakai, Ding Wang, Kexiong Wang, Songhai Li, Tomonari Akamatsu, PLOS ONE, PLOS ONE, 6(12), e28836, Dec. 2011 , Refereed
    Summary:Background: Observing and monitoring the underwater social interactions of cetaceans is challenging. Therefore, previous cetacean studies have monitored these interactions by surface observations. However, because cetaceans spend most of their time underwater, it is important that their underwater behavior is also continuously monitored to better understand their social relationships and social structure. The finless porpoise is small and has no dorsal fin. It is difficult to observe this species in the wild, and little is known of its sociality. Methodology/Principal Findings: The swim depths of 6 free-ranging finless porpoises were simultaneously recorded using a time-synchronized bio-logging system. Synchronous diving was used as an index of association. Two pairs, # 27 (an immature female estimated to be 3.5 years old) and # 32 (an adult male), # 28 (a juvenile male estimated to be 2 years old) and # 29 (an adult male), tended to participate in long periods of synchronized diving more frequently than 13 other possible pairs, indicating that the 4 porpoises chose their social partners. The adult males (# 32, # 29) tended to follow the immature female (# 27) and juvenile male (# 28), respectively. However, during synchronized diving, the role of an initiator often changed within the pair, and their body movements appeared to be non-agonistic, e. g., rubbing of bodies against one another instead of that on one-side, as observed with chasing and escaping behaviors. Conclusions/Significance: The present study employed a time-synchronized bio-logging method to observe the social relationships of free-ranging aquatic animals based on swimming depth. The results suggest that certain individuals form associations even if they are not a mother and calf pair. Long synchronized dives occurred when particular members were reunited, and this suggests that the synchronized dives were not a by-product of opportunistic aggregation.
  • Echolocation signals of Heaviside's dolphins (Cephalorhynchus heavisidii), Tadamichi Morisaka, Leszek Karczmarski, Tomonari Akamatsu, Mai Sakai, Steve Dawson, Meredith Thornton, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, 129(1), 449 - 457, Jan. 2011 , Refereed
    Summary:Field recordings of echolocation signals produced by Heaviside's dolphins (Cephalorhynchus heavisidii) were made off the coast of South Africa using a hydrophone array system. The system consisted of three hydrophones and an A-tag (miniature stereo acoustic data-logger). The mean centroid frequency was 125 kHz, with a -3 dB bandwidth of 15 kHz and -10 dB duration of 74 mu s. The mean back-calculated apparent source level was 173 dB re 1 mu Pa(p.-p.). These characteristics are very similar to those found in other Cephalorhynchus species, and such narrow-band high-frequency echolocation clicks appear to be a defining characteristic of the Cephalorhynchus genus. Click bursts with very short inter-click intervals (up to 2 ms) were also recorded, which produced the "cry" sound reported in other Cephalorhynchus species. Since inter-click intervals correlated positively to click duration and negatively to bandwidth, Heaviside's dolphins may adjust their click duration and bandwidth based on detection range. The bimodal distribution of the peak frequency and stable bimodal peaks in spectra of individual click suggest a slight asymmetry in the click production mechanism. (C) 2011 Acoustical Society of America. [DOI: 10.1121/1.3519401]
  • Fine-scale analysis of synchronous breathing in wild Indo-Pacific bottlenose dolphins (Tursiops aduncus), Mai Sakai, Tadamichi Morisaka, Kazunobu Kogi, Toru Hishii, Shiro Kohshima, BEHAVIOURAL PROCESSES, BEHAVIOURAL PROCESSES, 83(1), 48 - 53, Jan. 2010 , Refereed
    Summary:We quantitatively analysed synchronous breathing for dyads in Indo-Pacific bottlenose dolphins at Mikura Island. Tokyo, Japan. For most cases, we observed dyads swimming in the same direction (97%). in close proximity (i.e., less than 1.5 m) and with their body axes parallel as they breathed synchronously. Moreover, the pairs engaged in identical behaviour before and after the synchronous breathing episodes. These results suggest that the dolphins synchronize their movements, and that synchronous breathing is a component of "pair-swimming", an affiliative social behaviour. Same sex pairs of the same age class frequently engaged in synchronous breathing for adults and subadults, as well as mother-calf and escort-calf pairs. The distance between individuals during synchronous breathing for mother-calf pairs was less than for other pairs. The distance observed between individuals for female pairs was less than for male pairs. The time differences between each exhale for each of the two dolphins involved in synchronous breathing episodes for female pairs were smaller than for male pairs, and time differences for adult pairs were smaller than subadult pairs. These results suggest that age and sex class influenced the characteristics of this behaviour. (C) 2009 Elsevier B.V. All rights reserved.
  • Flipper rubbing behaviors in wild bottlenose dolphins (Tursiops aduncus), Mai Sakai, Toru Hishii, Shohei Takeda, Shiro Kohshima, MARINE MAMMAL SCIENCE, MARINE MAMMAL SCIENCE, 22(4), 966 - 978, Oct. 2006 , Refereed
    Summary:"Flipper rubbing" behavior was quantitatively analyzed in wild Indo-Pacific bottlenose dolphins (Tursiops aduncus) around Mikura Island, Tokyo, Japan. We observed two types of flipper rubbing: (1) F-B rubbing; one dolphin (Rubber) rubbed its flipper over various parts of a partner's (Rubbee) body, and (2) F-F rubbing; both dolphins rubbed each other's anterior flipper edge in alternating shifts. F-B rubbings tended to be initiated by the Rubbee and were terminated by the Rubber. The Rubbee often moved actively its body part that was in contact with the Rubber's flipper, and assumed side-up, upside-down, or other postures while the Rubber remained horizontal in most cases. These facts suggest that the Rubbee engaged in F-B rubbing more actively than the Rubber, and might receive some benefit from the frictional contact during F-B rubbing. Dolphins often switched their roles as Rubber and Rubbee between episodes of flipper rubbing bout. Adults and sub-adults exchanged F-B rubbing and F-F rubbing most often with individuals of the same sex in the same age class. F-B rubbing was frequent in mother-and-calf dyads. Our results suggest that flipper rubbing is an affiliative behavior which could be a quantitative measure of social relationships among individuals of this species in future studies.
  • Laterality of flipper rubbing behaviour in wild bottlenose dolphins (Tursiops aduncus): Caused by asymmetry of eye use?, M Sakai, T Hishii, S Takeda, S Kohshima, BEHAVIOURAL BRAIN RESEARCH, BEHAVIOURAL BRAIN RESEARCH, 170(2), 204 - 210, Jun. 2006 , Refereed
    Summary:To determine whether wild Indo-Pacific bottlenose dolphins (Tursiops aduncus) at Mikura Island, Japan, show asymmetry of eye or flipper use during a social behaviour, we investigated the laterality of flipper-to-body (F-B) rubbing, in which one dolphin ("rubber") rubs the body of another ("rubbee") with its flipper. We analysed 382 episodes of video-recorded F-B rubbings performed by identified individuals (N= 111 rubbers). F-B rubbing was conducted significantly more frequently with the left flipper than with the right flipper. The duration of F-B rubbings was also significantly longer with the left flipper than with the right flipper. Of 20 dolphins, nine individuals showed significant left-side bias as the rubber in this behaviour, whereas no dolphins showed significant right-side bias. The results indicate a population-level left-side bias of the rubber in F-B rubbing. An analysis of the swimming configurations during this behaviour suggests that the asymmetry in F-B rubbing was caused not only by the laterality of the rubber, but by a preference for use of the left eye in both dolphins during this behaviour. Dolphins used the left eye significantly more frequently than the right eye during the inquisitive behaviour, while they showed no significant bias in flipper use during the object-carrying behaviour. These facts also suggest that the asymmetry of F-B rubbing is caused by the preference for using the left eye. Significant left-side bias was observed only in F-B rubbings initiated by the rubbee, in which the rubbee determined its position during this behaviour. This suggests that this behavioural asymmetry was enhanced by the rubbees choosing the left side of the rubber to ensure better and longer rubs. (c) 2006 Elsevier B.V. All rights reserved.

Books etc

  • Ethology and Behavioral Ecology of Odontocetes, Bernd Würsig, Contributor, The Indo-Pacific Bottlenose Dolphin (Tursiops aduncus), Springer,   2019 , 9783030166632
  • Primates and Cetaceans: Field Research and Conservation of Complex Mammalian Societies (Primatology Monographs), Juichi Yamagiwa, Leszek Karczmarski, Contributor, Springer,   2013 11 , 4431545220
  • 生命科学の未解決問題―東大オープンキャンパス発, 石浦 章一, 西村書店,   2012 08 , 4890136800
  • Advances in Sociology Research, Jared A. Jaworski, Nova Science Publishers,   2012 02 01 , 1613245157

Conference Activities & Talks

  • 野生ミナミハンドウイルカにおける採餌行動の水中観察による分析, 高橋力也, 酒井麻衣, 小木万布, 森阪匡通, 大泉宏, 日本哺乳類学会大会プログラム・講演要旨集,   2019 09 15
  • 飼育ハンドウイルカにおける表皮中コルチゾールのストレス指標としての有用性の評価, 鬼頭拓也, 山本知里, 山本知里, 柏木伸幸, 大塚美加, 喜納泰斗, 鈴木美和, 友永雅己, 酒井麻衣, 日本水産学会大会講演要旨集,   2019 03 26
  • 野生ミナミハンドウイルカにおける餌生物の分析:採餌行動の観察と胃内容物の情報を用いて, 高橋力也, 酒井麻衣, 小木万布, 森阪匡通, 大泉宏, 日本水産学会大会講演要旨集,   2019 03 26
  • 飼育下ハナゴンドウにおけるジャンプの分析, 酒井夏生, 桐畑哲雄, 浅見優希菜, 酒井麻衣, 日本哺乳類学会大会プログラム・講演要旨集,   2018 09 08
  • 野生ミナミハンドウイルカ(Tursiops aduncus)における社会的性行動, 宮西葵, 小木万布, 酒井麻衣, 日本哺乳類学会大会プログラム・講演要旨集,   2018 09 08
  • 飼育下ハナゴンドウにおけるジャンプの分析, 酒井夏生, 桐畑哲雄, 浅見優希菜, 酒井麻衣, 日本動物行動学会大会発表要旨集,   2018
  • 協力課題におけるハンドウイルカのパートナーの認識, 山本知里, 柏木伸幸, 大塚美加, 西村佳織, 酒井麻衣, 友永雅己, 日本動物行動学会大会発表要旨集,   2017 12
  • 飼育下ハナゴンドウの社会行動:コドモ個体を中心とした分析, 酒井夏生, 桐畑哲雄, 酒井麻衣, 日本水産学会大会講演要旨集,   2017 03 26
  • 飼育ハンドウイルカにおける表皮中コルチゾールの測定の試み, 鬼頭拓也, 山本知里, 柏木伸幸, 大塚美加, 中村政之, 大塚ちはる, 鈴木美和, 友永雅己, 酒井麻衣, 日本水産学会大会講演要旨集,   2017 03 26
  • 並泳する2頭のイルカの間に働く流体力学的な相互作用の分析, 三宅真亜子, 丸島侑紀奈, 崔磨美, 稲田喜信, 高橋俊, 酒井麻衣, 森阪匡通, 日本機械学会関東支部総会・講演会講演論文集(CD-ROM),   2017 03 15
  • 飼育下ハナゴンドウの社会行動:コドモ個体を中心とした行動分析, 酒井夏生, 桐畑哲雄, 酒井麻衣, 日本動物行動学会大会発表要旨集,   2017
  • 飼育下シャチにおける社会行動と個体間関係の分析, 中野智仁, 漁野真弘, 日登弘, 勝俣浩, 荒井一利, 酒井麻衣, 日本動物行動学会大会発表要旨集,   2017
  • ハンドウイルカ属における社会的性行動, 宮西葵, 小木万布, 酒井麻衣, 日本動物行動学会大会発表要旨集,   2017
  • イルカの水中社会性:ふれあいと同調, 酒井麻衣, 日本哺乳類学会大会プログラム・講演要旨集,   2016 09 23
  • 御蔵島ミナミハンドウイルカの出産季節性に関する統計的研究, 片山佳実, 小木万布, 酒井麻衣, 森阪匡通, 北門利英, 日本水産学会大会講演要旨集,   2016 09 08
  • 野生ミナミハンドウイルカ体表面のダルマザメ食痕, 田中美帆, 森阪匡通, 酒井麻衣, 小木万布, 吉田智弘, 日本水産学会大会講演要旨集,   2016 03 26
  • 御蔵島周辺に生息するミナミハンドウイルカ(Tursiops aduncus)の呼吸同調行動の発達:0歳齢から5歳齢まで, 田島夏子, 酒井麻衣, 酒井麻衣, 森阪匡通, 小木万布, 武田庄平, 日本水産学会大会講演要旨集,   2015 03 27
  • ミナミハンドウイルカにおける接触行動と社会的性行動の予備的研究, 田中美帆, 酒井麻衣, 酒井麻衣, 森阪匡通, 小木万布, 日本水産学会大会講演要旨集,   2015 03 27
  • ネズミイルカの背鰭に見られる突起構造を参考にしたラフネスの流体力学的な効果, 稲田喜信, 田宮直樹, 三宅真亜子, 浅場裕伸, 宍倉里沙, 土屋優奈, 山本将大, 森阪匡通, 酒井麻衣, 植草康浩, 小林万里, 田口美緒子, 飛行機シンポジウム講演集(CD-ROM),   2015
  • 野生ミナミハンドウイルカにおける養子とりの観察, SAKAI MAI, KITA YUKI, KOGI KAZUNOBU, SHINOHARA MASANORI, MORISAKA TADAMICHI, SHIINA TAKASHI, INOE(MURAYAMA) MIHO, 日本哺乳類学会大会プログラム・講演要旨集,   2014 09 04
  • 野生イルカの非侵襲的な体長推定の試み, MORISAKA TADAMICHI, SAKAI MAI, KOGI KAZUNOBU, HAMA HIROMITSU, 日本哺乳類学会大会プログラム・講演要旨集,   2014 09 04
  • 人の接近時に生じるミナミハンドウイルカ(Tursiops aduncus)の防衛行動に関する研究, SAKAKIBARA KASUMI, SAKAI MAI, MORISAKA TADAMICHI, OGI KAZUYOSHI, KOSHIMA SHIRO, 日本水産学会大会講演要旨集,   2014 03 27
  • 御蔵島ミナミバンドウイルカにおける血縁解析, KITA YUKI, MURAYAMA MIHO, SHINOHARA MASANORI, SAKAI MAI, MORISAKA TADAMICHI, KOGI KAZUNOBU, SHIINA TAKASHI, 日本水産学会大会講演要旨集,   2014 03 27
  • 野生イルカはどのように水中遊泳者に接近するか?, SAKAKIBARA KASUMI, KOGI KAZUNOBU, SAKAI MAI, MORISAKA TADAMICHI, KARASHIMA SHIRO, 日本動物行動学会大会発表要旨集,   2014
  • 飼育ハンドウイルカにおける接触行動の左右性, SAKAI MAI, YAMAMOTO CHIRI, ARAI KAZUTOSHI, NAKAHATA KATSUMI, KOSHIMA SHIRO, 日本水産学会大会講演要旨集,   2013 03 26
  • ミナミハンドウイルカの識別個体から得た鳴音の音源音圧, MORISAKA TADAMICHI, SAKAI MAI, OGI KAZUNOBU, 日本水産学会大会講演要旨集,   2013 03 26
  • イロワケイルカにおける接触を伴う社会行動の左右性, SAKAI MAI, MORISAKA TADAMICHI, WAKABAYASHI IKUO, SEKO ATSUSHI, KASAMATSU MASAHIKO, 日本動物行動学会大会発表要旨集,   2012
  • ハンドウイルカ属における接触行動の比較研究, SAKAI MAI, OGI KAZUNOBU, ARAI KAZUTOSHI, KOSHIMA SHIRO, 日本水産学会大会講演要旨集,   2011 03 27
  • CONTACT SWIM BEHAVIORS IN WILD BOTTLENOSE DOLPHINS, KANANG Chaturaphatranon, SAKAI Mai, KOHSHIMA Shiro, 日本生態学会大会講演要旨集,   2011 03 08
  • Studies on social behavior in dolphins, SAKAI MAI, NSUGAF,   2011 01 15
  • イルカの社会的毛づくろい:バンドウイルカとミナミハンドウイルカの比較, SAKAI MAI, KOGI MAMPU, ARAI KAZUTOSHI, KOSHIMA SHIRO, 日本動物心理学会大会プログラム,   2011
  • イルカの社会行動, SAKAI MAI, 日本水産学会大会講演要旨集,   2010 09 22
  • バイオロギングシステムを用いた水棲動物研究 16 スナメリにおける同調潜水の分析, SAKAI MAI, O CHO, O KOKUYU, RI SHOKAI, AKAMATSU, TOMONARI, 日本水産学会大会講演要旨集,   2010 03 26
  • 伊豆島島周辺海域でのミナミハンドウイルカの発見, MORISAKA TADAMICHI, SEKIGUCHI YUSUKE, SHIRAKIHARA MIKI, SHINOHARA MASANORI, KOGI KAZUNOBU, TAKANAWA NANA, MASAKI KEIKO, MORI KYOICHI, TSUTSUI HIROTOSHI, UCHIKOMI NAYUKO, SAKAI MAI, KOSHIMA SHIRO, YOSHIOKA MOTOI, 日本水産学会大会講演要旨集,   2010 03 26
  • 海中雑音がイルカの音声と群れに与える影響, MORISAKA TADAMICHI, SAKAI MAI, SHIRAKIHARA MIKI, MORI KYOICHI, OGI MAHO, 日本生態学会大会講演要旨集,   2010 03 15
  • 飼育下スナメリの接触を伴う社会行動, NOGUCHI KAYAKO, YOSHIDA YAYOI, SAKAI MAI, OKAMURA HIROMI, ISHIBASHI TOSHIAKI, TAKADA KOJI, KOSHIMA SHIRO, 日本動物行動学会大会発表要旨集,   2009
  • 御蔵島のミナミハンドウイルカのメスの社会関係について, UEDA NAHOKO, KOGI KAZUNOBU, SAKAI MAI, TAKANAWA NANA, MORISAKA TADAMICHI, KARUSUMARUSUKI RESHEKKU, 日本動物行動学会大会発表要旨集,   2008
  • 野生ミナミハンドウイルカの社会行動~一緒に泳ぐ行動について~, MIYAZAKI YUKI, SAKAI MAI, KOGI KAZUNOBU, KOSHIMA SHIRO, 日本動物行動学会大会発表要旨集,   2008
  • バイオロギングシステムを用いた水棲動物研究 3―スナメリの呼吸同調の分析―, SAKAI MAI, O TEI, O KOKUYU, RI SHOKAI, AKAMATSU, TOMONARI, 日本水産学会大会講演要旨集,   2007 03 28
  • うるさい海中でのイルカのコミュニケーション音, MORISAKA MASAYUKI, SAKAI MAI, MORI KYOICHI, SHIRAKIHARA MIKI, OGI KAZUNOBU, 日本動物行動学会大会発表要旨集,   2007
  • 飼育下イロワケイルカCephalorhynchus commersoniiの音声行動, YOSHIDA YAYOI, MORISAKA MASAYUKI, SAKAI MAI, IWASAKI MARI, WAKABAYASHI IKUO, SEKO ATSUSHI, KASAMATSU MASAHIKO, AKAMATSU TOMONARI, KOSHIMA SHIRO, 日本動物行動学会大会発表要旨集,   2007
  • 野生ミナミハンドウイルカの死児運搬, SAKAI MAI, UEDA NAHOKO, MORISAKA MASAYUKI, OGI KAZUYOSHI, HISHII TOORU, 日本動物行動学会大会発表要旨集,   2007
  • イロワケイルカ(Cephalorhynchus commersonii)の新生児における社会行動の発達, SAKAI MAI, MORISAKA TADAMICHI, IWASAKI MARI, YOSHIDA YAYOI, WAKABAYASHI IKUO, SEKO ATSUSHI, KASAMATSU MASAHIKO, KOSHIMA SHIRO, 日本動物行動学会大会発表要旨集,   2006
  • 野生ミナミハンドウイルカにおける呼吸同調の行動分析, SAKAI MAI, HISHII TOORU, KOSHIMA SHIRO, 日本水産学会大会講演要旨集,   2005 04 01
  • イルカは左利き?再考:野生ハンドウイルカにおける社会行動の左右差, SAKAI MAI, HISHII TOORU, TAKEDA SHOHEI, KOSHIMA SHIRO, 日本動物行動学会大会発表要旨集,   2004
  • シロイルカは数がわかるか 1と2の弁別の基礎的研究, SAKAI MAI, MURAYAMA TSUKASA, MURAMATSU MASAYUKI, 日本水産学会大会講演要旨集,   2000 04 01

Misc

  • Kinship analysis of Indo-pacific bottlenose dolphin (Tursiops aduncus) around Mikura Island in Japan., Kita Y F, Inoue-Murayama M, Kogi K, Morisaka T, Sakai M, S Takashi, SMM2017the 22nd Biennial Conference on the Biology of Marine Mammals 10月22-27日 Halifax World Trade and Convention Centre(Nova Scotia, Canada),   2017
  • Swim with Dolphins : Appropriate "Dolphin Image" for Sustainable Dolphin Swimming, 森阪 匡通, 酒井 麻衣, 小木 万布, ヒトと動物の関係学会誌 = Japanese journal of human animal relations, 35, 23, 27,   2013 07 , http://id.ndl.go.jp/bib/024761555
  • ミナミハンドウイルカの生態 御蔵島周辺に生息するミナミハンドウイルカの生息場所利用, NAKASUJI AKANE, MORISAKA TADAMICHI, SAKAI MAI, KOGI KAZUNOBU, HORI MICHIO, 月刊海洋, 45, 5, 293, 302,   2013 05 01 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201302222256726391
  • ミナミハンドウイルカの生態 ミナミハンドウイルカにおける社会と行動の研究の動向, SAKAI MAI, 月刊海洋, 45, 5, 267, 276,   2013 05 01 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201302236203971174
  • ミナミハンドウイルカの生態 伊豆鳥島のミナミハンドウイルカ, MORISAKA TADAMICHI, SEKIGUCHI YUSUKE, SHIRAKIHARA MIKI, SHINOHARA MASANORI, KOGI KAZUNOBU, TAKANAWA NANA, MASAKI KEIKO, MORI KYOICHI, TSUTSUI HIROTOSHI, UCHIKOMI MIYUKO, SAKAI MAI, KOSHIMA SHIRO, YOSHIOKA MOTOI, 月刊海洋, 45, 5, 232, 238,   2013 05 01 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201302285039811250
  • ミナミハンドウイルカの生態 御蔵島のミナミハンドウイルカのホイッスルにおける個体識別の可能性, TANAKA MIKU, MORISAKA TADAMICHI, KOGI KAZUNOBU, SAKAI MAI, MORI KYOICHI, 月刊海洋, 45, 5, 288, 292,   2013 05 01 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201302290620102507
  • A green turtle (Chelonia mydas) feeding on a jellyfish around Mikura Island, Tokyo, Japan, 森阪 匡通, 酒井 麻衣, 小木 万布, 久保田 信, 亀崎 直樹, うみがめニュースレター, 89, 89, 15, 16,   2011 12 31 , http://hdl.handle.net/2433/197423
  • 2. Studies on social behavior in dolphins, Mai Sakai, Nippon Suisan Gakkaishi (Japanese Edition), 77, 1, 118,   2011 , 10.2331/suisan.77.118, http://ci.nii.ac.jp/naid/10027411782
  • イルカの社会行動, 酒井麻衣, 日本水産学会大会講演要旨集, 2010, 149,   2010 09 22 , http://jglobal.jst.go.jp/public/201002250868408943
  • 伊豆島島周辺海域でのミナミハンドウイルカの発見, 森阪匡通, 関口雄祐, 白木原美紀, 篠原正典, 小木万布, 高縄奈々, 正木慶子, 森恭一, 筒井浩俊, 打込南友子, 酒井麻衣, 幸島司郎, 吉岡基, 日本水産学会大会講演要旨集, 2010, 93,   2010 03 26 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201002231283963793
  • 海中雑音がイルカの音声と群れに与える影響, 森阪匡通, 酒井麻衣, 白木原美紀, 森恭一, 小木万布, 日本生態学会大会講演要旨集, 57th, 221,   2010 03 15 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201002207363570620
  • Pulse sounds of captive commerson’s dolphin., Yoshida Y, Morisaka T, Sakai M, Iwasaki M, Wakabayashi I, Seko A, Kasamastu M, Akamastu T, Kohshima S, The 5th Animal Sonar Symposium (2009/09, Kyoto),   2009 , Refereed
  • Variation and function of the sounds produced by captive Commerson’s dolphins (Cephalorhynchus commersonii), Yoshida Y, Morisaka T, Sakai M, Iwasaki M, Wakabayashi I, Seko A, Kasamatsu M, Fukuzawa H, Akamatsu T, Kohshima S, 18th Biennial Conference on the Biology of Marine Mammals (2009/10, Quebec),   2009 , Refereed
  • 生理,行動,分子から見た海棲哺乳類の生物学―最近の話題から―野生鯨類の社会行動に関する研究, SAKAI MAI, 月刊海洋, 40, 10, 585, 589,   2008 12 01 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=200902278039633205
  • Studies on social behavior of wild cetaceans, 酒井 麻衣, Kaiyo monthly, 40, 10, 585, 589,   2008 12 , http://ci.nii.ac.jp/naid/40016355705
  • Pulse sounds of captive Commerson’s dolphins (Cephalorhynchus commersonii), Yoshida Y, Morisaka T, Sakai M, Iwsaki M, Wakabayashi I, Seko A, Kasamastu M, Akamastu T, Kohshima S, International Conference on Acoustic Communication by Animals (2008/08, Oregon).,   2008 , Refereed
  • うるさい海中でのイルカのコミュニケーション音, 森阪匡通, 酒井麻衣, 森恭一, 白木原美紀, 小木万布, 日本動物行動学会大会発表要旨集, 26th, 68,   2007 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200902291353133647

Research Grants & Projects

  • Ministry of Education, Culture, Sports, Science and Technology, Grants-in-Aid for Scientific Research(若手研究(スタートアップ), 研究活動スタート支援), Studies on communications using contact and synchrony: from the view of dolphins, Two social behaviors, physical contact and synchrony of odontocetes were studied by using underwater observation of wild dolphins, observation of captive dolphins and biologging system. The results suggest that synchronous breathing is a component of an affiliative social behaviour in Indo-Pacific bottlenose dolphins. The results also show the differences in social contact with flipper of Delphinidae and that of Phocaenidae. Finless porpoises seemed to have undeveloped social structure in previous study, however, our results suggest that they form associations with particular individuals.
  • Ministry of Education, Culture, Sports, Science and Technology, Grants-in-Aid for Scientific Research(基盤研究(B)), Studies on Distribution and Biology of Indo-Pacific bottlenose dolphins (Tursiops aduncus) around Japan, Distribution, genetic relationship among local populations, behavior and reproductive physiology were studied for the conservation of Indo-Pacific bottlenose dolphins around Japan. In Amami Is.area where the species was first reported in Japan, more than 50 dolphins were photo-identified by boat-based surveys. A population was found around Torishima Is., Tokyo for the first time and it is genetically related to Mikura and Ogasawara populations. Frequency of social behaviors of the wild dolphins around Mikura Is.varied with sex and developmental stage. Male reproductive activity was higher in spring to fall seasons.