Chamove, A. S., Moodie, E. M. 1990. Objective criteria of enrichment. Congress of the International Primatological Society, NGY19.

39 cotton-top tamarins living in four families were observed following stimulating husbandry procedures [capture, birds passing overhead]. Arousal led to an improvement in behaviour (i.e., decrease in activity and an increase in affiliation) during the remainder of the day.