Point for Enrichment, Point for Welfare-Testing Use of a Laser Pointer with Arapaima gigas.

The arapaima (Arapaima gigas) is one of the largest freshwater fish species, known to exceed 3 m in total length. It is listed as Data Deficient by the IUCN. A. gigas is native to the Amazon River basin where they are an important food source. Arapaimas are also farmed for meat and for live specimens in various South American and Asian countries. Despite decades of keeping the species in public aquariums, little is known of its behaviour and cognitive abilities. This pilot study provides baseline data on using a green laser pointer as environmental enrichment for this species under human care. The data collection included 18 observations before the use of the laser pointer (baseline) and 18 observations during the use of the laser pointer (test). Ten behaviours were monitored, investigating physical contact, activity pattern and habitat use by the fish. During the test, the fish significantly increased their presence in the tank, their level of activity and their use of the habitat. This pilot study provides valuable baseline data for further investigations demonstrating the value of a laser pointer as environmental enrichment for A. gigas under human care.

Testing use of the first multi-partner cognitive enrichment devices by a group of male bottlenose dolphins.

Alliance formation plays a crucial part in male dolphins' lives. These partnerships may last for decades or even for a lifetime; thus, partner choice and the maintenance of these relationships are both considered key components of alliance formation. In our previous investigations, pairs of adult male dolphins showed a high success rate in cooperative manipulation of a cognitive enrichment device. Here, we introduced two novel cognitive enrichment devices to the group of five dolphins, facilitating simultaneous actions for not only pairs, but for three or even four dolphins. The devices were made of PVC tubes, fittings and caps equipped with rope handles, creating a three-way (T-shape) and a four-way (TT-shape) device. The devices were filled with fish and ice and were designed to be opened by simultaneous pull of the handles. Both devices were tested in 12 trials (each lasted for 15 min), separately. Only one of the caps could be opened, the others were affixed with the position of the openable cap counter-balanced over the trials. Although the dolphins received no training regarding the manipulation of the devices, they were successful in cooperatively opening the three-way devices in 10/12 of trials (70% by two and 30% by three dolphins) and the four-way devices also in 10/12 trials (50% by two, 40% by three and 10% by four dolphins). The dolphins interacted with the devices during the entire testing time, and this was mostly spent in cooperative play (77% and 56% of the test duration with the three-way and four-way device, respectively). The majority of the cooperative play was observed between one particular pair of dolphins that was temporarily associated with a third or sometimes even with a fourth dolphin. These findings demonstrate the first successful use of multi-partner cooperative enrichment devices, providing information on the social organization of a male dolphin group.

Group size, partner choice and collaborative actions in male Indo-Pacific bottlenose dolphins (Tursiops aduncus).

Due to the diversity of the phenomenon, dolphin cooperation has attracted considerable research interest in both wild populations and those under human care. Dolphins cooperate in various contexts, including group hunting, alloparental care, social learning, social play and alliance formation for securing mates. This investigation focused on the effect of group size and partner choice in a cooperative task using systematic group testing. A cooperative enrichment device was made of a PVC tube containing fish and ice that was temporarily sealed with two PVC caps with rope handles attached. The device was designed to be operated by pairs of dolphins, opened by simultaneous pull of its two handles. The analysis focused on two behaviours, cooperative opening and cooperative play with the device. Testing focused on an adult male dolphin group including four to six individuals and using a single or two devices. Altogether five group testing arrangements and a pairwise testing phase were conducted. Out of the six dolphins, five showed active involvement. All ten possible pairs of the five active dolphins were successful in opening and playing with the device cooperatively. Cooperation increased with group size, but the social networks showed no significant differences among group arrangements. However, the cooperative pairs showed a significant difference in success rate during pairwise vs group testing, while demonstrating a strong partner preference. This study provides the first evidence for partner choice with regards to cooperation in male dolphins.

Cognitive enrichment device provides evidence for intersexual differences in collaborative actions in Indo-Pacific bottlenose dolphins (Tursiops aduncus).

Social living, long lifespan and advanced cognitive skills provided favourable conditions for the development of pro-social behaviours and cooperative activities in cetacean. Dolphins have been observed to collaborate for various purposes, finding food, finding mates or raising and teaching younger individuals. This study investigated the potential impact of demographic factors (sex and age), social factors (relatedness and group size), and individual experience in a cooperative problem solving task. A cognitive enrichment device was tested with 22 dolphins in 11 group settings. The device consisted of a tube, containing ice and fish, sealed by two caps with rope handles and designed to be operated by pairs of dolphins. The investigation focused on the differences in trial outcome (success rate of cooperative opening of the device) and on cooperative play (dolphin pairs engaging in synchronous swim with the device). From the five potential factors, sex showed the highest impact. Cooperative openings were more than four times more frequent in males than in females (75% vs 17%, respectively), and cooperative play was exclusively displayed by adult males. Given the strong correlation between cooperative opening and cooperative play, we argue the two behaviours can be regarded as parts of a cooperative action chain. This study provides the first evidence for intersexual differences in collaborative actions in dolphins under systematic testing conditions.

Lateralization in accuracy, reaction time and behavioral processes in a visual discrimination task in an Indo-Pacific bottlenose dolphin (Tursiops aduncus).

Perceptual and behavioral asymmetry has been observed in a wide range of vertebrate and invertebrate species with its origin estimated to go back over 500 million years. Previously, hemispheric lateralization in marine mammals has been recorded during foraging, parental care, preferred swimming direction as well as when solving cognitive challenges. Visual laterality has been demonstrated in preferred eye use and performance accuracy. A female Indo-Pacific bottlenose dolphin was trained to associate eight pairs of non-identical visual stimuli. Her performance was tested and compared under binocular and monocular conditions. No significant difference was found in accuracy, while a clear left eye advantage was demonstrated in reaction time. In addition, behavioral asymmetry was observed in movement pattern preference during the stimulus discrimination.