Male reunion displays in tufted capuchin monkeys (Cebus apella)

When males in captive tufted capuchin monkey (Cebus apella) groups separate and come together within their group, they have been observed to embrace and vocalize upon reunion. This display has not been observed in any other age/sex class. To investigate this, we deliberately separated six animals, including the only two adult males, from each of two social groups. We hypothesized that only the adult males would embrace upon reintroduction. When two males were consecutively reintroduced to their group, they typically ran to each other and came together in a frontal embrace, emitting stereotyped vocalizations. No other combination of animals showed this ''reunion display.'' Though dramatic, this behavior was in no way associated with incidents of aggression. We argue affiliative bonds may exist in these tufted capuchin male dyads. (C) 1996 Wiley-Liss, Inc.