Compete to Play: Trade-Off with Social Contact in Long-Tailed Macaques (Macaca fascicularis)

Abstract

Many animal species engage in various forms of solitary object play, but this activity seems to be of particular importance in primates. If playing objects constitute a valuable resource, and access to such objects is limited, a competitive context may arise. We inserted a unique toy within a mini-colony of long-tailed macaque (Macaca fascicularis) and compared their behaviors to sessions without playing object. An automatic color-based 3D video device was used to track the positions of each animal and the toy, and this data was categorized into 5 exclusive behaviors (resting, locomotion, foraging, social contact and object play). As expected, the delay to first access to the object reflected the hierarchy of the colony, indicating that a competition took place to own this unique resource of entertainment. In addition, we found that the amount of object play was not correlated with social or foraging behavior, suggesting independent motivational mechanisms. Conversely, object playing time was negatively correlated with idling time, thus indicating its relation to pastime activities. Interestingly, the amount of social contacts in the group was significantly reduced by the heightened competitive context, suggesting that competitors are more likely to be perceived as potential threat requiring caution, as shown in humans. Experimental manipulation of competitive contexts in primates reveals common mental processes involved in social judgment, and shows that access to valuable resources can be a sufficient cause for variations in group cohesion.

Effects of MDMA Injections on the Behavior of Socially-Housed Long-Tailed Macaques (Macaca fascicularis)

“…The effect of small doses of MDMA upon object play behavior could be interpreted in different ways, however the lack of data available on the hormonal correlates of solitary object play and the physiological consequences of small dose of MDMA injection makes it hard to distinguish among these. A possible explanation for the observed increase in object play at low MDMA doses could be a decrease of social fear, based on previous findings showing the influence of peers on object play [ 47 – 49 ]. However, the fact that small dose of MDMA has little impact on social contact or grooming behaviors is not in favor of this explanation.…”

Development of social systems neuroscience using macaques

“… 173 ) Using the tracking system, social behavioral changes caused by the introduction of an object (toy) in a group were reported. 174 ) Furthermore, the assessment of social behavioral changes induced by drug injections has also been started under group settings. 175 ) Further refinements of experimental procedures, for both behavioral and neural data collection, are expected with technological advancements.…”

Captive Conditions of Pet Lemurs in Madagascar

“…Not all enrichment, however, results in positive behavioral change and this, therefore, requires testing [Shepherdson, 1998;Mehrkam and Dorey, 2015]. For example, group cohesion in longtailed macaques ( Macaca fascicularis ) can be disrupted when a single toy is introduced into the captive environment, thereby causing competition [Ballesta et al, 2014], while multiple enrichment strategies (spatial, structural, lighting, and object enrichment) for captive Galago senegalensis had no effect on behavioral profiles [Schaefer and Nash, 2004]. Nevertheless, given that most pet lemurs in this study were housed alone, enrichment could be one method for increasing the quality of captive conditions in cases where owners do not have the capacity to provide social housing.…”