ETHOLOGICAL STUDY ON A GROUP OF MUSTACHED MONKEYS (Cercopithecus cephus): EFFECTS OF ENVIRONMENTAL ENRICHMENT ON INDIVIDUAL WELFARE

In this study, four male moustached monkeys (Cercopithecus cephus) housed at the Safari Park in Pombia were observed. The objective of the research was to evaluate any behavioral and physiological responses of the individuals following the introduction of three types of environmental enrichments: food-based, object-based, and olfactory. Data collection was carried out in 2025 using video recordings conducted three weekdays per week, across three periods of six weeks each, in order to evaluate a potential seasonal effect, alternating control weeks with enrichment weeks. The duration of behaviors was collected using continuous recording and focal animal sampling through the Boris software. Concurrently, at the end of each day, three fecal samples were collected and analyzed using ELISA testing to determine the concentration of fecal cortisol metabolites. The results of the behavioral observations showed a clear prevalence of active behaviors, which occupied approximately 80% of the individuals' total activity time. Furthermore, a potential seasonal effect emerged, with the summer period appearing to offer more favorable environmental conditions for the well-being of the individuals housed at the zoological facility. The introduction of enrichments significantly influenced the behavior of the observed subjects. In the absence of enrichments, higher levels of vigilance and high-activity behaviors were recorded, suggesting a greater search for environmental stimuli. Conversely, in the presence of enrichments, the individuals showed a significant increase in foraging and exploratory behaviors, consistent with those observed in the wild in moustached monkeys and indicative of an improvement in welfare conditions. Among the different types proposed, the individuals showed greater interest in food-based enrichments. Fecal cortisol metabolite analysis did not show consistent patterns associated with the presence of enrichments, instead highlighting a marked variability among the samples. Overall, the results emphasize the role of environmental enrichments in promoting species-specific behaviors and underscore the importance of further ethological studies to deepen the understanding of the species and improve the management and well-being of individuals in controlled environments.