Happiness is positive welfare in brown capuchins (Sapajus apella)

Welfare questionnaires, which allow people who are familiar with individual animals to rate the welfare of the animals, are an underutilised tool. We designed a 12-item welfare questionnaire and tested its reliability and associations with subjective well-being (SWB), locomotor stereotypy, and personality traits. The welfare questionnaire included questions relating to physical health, stress and coping, satisfaction with social relationships, psychological stimulation, and the display of positive and negative welfare indicators. We collected ratings of 66 brown capuchins (Sapajus apella) living in three facilities. Each capuchin was rated on the welfare questionnaire by an average of 2.8 raters. The interrater reliability of the welfare questionnaire items ranged from ICC(3,k) 0.51 to 0.86. A principal components analysis indicated that the 12 welfare items loaded onto one component. We repeated this process with the welfare and subjective well-being items and found all the items were defined by a single component (welfareSWB). We then conducted three sets of analyses, one predicting the welfare component, one predicting the SWB component, and predicting the welfareSWB component. The independent variables were frequency of locomotor stereotypy, personality, age, and sex; facility was included as a random effect. In models including stereotypy, age, and sex we found frequency of stereotypy to be significantly associated with all three predicted components (p < 0.01). After controlling for stereotypy (b = −0.25, p = 0.17), age (b = −0.54, p = 0.01), and sex (b = −0.32, p = 0.07), the personality traits of Sociability (b = 1.02, p < 0.001), Assertiveness, (b = 0.63, p < 0.001), and Attentiveness (b = 0.54, p = 0.01) were associated with higher scores on the joint welfareSWB component; Neuroticism was negatively associated (b = −0.60, p = 0.01). Our results suggest that welfare questionnaires may be a useful, reliable, and valid tool for primate welfare assessment.