Considered signs of decreased welfare-abnormal behaviors such as self-injury and self-abuse among nonhuman primates housed in the laboratory-may put into question the validity and reliability of scientific research using these animals as models. Providing environmental enrichment decreases the incidence of some undesirable behaviors but is often unsuccessful at ameliorating the most severe types of abnormal behaviors. To prevent such behaviors from developing, it is important to identify risk factors that provide insight into the causes of certain abnormal behaviors. This study confirmed previous research identifying nursery rearing, single housing, and time spent in single housing as important risk factors. Results also indicate that the number of cage relocations affects the development of these behaviors. In addition, this study presents new data on comorbidity of several abnormal behaviors and discusses possible reasons for these patterns.A variety of factors influence the early development of abnormal behaviors in nonhuman animals in captivity, but disruption of early rearing experience in captive nonhuman primates seems to be the most important factor contributing to the development of behavioral problems (Bellanca & Crockett, 2002;Lutz & Novak, 2005;Lutz, Well, & Novak, 2003;Novak, 2003;Novak & Petto, 1991;Novak & Suomi, 1988). This was first demonstrated by Harlow's classic study on the effects of early social isolation on infant rhesus macaque behavior (Harlow & Zimmermann, 1959). Self-injurious behavior and noninjurious self-abuse can develop when appropriate physical contact is restricted or deprived during the first months of life. Rearing infants in a nursery setting versus with their mothers seems to predispose them to the development of abnormal behaviors (Lutz et al., 2003;Novak, 2003). Previous studies indicate that other risk factors for abnormal behavior such as stereotypic behavior (motor, postural, self-stimulation) include individual housing, long time in individual housing, and high number of blood draws (Lutz et al., 2003;Novak, 2003 HHS Public Access Author Manuscript Author ManuscriptAuthor Manuscript Author Manuscript through bouts of self-injury, including severe self-biting, hair-plucking, or head-banging. These injuries can be severe enough to require veterinary care and represent a serious issue in nonhuman primate care.Remediation for abnormal behavior in nonhuman primates spans from simple manipulanda and foraging devices to increased socialization. The degree to which these enrichment strategies promote species-typical behavior and ameliorate abnormal behavior depends upon the type of abnormal behavior exhibited (Lutz et al., 2003;Lutz & Novak, 2005;Novak, 2003). Generally, enrichment devices such as chew toys, foraging devices, and mirrors are provided to offer species-appropriate sensory stimuli and distract animals from engaging in abnormal behaviors. Whether these devices actually improve the psychological well being of the animal cannot be known directly; however, ...

Studies on early development have demonstrated the profound effects of early social experience on the behavioral development and physiology of young rhesus macaques. Given these relationships, we hypothesized that rhesus macaques exposed to different nursery-rearing conditions may develop unique biobehavioral profiles. If this is true, the assessment of temperament may allow us to pinpoint successful rearing environments, thus improving the overall health of non human primates that are raised in captive environments. We conducted biobehavioral assessments in order to examine differences in the development of infants raised under four different peer-rearing conditions (continuous pairing, intermittent pairing, continuous pairing with partner rotation, and intermittent rotational pairing) and compared these animals with data from a mother-reared control group. Overall, continuous-rotationally paired animals were most similar to mother-reared controls on most behavioral and temperament measures, suggesting that more socially complex rearing environments (greater number of social partners) favor a more active behavioral style. Cortisol profiles of mother-reared controls were similar to both continuous pairing groups, and these three groups had higher cortisol concentrations than the intermittent rotational-pairing group. In addition, intermittently paired infants displayed a significantly higher frequency of self-stroke behavior during a human intruder challenge, an abnormal behavior also known as floating limb which has been shown to be a precursor of self-biting. Overall, the data are consistent with the idea that social complexity in the nursery, as operationalized in our continuous rotational pairing, leads to a biobehavioral profile that is most similar to that of infants raised by their mothers in large, socially complex, cages.

Many captive primate facilities house rhesus macaques in multimale-multifemale social groups in large enclosures that simulate the natural social and environmental features characteristic of the species, enhancing their reproductive performance as well as their psychological well-being, yet one of the most difficult management problems in socially housed macaques is their propensity for exhibiting spontaneous bouts of deleterious aggression. To address this management problem, an automated bioacoustic monitoring system might be developed that is capable of detecting and forecasting problematic patterns of contact aggression. To evaluate the utility of this approach, this study examined the magnitude of aggression and the co-occurrence of certain vocalization types and aggression in 10 groups of rhesus macaques. The data confirmed aggression as a significant problem in rhesus groups and indicated that certain patterns of vocalizations are indicative of the type or level of aggression. The detection and classification of these vocalization types need further research to eventually design and implement an efficacious bioacoustic system for monitoring aggression in rhesus macaques.