Meta-analytic review of the effects of enrichment on stereotypic behavior in zoo mammals
Publication Type: |
Journal Article |
Year of Publication: |
2006 |
Authors: |
Amanda Shyne |
Publication/Journal: |
Zoo Biology |
Publisher: |
A Wiley Company, Inc., Wiley Subscription Services |
Keywords: |
animals, captivity, environmental enrichment, stereotypes |
ISBN: |
1098-2361 |
Abstract:
Abstract 10.1002/zoo.20091.abs This meta-analysis reports the effect enrichment has on the occurrence of stereotypic behavior exhibited by captive zoo mammals. The analysis also identifies which types of enrichment are most effective, which groups of animals benefit the most, and which types of stereotypes are most affected by environmental enrichment. The analysis included 54 studies that yielded 63 effect size statistics. Fifty-seven of sixty-three effect sizes went in the predicted direction (90%), with the animals participating in less stereotypic behavior during the enrichment condition than in the baseline condition. The mean effect size (correlation coefficient r) was 0.46. The combined P-value using both fixed and random effects methods was reveled to be <0.0000001. A file drawer N-value was calculated to identify the number of unretrieved studies (with a combined effect size of zero) that would be needed to nullify the results of this analysis. The file drawer N-value was 1,726, suggesting that it is highly unlikely that the significant results reported in this analysis are nullified by studies that remain in file drawers. Based on these results it was concluded that enrichment substantially reduces the frequency of stereotypic behavior exhibited by mammals living in zoo environments. Zoo Biol 0:1–21, 2006. © 2006 Wiley-Liss, Inc.