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Person
de Noronha Gamito Afonso dos Santos, Manuel Eduardo
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- Feeding behaviour of the bottlenose dolphin, Tursiops truncatus ( Montagu, 1821 ) in the Sado estuary, Portugal, and a review of its prey speciesPublication . Santos, Manuel Eduardo dos; Coniglione, Chiara; Louro, SóniaComportamento alimentar do golfinho-bico-de-garrafa, Tursiops truncatus ( Montagu, 1821 ) no estuário de Sado, Portugal e uma revisão de suas espécies de presas. O objetivo desse artigo é apresentar a informação disponível acerca do comportamento alimentar e da dieta dos golfinhos-bico-de-garrafa residentes no estuário de Sado, em Portugal. Os golfinhos-bico-de-garrafa são predadores oportunistas, com uma dieta diversificada que inclui crustáceos, cefalópodes e peixes pelágicos e bentônicos, de acordo com a disponibilidade e abundância. A observação direta dos comportamentos alimentares, apoiada por registros fotográficos e videofotográficos, permitiu a identificação de algumas das espécies de presas do golfinho desta região, nomeadamente a enguia-europeia, taínhas, o choco-comum e o polvo. Uma lista de espécies de presas mais comuns dos golfinhos-bico-de-garrafas em diversas regiões foi comparada com as espécies de peixes e cefalópodes que ocorrem no estuário do Sado. Esta comparação levou à uma elaboração de uma lista adicional de espécies que provavelmente também são presas dos golfinhos na região. A observação de comportamentos alimentares foi mais frequente nas partes mais rasas da área de estudo, onde deverá ser mais fácil encontrar e capturar presas.
- Brays and bits: Information theory applied to acoustic communication sequences of bottlenose dolphinsPublication . Luís, Ana Rita; Alves, Inês Sofia Carvalho Alves; Sobreira, Filipa Veiga; Couchinho, Miguel Nogueira; Santos, Manuel Eduardo dosAcoustic call sequences are important components of vocal repertoires for many animal species. Bottlenose dolphins (Tursiops truncatus) produce a wide variety of vocalizations, in different behavioural contexts, including some conspicuous vocal sequences – the ‘bray series’. The occurrence of brays is still insufficiently documented, contextually and geographically, and the specific functions of these multi-unit emissions are yet to be understood. Here, acoustic emissions produced by bottlenose dolphins in the Sado estuary, Portugal, were used to provide a structural characterization of the discrete elements that compose the bray series. Information theory techniques were applied to analyse bray sequences and explore the complexity of these calls. Log-frequency analysis, based on bout criterion interval, confirmed the bout structure of the bray series. A first-order Markov model revealed a distinct pattern of emission for the bray series’ elements, with uneven transitions between elements. The order in these sequential emissions was not random and consecutive decreases in higher order entropy values support the notion of a well-defined structure in the bray series. The key features of animal signal sequences here portrayed suggest the presence of relevant information content and highlight the complexity of the bottlenose dolphin’s acoustic repertoire.
- Whistle stability and variation in captive bottlenose dolphins (Tursiops truncatus) recorded in isolation and social contextsPublication . Lopes, Patrícia Alexandra Rachinas; Luís, Ana Rita; Borges, Ana Sofia; Neto, Márcia P.; Santos, Manuel Eduardo dosCommon bottlenose dolphins (Tursiops trunca-tus) produce a range of underwater vocalizations, both pulsed (echolocation clicks and burst-pulses) and nonpulsed (whistles). Whistles may be emit-ted in stereotyped (signature) or variant patterns, and their production might be affected by sex, age, environmental, and social contexts. This study examined, non-intrusively, the whistle emissions of six captive bottlenose dolphins at Zoomarine in Algarve, Portugal, in two separate time sets and three different contexts: two of the animals in isolation in 2008, and all six in 2012, both seg-regated from their group and in social context. From a total of 1,681 whistles, 1,249 were ana-lyzed from 32 samples in different contexts: seven samples in isolation in 2008, 18 in segregation in 2012, and seven in social context. Through visual inspection of spectrograms, whistles were classi-fied into 12 different contour categories. Only one category was found in both time sets and could be considered a signature whistle by SIGID criteria (Janik et al., 2013). This contour was associated with the same animal in 2008 and 2012. Whistle emission rates were 7.8 times higher in isolation as compared with social context, and significant differences were also found in the end and maxi-mum frequencies as well as number of inflections and loops. Multiloop whistles were more common in isolation than in social contexts. The variant (nonstereotyped) contours dominated the whistle production in segregated contexts (but not by iso-lated animals) as well as in social contexts. This study highlights the importance of examining the nonstereotyped portion of the bottlenose dolphin’s whistle repertoire in different contexts as signa-ture whistle production may not be a constant or universal phenomenon.
- Social structure of the declining resident community of common bottlenose dolphins in the Sado Estuary, PortugalPublication . Augusto, Joana F.; Lopes, Patrícia Alexandra Rachinas; Santos, Manuel Eduardo dosThe resident population of common bottlenose dolphins (Tursiops truncatus) in the Sado Estuary, Portugal, has been declining at least during the past three decades. A complete photographic census produced a current count of 24 animals—19 adults, three subadults and two calves. It appears to be phylopatric and essentially closed, but given the likely importance that exchanges with neighbouring coastal groups may play, even if rare, the most adequate term to define this dolphin should be community and not population. Large groups with all age-classes are common in the community, possibly as a calf and subadult protection strategy, and this may be related to the fact that these age-classes have had high mortality rates in the last decade. Maternity of two calves was determined, and we found that the two mothers adopted different parenting strategies. While one mother spent more time alone with her calf, the other mother spent more time with her calf in larger groups. The average coefficient of association for this community is 0.45, quite high for this species. Associations and typical group size are similar between all individuals, with no patterning according to age-class or sex, which constitutes an atypical trait for dolphin societies. There are also no clear divisions in this community according to cluster analysis. Associations are preferred and long term, lasting approximately 34 days and fitting a pattern of casual acquaintances, where individuals associate for a period of time, disassociate and may reassociate after that. This reflects the fission– fusion character of the community, but in a more stable manner. We think this is caused by a combination of demographic characteristics and a stable and productive environment, which led to a decrease in competition between individuals.
- Effects of a dolphin interaction program on children with autism spectrum disorders – an exploratory researchPublication . Salgueiro, Emílio Eduardo Guerra; Nunes, Laura; Barros, Alexandra; Maroco, João; Salgueiro, Ana Isabel; Santos, Manuel Eduardo dosBackground: Interaction programs involving dolphins and patients with various pathologies or developmental disorders (e.g., cerebral palsy, intellectual impairment, autism, atopic dermatitis, post-traumatic stress disorder, depression) have stimulated interest in their beneficial effects and therapeutic potential. However, the true effects observed in different clinical and psycho-educational setups are still controversial. Results: An evaluation protocol consisting of the Childhood Autism Rating Scale (CARS), Psychoeducational Profile-Revised (PEP-R), Autism Treatment Evaluation Checklist (ATEC), Theory of Mind Tasks (ToM Tasks) and a custom-made Interaction Evaluation Grid (IEG) to evaluate behavioural complexity during in-pool interactions was applied to 10 children diagnosed with Autism Spectrum Disorders. The ATEC, ToM Tasks and CARS results show no benefits of the dolphin interaction program. Interestingly, the PEP-R suggests some statistically significant effects on ‘Overall development score’, as well as on their ‘Fine motor development’, ‘Cognitive performance’ and ‘Cognitive verbal development’. Also, a significant evolution in behavioural complexity was shown by the IEG. Conclusions: This study does not support significant developmental progress resulting from the dolphin
- Monitoring underwater explosions in the habitat of resident bottlenose dolphinsPublication . Santos, Manuel Eduardo dos; Couchinho, Miguel Nogueira; Luís, Ana Rita; Gonçalves, Emanuel JoãoMaintenance work on the harbor of Setu´bal, in Portugal, required the removal of a 14-m deep rocky outcrop at the ship maneuver area, using about 35 kg of Gelamonite, a nitroglycerin-based highexplosive. This important harbor is located in the Sado estuary, a biologically rich environment and an important feeding area for a resident community of bottlenose dolphins. Using different safe range calculation models, a mitigation and monitoring plan was developed that minimized the risks of these underwater explosions for the dolphins. At our monitoring station, at 2 km from the demolition site, acoustic pressure levels in excess of 170 dB re 1 lPa (root-mean-square) were measured. Samples of dead fish collected at the site were indicative of shock trauma from the blasts.
- Satellite tracking of sea turtles released after prolonged captivity periodsPublication . Mestre, Frederico; Bragança, Marco P.; Nunes, Antonieta; Santos, Manuel Eduardo dosRehabilitation is an important part of sea turtle conservation, and post-release tracking of the animals is both a way of obtaining information on their movements and behaviour and, at least temporarily, monitoring the success of the rehabilitation process. Two green turtles, Chelonia mydas, and one loggerhead turtle, Caretta caretta, were rehabilitated after long periods in captivity, and their movements followed by satellite tracking after their release near the south of Portugal. Location data were obtained for an average of 688 days after release. All three animals showed a directional movement and the last observed locations coincided with known feeding areas for both species, near the coasts of Mauritania and the state of Ceará, Brazil, for the green turtles, and near Cuba for the loggerhead. Bathymetry, surface currents, wind, sea surface temperature, chlorophyll-a concentration and geomagnetic field were analysed as spatial and environmental variables potentially affecting movement. Only bathymetry, sea surface temperature and geomagnetic variables showed significant association with the path choice. This project supports the notion that sea turtles have the ability to survive in the wild after long periods in captivity and to return to the species' known feeding areas, justifying the effort in their rehabilitation and post-release tracking.
- Correction: D-Track—A semi-automatic 3D video-tracking technique to analyse movements and routines of aquatic animals with application to captive dolphinsPublication . Rachinas-Lopes, Patrícia; Ribeiro, Ricardo; Santos, Manuel Eduardo dos; Costa, Rui M.There is an error in the XML that is causing the third author’s name, Rui M. Costa, to be indexed incorrectly. The name should be indexed as Costa, Rui M. The correct citation is: Rachinas-Lopes P, Ribeiro R, dos Santos ME, Costa RM (2018) D-Track—A semi-automatic 3D video-tracking technique to analyse movements and routines of aquatic animals with application to captive dolphins. PLoS ONE 13(8): e0201614. https://doi.org/10.1371/journal.pone. 0201614.
- Cetaceans of the cape verde archipelagoPublication . Reiner, Francisco; Santos, Manuel Eduardo dos; Wenzel, Frederick W.; Whale, Alliedinexistente
- D-Track—A semi-automatic 3D video-tracking technique to analyse movements and routines of aquatic animals with application to captive dolphinsPublication . Lopes, Patrícia Rachinas; Ribeiro, Ricardo; Santos, Manuel Eduardo dos; Costa, Rui MiguelScoring and tracking animal movements manually is a time consuming and subjective process, susceptible to errors due to fatigue. Automated and semi-automated video-based tracking methods have been developed to overcome the errors and biases of manual analyses. In this manuscript we present D-Track, an open-source semi-automatic tracking system able to quantify the 3D trajectories of dolphins, non-invasively, in the water. This software produces a three-dimensional reconstruction of the pool and tracks the animal at different depths, using standard cameras. D-Track allows the determination of spatial preferences of the animals, their speed and its variations, and the identification of behavioural routines. We tested the system with two captive dolphins during different periods of the day. Both animals spent around 85% of the time at the surface of the Deep Area of their pool (5-meters depth). Both dolphins showed a stable average speed throughout 31 sessions, with slow speeds predominant (maximum 1.7 ms-1). Circular swimming was highly variable, with significant differences in the size and duration of the "circles", between animals, within-animals and across sessions. The D-Track system is a novel tool to study the behaviour of aquatic animals, and it represents a convenient and inexpensive solution for laboratories and marine parks to monitor the preferences and routines of their animals.
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