Zoos and aquariums, which are visited by over 700 million people each year, can play a vital role in exposing and sensitising visitors about the importance of environmental conservation and encourage them to engage in environmentally responsible behaviours after their visit. To attract visitors, zoos and aquariums offer a range of experiences that focus on the viewing of live animals. These may include animal presentations, personal interactions between staff and visitors, opportunities to physically interact with the animals and, most commonly, the use of interpretive signage. Most zoo and aquarium experiences are aimed at increasing visitors' awareness of, interest in and concern for environmental issues. To improve the design of visitor experiences, research is needed to evaluate the impact of a visit on visitor environmental learning outcomes, which are a major part of the zoo and aquarium raison