On 21st June 2026, Rina Keboushi (M2) from the Shimada Research Group, Department of Systems Innovation, received Best Oral Presentation Award at the 36th Annual Meeting of the Cetology Study Group of Japan.
Best Oral Presentation Award, the 36th Annual Meeting of the Cetology Study Group of Japan
This award recognizes the most outstanding oral presentation by students at the 36th Annual Meeting of the Cetology Study Group of Japan (https://sites.google.com/view/cetoken36/), which focuses on marine mammals, including cetaceans.
About awarded research
In the presentation titled “The social network structure of humpback whales in the Okinawa breeding grounds” (Rina Keboushi (Univ. Tokyo), Nozomi Kobayashi (OCF*), Haruna Okabe (OCF*), Sachie Ozawa (OCF*), and Takashi Shimada (Univ. Tokyo)), we analyzed the social relationships of humpback whales (Megaptera novaeangliae) observed around Okinawa. Using individual identification data collected through visual surveys, we built a social network based on how often individual whales were seen together in the same group. While humpback whales are known for gathering in breeding areas, little research has explored how they are socially connected in these environments. Our study aims to better understand their breeding strategies by applying mathematical and statistical methods. In this presentation, we reported that males were disproportionately represented among “hub” individuals with exceptionally high degree, and that the network structure exhibited characteristics consistent with the “strength of weak ties” theory observed in human societies. These findings suggest that the reproductive strategy of this species is reflected in its social network structure. In future work, we plan to incorporate temporal information to evaluate the stability and dynamics of the network structure and to develop mathematical models that more explicitly describe reproductive strategies. (*OCF: Okinawa Churashima Foundation)
I received valuable feedback from cetacean researchers and marine mammal experts from across Japan, making the meeting an extremely rewarding experience. I am truly honored and delighted to receive this award that I have admired since my undergraduate years. I would like to express my sincere gratitude to Professor Shimada for continuous guidance, as well as to all members of our laboratory. I am also deeply thankful to Kobayashi, Okabe, and Ozawa of the Okinawa Churashima Foundation for offering opportunities for collaborative research and for sharing their invaluable insights into humpback whale ecology.
Wenxin Cao (D2), Department of Chemical System Engineering, received Excellence Award for Student Presentation at the 36th annual meeting of the Japanese Society for Alternatives to Animal Experiments
Mitsuki Nagaura (M2), Department of Bioengineering, received Excellence Oral Presentation Award at 35th Discussion Group of Polymer Gels
