Positive Reinforcement Training Moderates Only High Levels of Abnormal Behavior in Singly Housed Rhesus Macaques

Abstract

This study evaluated the application of positive reinforcement training (PRT) as an intervention for abnormal behaviors in singly housed laboratory rhesus macaques at 2 large primate facilities. Training involved basic control behaviors and body-part presentation. The study compared baseline behavioral data on 30 adult males and 33 adult females compared with 3 treatment phases presented in counterbalanced order: 6 min per week of PRT, 20 or 40 min per week of PRT, and 6 min per week of unstructured human interaction (HI). Within-subject parametric tests detected no main or interaction effects involving experimental phase. However, among a subset of subjects with levels of abnormal in the top quartile of the range (n = 15), abnormal behavior was reduced from 35% to 25% of samples with PRT but not with HI. These results suggest that short durations of PRT applied as enrichment for this species and in this context may not in itself be sufficient intervention for abnormal behavior because levels remained high. However, it may be appropriate as an adjunct to other interventions and may be best targeted to the most severely affected individuals.

The use of positive reinforcement training to reduce stereotypic behavior in rhesus macaques

“…Training was found to reduce the incidence of stereotypies in polar bears (D. Shepherdson, personal communication), and primate species (Morgan et al, 1993; Raper et al, 2002; Bourgeois and Brent, 2005; Pizzutto et al, 2007; Baker et al, 2009) but was not effective in others (Bloomsmith et al, 2005). The latter study was looking at the effects of PRT on abnormal behavior in general, and included self-injurious and self-directed behaviors.…”

“…PRT can improve the relationship between caretakers and subjects (Bloomsmith, 1997). Further, PRT has been shown to reduce abnormal behaviors including self-directed behaviors (Laule, 1993; Bloomsmith et al, 2007), although this is not a universal finding (e.g., Bloomsmith et al, 2005, Baker et al, 2009). While PRT may not be a universal panacea for stereotypic behavior, it may be useful as a therapy, at least for some individuals.…”

Social buffering in adult male rhesus macaques (Macaca mulatta): Effects of stressful events in single vs. pair housing

“…Compared to singly housed controls, paired females have lower infant mortality and higher infant weight gain, and paired monkeys have been shown to receive fewer veterinary treatments [18, 35]. While efforts have been made to enrich the environment of captive non‐human primates through interaction with humans via positive reinforcement training, there is no evidence that positive interaction with humans has the same beneficial effect as a conspecific social companion [1, 2].…”

A response to the influence of observer presence on baboon (Papio spp.) and rhesus macaques (Macaca mulatta) behavior: A comment on

“…As a percentage of total time points, this represents 5.95%. While Hawkins claims this level to be high, it is actually lower than the amounts of abnormal behavior expressed by macaques in similar housing situations at other facilities; 19.6% (Baker et al, 2009), 436 s/1800 s or 24.2% (Bayne et al, 1991). …”