The 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.

For professionals caring for humans or non-human animals, many joys are to be found in working towards what an individual believes to be their calling, especially as they contribute to purposeful, meaningful work consistent with and intrinsic to their own values and beliefs. However, there can be downfalls. Empathic strain, conflict between co-workers, dissatisfaction with upper management, lack of opportunities to make positive changes, limited or no access to level and experience-appropriate professional development, and other stressors are all risks carried by organisations concerned with animal welfare. In the present study, a survey on job satisfaction and workplace stressors was completed by 311 zoo and aquarium professionals working in a range of roles from junior animal care staff to curator. Respondent profiles were created using Multiple Correspondence Analysis (MCA) and four distinct clusters were identified through Hierarchical Clustering on Principal Components (HCPC), highlighting common themes in different levels of experience and in job roles regarding stressors, satisfaction, and feelings about their work and workplaces. Overall, many zoo professionals were concerned with lacking the ability to feel empowered to do their best for animal welfare, and they described a link between the staff welfare and their perceptions of the welfare of the animals they cared for. Through identifying and understanding where organisations can better support their staff it is possible to target and reduce the number of common stressors faced by zoo professionals, leading to increased staff retention, higher job satisfaction, and an improved ability to perform at their best for animal welfare.

Scoring 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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