Can colored object enrichment reduce the escape behavior of captive freshwater turtles?

The effect of environmental enrichment on the behavior and welfare in captivity of reptiles and of freshwater turtles in particular, which are popular aquarium and pet species, is very little studied compared to other taxa. We carried out a small scale case-study on the effect of colored object enrichment, with and without fish scent, on the behavior of a group of 15 cooters (Pseudemys sp.) and sliders (Trachemys scripta ssp.) on display at a public aquarium. The new enrichment aimed to reduce the escape behavior (interaction with transparent boundaries) and increase exploration and random swimming. We used simultaneous recording of behavior at whole group level and for focal individually-marked turtles. The escape behavior decreased on days with new enrichment before feeding at whole group level and for the focal turtles overall, in spite of the relatively low interest in the colored objects. Fish-scented objects attracted significantly more interest. Random swimming, enrichment focus, aggression and submission increased significantly, and basking decreased significantly at whole group level before feeding, with smaller differences after feeding. There were large differences between individual turtles with respect to activity budgets and changes in behavior on days with new enrichment, with both increases and decreases seen in escape behavior, aggression, and levels of activity. Our outcomes suggested that introducing new colored objects with food scent may be beneficial for reducing escape behavior in captive freshwater turtles. However, careful monitoring of effects at individual level and much larger scale investigations, including postenrichment periods, are needed.