Killer whale innovation: teaching animals to use their creativity upon request.

Thinking flexibly is a skill that enables animals to adapt to changing environments, which enhances survival. Killer whales, Orcinus orca, as the ocean apex predator display a number of complex cognitive abilities, especially flexible thinking or creativity when it comes to foraging. In human care, smaller dolphins and other marine mammals have been trained to think creatively while under stimulus control. The results of these previous studies have demonstrated that bottlenose dolphins, Tursiops truncatus, can create original behaviors in response to an innovative cue. We trained and tested a total of nine killer whales from two different facilities on the innovate concept, using the same methodology. The killer whales ranged in age from 5 to 29 yrs with 4 females and 5 males. The results indicate that the killer whales demonstrated high fluency, originality, some elaboration, and flexibility in their behaviors. Individual variability was observed with younger animals demonstrating more variable behaviors as compared to the older animals. Males seemed to display less complex and lower energy behaviors as compared to females, but this impression may be driven by the age or size of the animal. These results support existing evidence that killer whales are dynamic in their thinking and behavior.

Testing use of a potential cognitive enrichment device by an Indo-Pacific bottlenose dolphin (Tursiops aduncus).

Cognitive enrichment aims to provide animals with opportunities to use their cognitive skills and to promote behaviors associated with positive wellbeing. Cooperation in mammals has been recorded during various behavioral contexts such as hunting, mating, playing, and parental care. Coordinated activity, often with some level of problem-solving action included, is required during cooperation. To investigate dolphins' ability for collaborative problem-solving, an enrichment device was introduced to two adult male Indo-Pacific bottlenose dolphins (Tursiops aduncus). The device contained fish and ice and was designed to be opened by simultaneously pulling on both ends. After repeated presentation, it became apparent that only one dolphin had active interest in the device. To facilitate opportunities for problem-solving by this individual, an alternative collaborator, a human partner, was provided. Still, both dolphins had access to the device throughout the entire experiment. After the first opening, the same dolphin was highly successful in collaborating with the human in both joined (93%) and delayed (100%) partner conditions. The device provided a novel opportunity for the dolphin to use his cognitive skills. Even though only one dolphin participated actively, both dolphins showed varying degrees of interest to the device throughout the study. Both dolphins spent an average of 48% and 16% of their time, respectively, with the device, which resulted in a significant decrease in their other two most frequently observed behaviors: swimming and poolside observation. As a novel cognitive challenge, the device may be considered as a type of cognitive enrichment.

Documenting and Assessing Dolphin Calls and Ambient and Anthropogenic Noise Levels via PAM and a SPL Meter.

Song Meter SM2M marine recorders were deployed to document dolphin calls and ambient and anthropogenic noise. Recordings from Bimini were split into 2-h segments; no segment was without dolphin calls. At Dolphin Encounters, average noise levels ranged from 110 to 125 dB; the highest source level was 147.98 dB re 1 µPa at 1 m. Average ambient-noise levels documented at 4 sites in Guam were below 118 dB re 1 µPa at 1 m. These data were compared with values from a custom-built sound pressure level (SPL) meter and confirm that the SM2M recorder is a useful tool for assessing animal calls and ambient and anthropogenic noise levels.

Zoo and Aquarium Animal Welfare, Ethics, and Behavior.

This Special Issue of Animals was launched to promote the discussion of how animal welfare can be best addressed in zoos and aquariums while accommodating conservation needs, as well as how further improvements can be made in a similar vein to how medical and scientific research has advanced human health and welfare [...].

Training the Concept of Innovate in Dolphins (Tursiops truncatus) Is Both Creative and Cognitively Stimulating.

Creative or novel behaviors in bottlenose dolphins (Tursiops truncatus) can be indicators of flexible thinking and problem solving. Over 50 years ago, two rough-tooth dolphins demonstrated creative novel behaviors acquired through reinforcement training in human care. Since this novel training, a variety of species have been trained to respond to this conceptual cue. The current study assessed the creativity of 12 bottlenose dolphins (5 females, 7 males) housed at the Roatan Institute for Marine Sciences (RIMS) in Roatan, Honduras. Individual differences were found across four constructs measured for creativity: fluency, flexibility, elaboration, and originality. Variability in performance occurred across test sessions. Animals with less experience with this task performed fewer "innovative" behaviors as compared to more experienced animals. Despite errors, dolphins continued to attempt the task during test sessions, suggesting the concept of "innovate" was intrinsically rewarding and cognitively engaging. This task may be utilized across species to promote the comparative study of innovative or creative behavior as well as to promote cognitive welfare.

Characterizing dusky dolphin sounds from Argentina and New Zealand.

Dusky dolphin (Lagenorhynchus obscurus) acoustic sounds were characterized by analyzing narrowband recordings [0-16 kHz in New Zealand (NZ) and 0-24 kHz in Argentina], and sounds in broadband recordings (0-200 kHz) were compared to their counterparts in down-sampled narrowband recordings (0-16 kHz). The most robust similarity between sounds present in broadband recordings and their counterparts in the down-sampled narrowband recordings was inter-click interval (ICI); ICI was therefore primarily used to characterize click sounds in narrowband recordings. In NZ and Argentina, distribution of ICIs was a continuum, although the distribution of ICIs in NZ had a somewhat bimodal tendency. In NZ, sounds that had smaller mean ICIs were more likely to have constant ICIs, and less likely to have increasing or decreasing ICIs. Similar to some other delphinids, dusky dolphins may use single, short duration sounds that have a constant ICI and closely spaced clicks for communication. No whistles were documented at either study site. Temporally structured sequences of burst pulses (i.e., sounds with ICI < about 10 ms) also occurred at both study sites, and these sequences contained 2-14 burst pulses that appeared closely matched aurally and in spectrograms and waveforms.

The partial merger of two dolphin societies.

Interactions between mammalian social groups are generally antagonistic as individuals in groups cooperate to defend resources from non-members. Members of the family Delphinidae inhabit a three-dimensional habitat where resource defence is usually impractical. Here, we describe a long-term partial fusion of two communities of Atlantic spotted dolphins (Stenella frontalis). The northern community, studied for 30 years, immigrated 160 km to the range of the southern community, observed for 20 years. Both communities featured fission-fusion grouping patterns, strongest associations between adult males, and frequent affiliative contact between individuals. For the 5-year period following the immigration, we found members of all age classes and both sexes in mixed groups, but there was a strong bias toward finding immigrant males in mixed groups. Some association levels between males, and males and females, from different communities were as high as the highest within-community associations. Affiliative contacts indicate that these individuals were forming social relationships. The mixing of two separate social groups with new bond formation is rare in terrestrial mammal groups. Such mixing between spotted dolphin groups suggests that adaptations to respond aggressively to 'outsiders' are diminished in this species and possibly other ecologically similar dolphins.

Using social network analysis to confirm the 'gambit of the group' hypothesis for a small cetacean.

Social network analysis (SNA) can be used to explore a population's social structure and how individuals contribute to social cohesion. Quantifying relationships between individuals in a network can vary depending on the data available or the relationship of interest. Studies of readily visible species can use direct interaction measures in SNA, while studies of cryptic species usually rely on the 'gambit of the group'; individuals observed in a group are considered associates. This study compared the association and pectoral fin contact (PFC) networks of Atlantic spotted dolphins around Bimini to test the 'gambit of the group' hypothesis. The association network had nearly three times as many edges than the PFC network. Still, the two networks were correlated; individuals with a relationship in one network had a comparable relationship in the other. Many network measures were also correlated across networks, suggesting association is an acceptable substitute for physical interaction in certain cases. The current study supports the 'gambit of the group', but also highlights the importance of considering what types of relationships are used in the analysis of the social system of the focal species.

Trouble-shooting deployment and recovery options for various stationary passive acoustic monitoring devices in both shallow- and deep-water applications.

Deployment of any type of measuring device into the ocean, whether to shallow or deeper depths, is accompanied by the hope that this equipment and associated data will be recovered. The ocean is harsh on gear. Salt water corrodes. Currents, tides, surge, storms, and winds collaborate to increase the severity of the conditions that monitoring devices will endure. All ocean-related research has encountered the situations described in this paper. In collating the details of various deployment and recovery scenarios related to stationary passive acoustic monitoring use in the ocean, it is the intent of this paper to share trouble-shooting successes and failures to guide future work with this gear to monitor marine mammal, fish, and ambient (biologic and anthropogenic) sounds in the ocean-in both coastal and open waters.

A new approach to the study of relationship quality in dolphins: Framework and preliminary results.

Proximity and synchronous behaviours from surface observations have been used to measure association patterns within and between dolphin dyads. To facilitate an investigation of relationship quality in dolphins, we applied a method used for primates and ravens that examined three main components to describe relationships: value, security, and compatibility. Using pilot data from long-term research of two study populations for this preliminary assessment, these three components were extracted from PCA of eight behavioural variables with more than 80 % variance accounted for in both study groups. Only pair swim position differed between groups. Although value, security, and compatibility are abstract terms, each is based on behaviours identified as important in dolphin social life, at least for these two populations. Examining relationship quality in dolphins with a method used to illustrate dyadic differences for primates and ravens allows for a quantitative, comparative assessment of sociality across disparate taxa. Although these species are diverse in their anatomies and in their social habitats (e.g., aquatic, terrestrial, aerial), they may well share the basic societal building blocks in the factors affecting how relationships are formed. We discuss how an examination of these behavioural variables facilitates understanding relationship quality in dolphins, as well as how dolphin relationships fit into the context of social animals' society.

Is blood thicker than water? The role of kin and non-kin in non-mother-calf associations of captive bottlenose dolphins (Tursiops truncatus).

Relationships are important for social animals and kinship can play a vital role. Still, occurrence and function of kin bonds (aside from mother) in delphinid calf associations, alloparenting, or calf rearing are poorly represented in the literature. This study examined the role of kin and non-kin in non-mother-calf associations for a managed population of bottlenose dolphins. Calf associations were event sampled to determine if kin and non-kin differences existed in frequency or duration. Calves with kin present exhibited a higher average number of associates than calves without kin. Yet calves showed no conclusive association preference in frequency; though some individuals showed early signs of developing kin preferences. Duration and context of associations did not differ between kin and non-kin, suggesting they serve the same developmental purpose. However, personality, calf age, and associate age played a greater role in the formation of calf associations, supporting the notion that calves choose associates with similar traits, aiding in their development in difficult and changing environments. Though kinship is important in the formation of relationships in older dolphins, it appears that outside the mother-calf bond, there are other more influential factors, such as age, personality, and sociality in the formation of early developmental bonds.

Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (p<0.001). Prey-capture attempts most often involved capturing fish from the side of prey balls, but dolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025).

A comparison of pectoral fin contact behaviour for three distinct dolphin populations.

Tactile exchanges involving the pectoral fin have been documented in a variety of dolphin species. Several functions (e.g., social, hygienic) have been offered as possible explanations for when and why dolphins exchange pectoral fin contacts. In this study, we compared pectoral fin contact between dolphin dyads from three distinct dolphin populations: two groups of wild dolphins; Atlantic spotted dolphins (Stenella frontalis) from The Bahamas and Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan; and one group of captive bottlenose dolphins (Tursiops truncatus) residing at the Roatan Institute for Marine Sciences, Anthony's Key Resort. A number of similarities were observed between the captive and wild groups, including; rates of pectoral fin contact, which dolphin initiated contact, posture preference, and same-sex rubbing partner preference. Unlike their wild counterparts, however, dolphins in the captive study group engaged in petting and rubbing at equal rates, females were more likely to contact males, males assumed the various rubbing roles more frequently than females, and calves and juveniles were more likely to be involved in pectoral fin contact exchanges. These results suggest that some aspects of pectoral fin contact behaviour might be common to many dolphin species, whereas other aspects could be species specific, or could be the result of differing environmental and social conditions.