The Effects of Multileveled Enrichment on Behaviors Indicating Distress and Well-Being in Captive Squirrel Monkeys (Saimiri sciureus)
Environmental enrichment has been known to enhance well-being in primates and other animals, although the specific link between the two has yet to be determined. One of the biggest difficulties of comparing enrichment studies is that there are no standardized indicators of enrichment level, as well as no widely agreed upon indicators of well-being or distress. The difficulties and potential problems in subjectively defining terms like "well-being" and "distress" in nonhuman primates make research consistency tough to establish. This study tested the effect of five levels of environmental enrichment on behaviors that indicate distress and well-being in squirrel monkeys. The multi-level design was implemented in order to identify whether or not there was a point at which the enrichment no longer had any additional effect on levels of well-being and distress, also known as a threshold effect. Behavioral changes were examined within the design so that subjectsnull progress could be measured on and compared to each of the other levels, enhancing the total reliability of the study. As enrichment levels increased, I expected that stereotypic behaviors would be less frequent, behavioral diversity would be more prevalent, and tolerance of stress would be higher. My data suggest that stereotypic behaviors decrease at a specific threshold as enrichment is added. Other indicators such as tolerance of stress appeared at a much higher threshold along with enrichment change. This suggests that different measures of well-being and distress may be more or less sensitive to changes in environmental complexity, and that future enrichment studies should consider including detailed descriptions of baseline conditions in order to improve validation and interpretation of behavioral fluctuations.
Franklin and Marshall College Archives, Undergraduate Honors Thesis 2007
- F&M Theses Collection