Self‐Injurious behavior in rhesus macaques: Issues and challenges

Abstract

Some monkeys housed in research facilities develop abnormal behavior ranging from stereotypic to the more serious condition of self-injurious behavior (SIB).We initially sought to understand how and why monkeys engaged in SIB and more importantly why only a small percentage of laboratory monkeys, with seemingly similar housing and background, developed this disorder. Of particular importance was the recognition that different pathways might lead to SIB and that strong individual differences would affect the manifestation of this disorder and the response to treatment. We developed a comprehensive plan to identify effective treatment and prevention strategies. We started with characterizing the disorder in terms of prevalence and types of environments in which it was found. We then conducted observations on a cohort of SIB and control monkeys to identify conditions associated with SIB (e.g., disordered sleep) as well as clinical disease states and congenital defects that could be precipitating factors.We examined the environmental events that triggered episodes of SIB in monkeys with the disorder and evaluated three models that might explain the reinforcement contingencies associated with SIB, including tension reduction, self-stimulation, and social communication. Possible treatments for SIB such as environmental enrichment, social housing, and pharmacotherapy were tested by our group and others. To date, no single treatment has been found to abolish SIB, and each of these treatments is impacted by individual differences. To develop possible prevention strategies, we examined colony management and health records to find risk factors for SIB. These risk factors generalized to other facilities, and considerable effort was expended by all behavioral managers at these facilities to reduce early life stress exposure, to minimize the length of individual cage housing by emphasizing pair housing, and to reduce the possible stressfulness of various veterinary/medical procedures by implementing positive reinforcement training.

Nonhuman primate abnormal behavior: Etiology, assessment, and treatment

“…A behavior in which an individual either causes, or has the potential to cause, a self‐inflicted injury that may require veterinary care; however, actual injury is relatively rare (Anderson & Chamove, 1980; C. Lutz et al, 2003; M. A. Novak, 2003; M. A. Novak, 2020). Examples of SIB include head banging, self‐biting, self‐hitting/slapping, and wounding due to aggressive hair plucking, and excessive wound picking (Bauer & Baker, 2016; Crast et al, 2014; Gottlieb, Capitanio, et al, 2013; Hosey & Skyner, 2007; C. K. Lutz, 2018; C. Lutz et al, 2003; Rommeck, Anderson, et al, 2009), with wounding severity differing markedly across individuals (Z. T. Freeman, Krall, et al, 2015; M. A. Novak, 2020).…”

“…Animals often resume the abnormal behavior after they have become habituated to the enrichment (in the case of toys) or after it has served its purpose (i.e., there is no more food present in the case of a puzzle ball). Further, while relatively useful for treating abnormal repetitive behaviors, at least in the short term, enrichment is less effective as a treatment for SIB (Novak et al, 1998; see also M. A. Novak, 2020).…”

“…Baker, 2016;Crast et al, 2014;Gottlieb, Capitanio, et al, 2013;Hosey & Skyner, 2007;C. K. Lutz, 2018;Rommeck, Anderson, et al, 2009), with wounding severity differing markedly across individuals (Z. T. Freeman, Krall, et al, 2015;M. A. Novak, 2020).…”

Automatically detecting stereotyped behaviors from surveillance videos of zoos and animal reserves for captive animal welfare

“…Wagner et al observed the behavior of capuchin monkeys in the public Zoo of Vers-Duifen, Brazil, for 40 days to determine the frequency of stereotypical behavior and self-orientation and to analyze the effects on behavioral stability [12]. In addition to zoos, the stereotypical behavior of monkeys in research facilities was observed and analyzed [13]. These observations and analyses were made by looking at video recordings of animal behavior and then analyzing them.…”

A Rhesus Monkey Model of Non-suicidal Self-Injury

“…The rationale for evaluating the rhesus monkey model of SIB is based, in part, on disturbing trends showing that NSSI is on the rise among teenagers and young adults ( Wester et al, 2018 ) and on significant animal welfare concerns for non-human primates with this condition ( Novak, 2020 ). Humans and Old World monkeys such as rhesus macaques share many important features including a long lifespan, complex social structures, higher order cognitive processes, large brains in relation to body size, and hands adapted for manipulation of objects.…”