Effect of Visitor Number on the Behavior and Cortisol Metabolites Concentrations of Sambar Deer (Cervus unicolor) in Captivity

Abstract

The effect of the visitor on animal behavior in captivity has been widely reported. However, whether this visitor-effect also influences stress for captive animals is still limited and absent for captive Sambar deer (Cervus unicolor). Therefore, the objective of this study was to examine the effect of visitor numbers on the behavior and cortisol metabolites concentrations in captive Sambar deer. This study used 8 Sambar deer living in the Taman Rusa Lamtanjong, Aceh Besar. In total, 640 hours of behavior data were collected using focal animal sampling during two-month observations. During behavioral observations, the number of visitors to the Sambar deer cage was recorded and 35 fecal samples were collected. Fecal samples were then extracted and measured the cortisol metabolite concentration using a specific antibody, 11ßhydroxy-etiocholanolone, through an enzyme-linked immunosorbent assay (ELISA) method. Data were analyzed using a paired sample t-test and Spearman Rank correlation. The concentrations of cortisol metabolites were significantly higher when the presence of human visitors (301.06±37.21 ng/g feces) compared to the absence of human visitors (202.15±88.07 ng/g feces) in the cage (p<0.01). In addition, the number of visitors was significantly correlated with the increase of cortisol metabolites concentrations ( rs =0.510, p <0.01). Moreover, the presence of human visitors influences the animal behaviors particularly decrease the feeding activity (rs= -0.232, p<0.05), and increase the foraging (rs=0.263, p<0.05) and grooming (rs=0.355, p<0.01) activities. In conclusion, the number of visitors affected the increases of cortisol metabolites concentrations and influences some of the animal behaviors.