Dear MARMAM Members, My co-authors and I are pleased to announce the publication of our new paper: Alcázar-Treviño, J., Johnson, M., Arranz, P., Warren, V.E., Pérez-González, C.J., Marques, T., Madsen, P.T. and Aguilar de Soto, N. 2021. Deep-diving beaked whales dive together but forage apart.* Proc. R. Soc. B.* *288*: 20201905. Abstract Echolocating animals that forage in social groups can potentially benefit from eavesdropping on other group members, cooperative foraging or social defence, but may also face problems of acoustic interference and intra-group competition for prey. Here, we investigate these potential trade-offs of sociality for extreme deep-diving Blainville′s and Cuvier's beaked whales. These species perform highly synchronous group dives as a presumed predator-avoidance behaviour, but the benefits and costs of this on foraging have not been investigated. We show that group members could hear their companions for a median of at least 91% of the vocal foraging phase of their dives. This enables whales to coordinate their mean travel direction despite differing individual headings as they pursue prey on a minute-by-minute basis. While beaked whales coordinate their echolocation-based foraging periods tightly, individual click and buzz rates are both independent of the number of whales in the group. Thus, their foraging performance is not affected by intra-group competition or interference from group members, and they do not seem to capitalize directly on eavesdropping on the echoes produced by the echolocation clicks of their companions. We conclude that the close diving and vocal synchronization of beaked whale groups that quantitatively reduces predation risk has little impact on foraging performance. The article is available at https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1905 Please, feel free to contact me via email to jalcazar@ull.edu.es if you have any questions regarding our study or if you want a PDF copy of the paper. Kind regards, Jesús Alcázar-Treviño -- Jesús Alcázar Treviño Doctorando FPU Grupo de Investigación BIOECOMAC Departamento de Biología Animal, Edafología y Geología Facultad de Ciencias - Sección Biología Avenida Astrofísico Francisco Sánchez, s/n Apartado 456 38200 La Laguna. S/C de Tenerife ull.es <https://www.ull.es/> ------------------------------ Aviso de confidencialidad <https://www.ull.es/informacion-sobre-web-institucional/#aviso-confidencialidad> Por favor, ten en cuenta el medio ambiente antes de imprimir este e-mail. Please, keep in mind the environment before printing this e-mail.