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Published on: June 5, 2019
Factors predicting increased incidence of abnormal behavior in male pigtailed macaques
Rita U Bellanca1, Carolyn M Crockett
1National Primate Research Center, University of Washington, Seattle, Washington 98195, USA.
Abstract:
To identify factors predicting abnormal behavior in laboratory monkeys, we observed all available singly housed 4- to 11-year-old male pigtailed macaques (Macaca nemestrina), the species/age/sex group most likely to be referred to the Washington National Primate Research Center's Psychological Well-Being Program for behavioral assessment. Of the 87 subjects, 29 had been referred to the program whereas 58 had not. Abnormal behavior was unrelated to the subject's housing location (biocontainment vs. other facility) or invasiveness of research. Nursery-reared subjects displayed more abnormal behavior than mother-reared subjects. Across and within rearing categories, the proportion of the first 48 months of life spent singly housed was positively related to the amount of abnormal behavior at maturity. This effect was stronger for subjects separated from the mother for clinical rather than experimental reasons, and least for mother-reared subjects. Locomotor stereotypy, by far the most frequent form of abnormal behavior, was positively related to time in single housing but was unrelated to rearing. These results reinforce the importance of tactile social contact during juvenility for the prevention of abnormal behavior in social primates. They also suggest that self-directed abnormal behaviors and locomotor stereotypies have different etiologies.
Insights
Early single housing in pigtailed macaques (Macaca nemestrina) predicts later abnormal behavior. Social contact during youth is crucial for preventing behavioral issues in primates.
Area of Science:
- Primate behavior
- Animal welfare science
- Veterinary behavioral medicine
Background:
- Abnormal behaviors in captive primates can impact welfare and research outcomes.
- Pigtailed macaques (Macaca nemestrina) are a relevant model for studying primate behavior due to their susceptibility to behavioral issues.
- Understanding factors contributing to abnormal behavior is essential for improving captive animal care.
Purpose of the Study:
- To identify predictors of abnormal behavior in adult male pigtailed macaques.
- To investigate the influence of early life experiences, specifically housing and rearing, on the development of abnormal behaviors.
- To differentiate the etiologies of self-directed abnormal behaviors and locomotor stereotypies.
Main Methods:
- Observation of 87 singly housed male pigtailed macaques (Macaca nemestrina) aged 4-11 years.
- Assessment of abnormal behavior prevalence and types, including locomotor stereotypy.
- Analysis of factors such as housing location, research invasiveness, rearing history (nursery vs. mother-reared), and duration of early single housing.
Main Results:
- Abnormal behavior was not linked to housing location or research invasiveness.
- Nursery-reared macaques exhibited more abnormal behavior than mother-reared macaques.
- Increased duration of single housing in the first 48 months of life positively correlated with abnormal behavior in adulthood, particularly for clinically separated subjects.
Conclusions:
- Early life social contact, specifically tactile contact during juvenility, is vital for preventing abnormal behavior in primates.
- The duration of early single housing is a significant predictor of abnormal behavior.
- Locomotor stereotypies and self-directed abnormal behaviors may stem from different underlying causes.
