Abstract

Environmental and behavioral enrichment techniques used with captive wild animals have become important for improving the quality of life and the reproductive performance of several species. The evaluation of the techniques should be done combining behavioral and hormonal parameters. The best way to measure hormones for this purpose is to use non-invasive techniques such as fecal hormone analysis. The aim of this work was to apply enrichment techniques to treat an acyclic captive female chimpanzee (Pan troglodytes) kept at the Sao Paulo Zoo, and to monitor the effects through the analysis of behavioral, hormonal, and physical (perineal tumescence) aspects. The first phase lasted 60 days and included 80 hours of behavioral observations through ethograms obtained by the focal sampling method and simultaneously collecting daily fecal samples in order to measure the levels of cortisol and estradiol. The perineal tumescence was subjectively scored. The aim of this phase was to characterize the current hormonal, behavioral, and perineal patterns before the introduction of the enrichment techniques. The second phase was characterized by the introduction of the enrichment techniques followed by another 80 hours of the same analysis of behavioral, hormonal, and perineal aspects previously described. The second phase also lasted 60 days. The results of the first phase showed a clear behavioral dysfunction with a high frequency of stereotypic (abnormal) behaviors associated with high levels of cortisol and low levels of estradiol followed by the absence of the ovarian cycle. In the second phase, the results showed a marked reduction in the frequency of stereotypic behaviors after the introduction of the enrichment, followed by the resumption of the ovarian cyclic activity demonstrated by the perineal tumescence patterns and fecal estradiol profile. In this phase, the fecal levels of cortisol presented an initial rise followed by a marked reduction to significant and sustained lower levels. In conclusion, our results strongly suggested that the enrichment techniques were efficient to treat the non-cyclic condition of this female chimpanzee, promoting a reduction of the stress level and resumption of the ovarian cyclicity.