Dear all, I and my colleagues are pleased to share here three recent publications related to marine mammals. Two are opinion articles published in Science and in Nature, where no Abstracts are available for this type of article so copies can be requested to filipe.alves@mare-centre.pt Filipe Alves, Massimiliano Rosso, Songhai Li, Douglas P. Nowacek (2022) A sea of possibilities for marine megafauna. Science 375(6579): 391-392. DOI:10.1126/science.abn6022 Filipe Alves, João G. Monteiro, Paulo Oliveira, João Canning-Clode (2022) Portugal leads with Europe’s largest marine reserve. Nature 601: 318. DOI:10.1038/d41586-022-00093-8 The third publication is open-access and is about the social structure of an elusive deep-diving predator, the Blainville's beaked whale, based on a comprehensive analysis from long-term photo-ID data collected in Madeira Island. Badenas A #, Dinis A, Ferreira R, Sambolino A, Hamard E, Berninsone LG, Fernandez M, Alves F #* (2022) Behavioural Ecology Traits of Elusive Deep-Diver Whales Unravel a Complex Social Structure Influenced by Female Philopatry and Defence Polygyny. Front. Mar. Sci. 9:809902. DOI:10.3389/fmars.2022.809902 # These authors contributed equally.* Corresponding author. AbstractKnowledge of the role of individual associations has provided an insightful understandingof the structures of animal societies, especially in highly social mammals such asprimates. Yet, this is unbalanced towards marine mammals, particularly to beakedwhales, due to their elusive nature. In addition, information on the fundamental driversof the social structure of these deep-diving animals is still scarce. Here, the hypothesisof female defence polygyny was tested in Blainville’s beaked whales (Mesoplodondensirostris) and discussed within the context of marine and terrestrial organismsdisplaying similar patterns, by (i) estimating residency times to obtain information onthe movements into and out of the area, (ii) analysing social networks to assessindividual association metrics, (iii) measuring the strength of the associations to assessthe existence of preferred or avoided relationships among individuals, and (iv) modellingdifferent social structures to address temporal patterns in social relationships. Using a 9-year photographic dataset derived from the pelagic habitat, individual associations wereinferred based on likelihood techniques. This approach allowed to infer on the species’social structure in relation to age class, sex, residency status, and spatio-temporalpatterns, which can be a good practice to be applied for other taxa. Heterogeneityin capture probability and residency times was observed between age-sex classes, withadult females exhibiting long-term site fidelity. This suggests different habitat roles andspatial structuring within this social organisation. Strong and long dyadic associationsoccurred between adult females and immatures, contrarily to between males, andthe best-fitting models of the temporal patterns suggested long-lasting and temporaryassociations. The present findings unravel a complex social structure stratified by age-sexclass and influenced by female philopatry and defence polygyny, like an unimalegroup mating system, which varies from other beaked whales but is similar to somebirds, pinnipeds, or non-human primates. Cheers Filipe Alves Research Associate MARE - Marine and Environmental Sciences Centre / ARDITI Oceanic Observatory of Madeira Caminho da Penteada, Madeira Tecnopolo, 9020-105 Funchal, Portugal +351 291721216 https://mare-madeira.pt/team_member/filipe-alves/