The use of novel objects as environmental enrichment devices is a key aspect of many environmental enrichment programs, regardless of whether the animals being enriched are housed in aquaria, zoos, or laboratories. The effectiveness of novel objects as enrichment devices depends on a number of factors, many of which are based on findings from comparative psychology. For example, the literature on habituation predicts that an object that is always in an animal’s environment will be less interesting than a similar object that is available only on an intermittent basis. To test the hypothesis that type of exposure to objects affects the objects’ enriching qualities, we exposed sixteen animals from ten different species to novel objects in two different conditions. In the first condition, animals were exposed to a novel object for a total of 120 min, 60 min at a time on two separate occasions. Approximately three weeks later, the animals were once again given a total of 120 min to interact with the object that they had experienced in the first condition, but the amount of time the object was available per session was much more variable. The results demonstrate that variable presentations are more likely to maintain the enriching qualities of objects, consistent with the literature on habituation.

Observations of the spontaneous play behaviors of a group of captive bottlenose dolphins ( Tursiops truncatus ) revealed that each individual calf’s play became more complex with increasing age, suggesting that dolphin play may facilitate the ontogeny and maintenance of flexible problem solving skills. If this is so, play may have evolved to help young dolphins learn to adapt to novel situations. Novel play behaviors were more likely to be produced by dolphin calves than by adults, demonstrating that calves were the main source of innovative play behaviors in the group. Calves were also more likely to imitate novel play behaviors first produced by another dolphin, suggesting that calves contribute significantly to the spread of novel behaviors within a group. All in all, these data suggest that peers may be important catalysts for both cultural innovation and cultural transmission, and that the opportunity to interact with peers may enhance the effect play has on the emergence of flexible problem solving skills.