Abstract
The concept of “psychological well-being” was stated officially in US in 1985, for regulation of husbandry of nonhuman primates in the Amendment of Animal Welfare Act. This can be applied not to nonhuman primates but to other animals. One of the practical ways to establish the psychological well-being is the environmental enrichment. The environment enrichment aims to ensure that animals live in a captive environment which can provide opportunities to express more of their natural behavior. Recently, the improvements of husbandry with enrichment techniques are conducting in zoos and other institutions around the world. The effect of environmental operation always has to be evaluated and fed back to the next operation plan. However, the previous evaluation of the enrichment often lacked the viewpoint concerning the voluntary and sustenance of behavior. In artificial environment, there is a possibility to force animals to perform the arbitrary behavioral pattern, even if the appearance seems ideal. Therefore, this study reconfirmed the importance of the evaluation of “Selectability” and “Controllability” of the environment. Further, it was discussed that these indices are also quite effective to evaluate the enrichment for the laboratory and farm animals, which may be considerably different from the wild antecedents on behavioral pattern.
