Severe Intragroup Aggressions in Captive Common Marmosets (Callithrix jacchus)

Abstract

Members of captive colonies of common marmosets (Callithrix jacchus), a small New World primate, can occasionally be victims of repeated, and potentially fatal, attacks by a family-mate. This study examined the records of a colony, looking for past instances of such aggressions. The aim was to better understand the possible causes underlying this phenomenon and to identify variables that could minimize their occurrence. The results showed that both males and females behaved as aggressors at the same rate, but females attacked just females, whereas males attacked both males and females. Most aggressions involved siblings and occurred at a higher rate when the cages were occupied by more than 5 nonhuman animals. The influence of group size was significant only when females behaved as aggressors. This study suggests that several factors can determine the occurrence of these aggressions and that their relative importance depends on the sex of the aggressor. The results of this study highlight the importance of collecting further data to verify whether crowding in a confined space, rather than group size per se, affects the incidence of these aggressions.

The Effect of Crowding on the Social Behavior of the Cooperatively Breeding Cotton-Top Tamarins (Saguinus oedipus)

“…We found that aggression increased between fathers and sons, and especially between mothers and daughters. Breeding females frequently evict the eldest female helper from their natal group in cotton-top tamarins (Price and McGrew 1991;Sánchez et al 2002), and the risk of eviction increases with group size in common marmosets, particularly in the case of females (de Filippis et al 2009). However, our large groups had 4 and 6 additional helpers whereas in groups with few helpers, in which cohesion and stability are likely to be extremely important to breeders to ensure adequate infant care, breeders would be expected to use preconflict management strategies.…”

“…Schaffner et al 2005) and in male-male dyads of cotton-top tamarins (Peñate et al 2009) may indicate that aggression can damage relationships. Further, escalated aggression sometimes leads to the eviction of helpers from the group (Inglett et al 1989;McGrew and McLuckie 1986;Sutcliffe and Poole 1984), especially when the size of captive groups reaches the maximum size observed in wild populations (de Filippis et al 2009;Snowdon and Pickhard 1999). Group size and helper availability seem to be important factors in the regulation of social interactions, with the value of helpers being reduced and conflicts more disruptive in larger groups (Aureli and Schaffner 2006;Schaffner and French 1997).…”

Behavioral responses to social separation stressor change across development and are dynamically related to HPA activity in marmosets

“…While the reasons for these sex differences are unclear, it may be explained by sex‐differential group emigration patterns. Not only are subordinate females more likely to participate in extragroup interactions [marmoset, Lazaro‐Perea, ], but they are also more likely to be the target of aggression, especially as group size increases [marmoset, De Filippis et al, ; Snowdon & Pickhard, ]. Furthermore, group fission is more likely to occur when resource competition and environmental stress are high [toque macaque, Dittus, ].…”

Promoting Good Nonhuman Primate Welfare outside Regular Working Hours

“…It is important to monitor the behaviour of the colony during the night in the case of social expulsion, as the expelled individual could be prevented from sleeping in the nest with the others (personal observation Augusto Vitale) or wounded when shut in smaller overnight quarters where it is not as easy to get away from aggressors (personal communication Max Norman). Alternative nesting sites should be provided in these cases (De Filippis et al, 2009 [ 100 ]), as well as enough space and escape routes for animals to get away if they need to.…”