Abnormal behaviours may develop in animals housed in human-made environments, if they do not allow them to carry out their natural behaviours such as swimming, climbing, stalking, and predation (Pitsko, 2003).  This is even more evident in tigers due to spatial constraints and negative public reaction.  They have large home ranges in the wild, and natural predatory hunting behaviours are difficult to provide for in captivity(Pitsko).  According to Pitsko’s study, tigers kept in more natural and complex enclosures performed less stereotypic pacing (unnatural behaviours), and more exploratory (natural behaviours) than those housed in less natural enclosures.

Environmental enrichment is the process in which animals’ captive environments are manipulated to provide various items and spaces that will stimulate their psychological and physiological well being (Sheperdson et al., 1998).  Normal behaviours can be defined as “the exhibition of a phenotypic trait within the environmental context for which primary selective forces have shaped it, the outcome of which being maximal, inclusive fitness” (Eisenberg, 1981).  In captivity, these “normal” behaviours are often replaced by abnormal, or “stereotypic” behaviours such as pacing (Pitsko).

Zoochosis refers to the same psychological effects from confinement that occurs in people.  Tigers unable to freely move, denied a rich social life, their every need and instinct thwarted, and in possession of complex minds, zoo animals suffer from various psychological problems, from “stereotypic” behaviour that includes pacing, head-bobbing, rocking, walking in circles, compulsive licking, bar biting, and even self-mutiliation (Best, 1999).

To hopefully prevent many of these abnormal behaviours, zoo/tiger owners have many ways to keep their tigers enriched.  The hope is that by keeping the animals busy through enrichment, the highest standards of animal welfare, where animals are healthy, active and exhibit a wide diversity of behaviours are met.  Environmental enrichment improves or enhances zoo environments for animals, stimulating them to investigate and interact with their surroundings (Calstead, 2008).  Calstead enriches animal environments by making changes to structures in their enclosures, presenting novel objects and smells for them to investigate and explore, and by changing how we present food to them.  She believes doing all these things alleviates boredom by giving animals more choice of activity.  It encourages them to forage, hunt and handle their food in ways that are natural to them in the wild (Calstead).  For these reasons, she believes enrichment improves animal welfare.  Not only does it enhance the public’s experience of animals, but enrichment can help reduce stress and promote successful reproduction.