Spontaneous activities of captive performing bottlenose dolphins (Tursiops truncatus)

Abstract

Despite the number of dolphins that have been kept in dolphinaria, and the many behavioural studies that have been conducted on captive dolphins, few have focused on their welfare. Some behaviours have been described in detail, but insufficient attention has been paid to the diurnal variations in their occurrence. Behavioural observations were conducted upon two groups (two and six individuals each) of captive bottlenose dolphins (Tursiops truncatus) over a period of six weeks. Behavioural descriptions were produced and the amount of time the animals spent engaged in different behaviours was sampled. General trends of both groups and differences in patterns of variation throughout the day were also analysed. The use of area by the dolphins and their degrees of association were recorded. Considerable individual variation and differences between the two groups were observed. In comparing the behaviour of different dolphins and in considering their welfare it is necessary to take into account their marked degree of individuality. The observations have shown that behavioural data such as variability of behaviour patterns, spontaneous variations in the daily activities and frequency of playing and exploration may constitute good welfare indicators. It is argued that social diversity, appropriate physical characteristics of the pools, existence of play objects in the pools, easy access to visual contact with people, and frequent interactions with the trainers throughout the day at unscheduled times may be important ways of improving environmental stimulation.