Environmental enrichment: A GAP analysis

GAP analyses are tools used to inform us about the short-comings of a scientific area or necessities in social–economic problems. In the last 20 years, environmental enrichment as an area of scientific investigation has come of age; this can be clearly seen by the number of publications produced in this area. For example, a search on the database The Web of Science^©, using the keywords “environmental enrichment”, from 1985 to 2004 produced 744 articles. In this study we analysed these 744 articles and classified them by year into: type of environment (e.g., zoo, farm and laboratory); taxonomic classification (e.g., mammal, bird, etc.); type of enrichment (e.g., food, sensory, etc.); subject area (e.g., neurosciences and agriculture); country of publication; and gathered data on experimental design (e.g., sample sizes). Furthermore, we collected similar data on animal well-being and animal conservation for comparative purposes (keywords: “animal well-being” and “animal conservation”). The results from this study show that the number of environmental enrichment studies has been steadily increasing from a low level in the 1980s until 1999, when there was a noticeable acceleration in the number of articles published. Largely, this acceleration was a response to the growing interest in environmental enrichment by neuroscientists. The data also show a relative lack of, and recent decline in, publications in the area of agriculture. Thus, the data suggest a need for more research on enriching the lives of farm animals. Environmental enrichment publications over the 20 years of the study corresponded to 27% of all animal well-being publications in the period. One interesting comparison between enrichment and animal well-being revealed the virtual absence of research in animal well-being by neuroscientists. The detailed results of this study will help in identifying gaps in our knowledge about environmental enrichment, and how experimental designs might be improved.