Floating limb behaviors and self‐biting are associated in laboratory monkeys

Abstract

Early descriptions of floating limb behaviors in monkeys were associated with isolation rearing, a practice that ended more than two decades ago. The present authors named various forms of behaviors in which a leg is elevated for no apparent reason: "Floating Limb Suite" (FLS). Floating limb behaviors, identified in laboratory monkeys at the Washington National Primate Research Center (WaNPRC), consist of two subcategories distinguished by whether monkeys seem to react to the elevated leg or ignore it. Given the past association of isolation rearing with both self-biting (SB) and floating limb, the investigators predicted that SB and FLS would be associated in monkeys not reared in isolation. The investigators tracked, over a period of 3 years, the presence of FLS and SB in macaques (Macaca nemestrina, M. fascicularis, M. mulatta) and Papio cynocephalus at WaNPRC. SB and both subcategories of FLS occurred in mother-reared and surrogate-peer-nursery-reared monkeys. We analyzed presence of FLS, the two subcategories of FLS, and SB in 1,117 macaques monitored for up to 3 years, and 781 macaques observed for 8 min of structured data collection. The Papio sample size was insufficient for statistical analysis. Both sampling methodologies found FLS and FLS subcategories to be associated with SB. Nearly half the monkeys only engaging in seemingly harmless nonreactive forms of FLS also performed the potentially injurious behavior of self-biting. The positive association between FLS and SB suggests that monkeys exhibiting one of these behaviors are at a heightened risk for developing the other. One impediment to studying floating limb behaviors is lack of consensus on definitions. This study defined seven forms of apparently functionless elevated limb behaviors. Continued research on factors associated with floating limb behaviors across demographic groups and settings may provide insights into the etiology and treatment of self-biting.

Early social experience affects behavioral and physiological responsiveness to stressful conditions in infant rhesus macaques (Macaca mulatta)

“…Floating limb behavior consists of a peculiar behavioral pattern defined in our most recent paper as: “A limb moving seemingly of its own accord, in that the animal is not attending to or even aware of limb movement; often incorporates a slow stroking of the animal’s own body” [Rommeck et al 2009b]. While this behavior does not cause physical harm to the animal, it has been associated with [Bentson et al 2010; Bentson et al 2005] and even shown to be predictive of [Rommeck et al 2009b] self-biting in rhesus macaques. The present result is consistent with our previous finding of a significant overall increase in floating limb behavior with an intermittent pairing strategy.…”

Rehabilitation and Socialization of Chimpanzees (Pan troglodytes) Used for Entertainment and as Pets: An 8-Year Study at Fundació Mona

“…Prolonged captivity, sensory deprivation, and use in laboratories have been shown to contribute to behavioral pathologies in nonhuman primates (Anderson 2010;Bellanca and Crockett 2002;Bradshaw et al 2008;Kalcher et al 2008;Llorente and Campi 2014;Novak 2003;Rodríguez-Rodríguez et al 2010), including abnormal behaviors such as floating limb (Bentson et al 2010), self-biting (Reinhardt and Rossell 2001), self-injury (Wielebnowski et al 2002), self-clasping (Buttelmann et al 2008), pacing (Rybiski Tarou et al 2005), rocking (Lopresti-Goodman et al 2012), object attachment (Janson 2012), coprophagy (Nash et al 1999), and regurgitation-reingestion (Baker and Easley 1996). Poor conditions early in life may also affect personality (Martin 2005) and the development of mental disorders later in life (Brüne et al 2004;Ferdowsian et al 2011Ferdowsian et al , 2012Troisi, 2005).…”

Astrocyte Atrophy and Immune Dysfunction in Self-Harming Macaques

“…We have recently used a nonhuman primate model for self-harm: self-injurious behavior (SIB) in rhesus macaques. Approximately 5–13% of the caged population spontaneously demonstrate SIB in the form of self-biting [9], [10]. While self-biting may appear severe to an observer, skin trauma is atypical.…”