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The conservation of marine megafauna presents numerous difficulties owing to their high mobility over difficult‐to‐access oceanic areas that impairs the collection of basic, but essential, biological information.The Bryde's whale (Balaenoptera edeni) is one of the most elusive species of baleen whales, and although it is known to be a seasonal visitor to several archipelagos in Macaronesia (the Azores, Madeira, and Canaries), there are no studies regarding its occurrence or geographical connectivity in this area of the Atlantic.A 14‐year photographic database was used to determine short‐term (intra‐seasonal) and long‐term (inter‐annual) Bryde's whale site fidelity and to estimate individual residency times in Madeira, whereas photographic catalogues from Madeira and the Canaries were compared in order to assess large‐scale movements (i.e. on the scale of hundreds of kilometres).In Madeira, 59 individuals were identified, 27 (45.8%) of which were recaptured. Of these, 10 individuals (37.0%) presented short‐term site fidelity and 17 individuals (63.0%) presented long‐term site fidelity, with a maximum recapture interval of 12 years. Lagged identification rates showed that five individuals (SE = 2) remained in the area for 32 days (SE = 108 days) before leaving and not returning during the same year. Seven individuals were seen both in Madeira and the Canaries (catalogue comprising 51 individuals), three of which were identified multiple times in both archipelagos, with a minimum of 43 days between consecutive sightings.This information combined with the fact that this species is commonly sighted accompanied by calves and feeding in both archipelagos highlights the ecological importance of this area for Bryde's whales. This should be taken into consideration by policymakers when implementing conservation measures, where coordination of effort among countries is needed. This study also reinforces the value of using data from platforms of opportunity and of making photographic data open access. [ABSTRACT FROM AUTHOR]

Cetaceans are considered ecosystem engineers and useful bioindicators of the health of marine environments. The Eastern North Atlantic is an area of great geographical and oceanographic complexity that favours ecosystem richness and, consequently, cetacean occurrence. Although this occurrence has led to relevant scientific research on this taxon, information on the composition of this research has not been assessed.We aimed to describe and quantify the evolution of research on cetaceans in the Eastern North Atlantic, highlighting the main focal areas and trends.We considered 380 peer‐reviewed publications between 1900 and 2018. For each paper, we collected publication year, research topics and regions, and species studied. We assessed differences among regions with distinct socio‐economic landscapes, and between coastal and oceanic habitats. To evaluate the changes in scientific production over time, we fitted a General Additive Model to the time series of numbers of papers.Although research in this region has been increasing, the results show relatively little research output in North African and coastal regions within the study area. Moreover, except for four studies, research was restricted to a few miles around the coast of the main islands, leaving offshore regions less well surveyed. There was little research on genetics, acoustics, and behaviour. Most papers were focused on the Azores and Canary Islands, and mostly involved Tursiops truncatus, Delphinus delphis, and Physeter macrocephalus. Species considered Endangered or Near Threatened were the subjects of only 10% of the studies.We suggest a greater research focus on beaked whales (Ziphiidae) in Macaronesia, as well as collaborative efforts between research teams in the region, by sharing data sets, and aiming to produce long‐term research. Moreover, a Delphi method approach, based on questionnaires answered by experts, could be attempted to identify priority research for cetaceans in these areas. [ABSTRACT FROM AUTHOR]

Wide-ranging connectivity patterns of common bottlenose dolphins (Tursiops truncatus) are generally poorly known worldwide and more so within the oceanic archipelagos of Macaronesia in the North East (NE) Atlantic. This study aimed to identify longrange movements between the archipelagos of Macaronesia that lie between 500 and 1,500 km apart, and between Madeira archipelago and the Portuguese continental shelf, through the compilation and comparison of bottlenose dolphin's photo-identification catalogues from different regions: one from Madeira (nD363 individuals), two from different areas in the Azores (n D 495 and 176), and four from different islands of the Canary Islands (nD182, 110, 142 and 281), summing up 1791 photographs. An additional comparison was made between the Madeira catalogue and one catalogue from Sagres, on the southwest tip of the Iberian Peninsula (nD359). Results showed 26 individual matches, mostly between Madeira and the Canary Islands (nD23), and between Azores and Madeira (n D 3). No matches were found between the Canary Islands and the Azores, nor between Madeira and Sagres. There were no individuals identified in all three archipelagos. The minimum time recorded between sightings in two different archipelagos (≈ 460 km apart) was 62 days. Association patterns revealed that the individuals moving between archipelagos were connected to resident, migrant and transient individuals in Madeira. The higher number of individuals that were re-sighted between Madeira and the Canary Islands can be explained by the relative proximity of these two archipelagos. This study shows the first inter-archipelago movements of bottlenose dolphins in the Macaronesia region, emphasizing the high mobility of this species and supporting the high gene flow described for oceanic dolphins inhabiting the North Atlantic. The dynamics of these long-range movements strongly denotes the need to review marine protected areas established for this species in each archipelago, calling for joint resolutions from three autonomous regions belonging to two EU countries. [ABSTRACT FROM AUTHOR]