Stereotypies in polar bears

The spatial and temporal patterns of stereotypies in three captive polar bears (Ursus maritimus) were analysed. There was considerable variation in the time budgets of the three animals: stereotypies made up 16.0%, 24.4 %, and 76.5 % of the observation time between 8.00 A.M. and 4.00 P.M. Stereotyped walking or swimming bouts were of significantly longer duration than variable walking or swimming bouts. Seventy-five bouts of stereotyped walking were observed in detail to test the hypothesis that stereotypies can reduce arousal level. The bouts were composed of regular laps. At a given site, each lap consisted of a fixed number of steps, and there was little variation in the duration of a lap. In one individual the walking speed decreased significantly in the course of stereotyped walking bouts. Generally, however, stereotyped walking bouts were not preceded by high activity levels and followed by low activity levels. Stereotyped walking was regularly associated with yawning and tongue-flicking. Qualitative observations suggest that polar bears remain attentive while stereotyping. It is hypothesized that stereotyped walking in polar bears does not originate from frustrated migratory activity, but from frustrated appetitive behavior.     

Successful feeding enrichment for captive chimpanzees

An analysis of a feeding enrichment program for captive chimpanzees was completed to determine the effects of that program on the incidence of agonistic and abnormal behaviors by using 41 adult chimpanzees in six social groups. Four feeding enrichment procedures were implemented simultaneously in the experimental phase of this ABA design study. The procedures were planned to elicit time-consuming, noncompetitive feeding, theorizing a consequent reduction in agonism and detrimental abnormal behaviors typically occurring in captive chimpanzees. The 270 hours of data were collected over a 6-month period. A multivariate analysis of variance result supported the hypothesis, as the barrage of feeding enrichment techniques significantly reduced agonism and abnormal behaviors. This study's significance lies in its application of the scientific method to improving the husbandry of captive primates.     

Cerebral palsy in a macaque monkey

Magnetic resonance imaging was used to document brain lesions symptomatic of cerebral palsy in the macaque monkey exhibiting poor motor control and periodic episodes of ocular nystagmus and convulsive twitching. Neuroanatomic deficits most likely resulted from hemorrhage or ischemic infarction at or near the time of birth. Extreme maternal dependency and retarded behavioral development were documented at 3 and 12 months of age. Both social and motor behavior improved significantly when observed at 30 months of age after therapy.     

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

Background The purpose of this study was to test whether long‐term pair housing of male rhesus macaques ameliorated negative responses to stressful events that can occur in the course of routine husbandry or research procedures. Methods Twelve singly housed individuals were videotaped during two potentially stressful events before and after social introduction into pairs. During each stressor, abnormal behavior and anxiety‐related behavior were quantified from videotape. Results When visually exposed to the restraint and anesthesia of other monkeys, subjects showed significantly reduced frequencies of abnormal behavior when pair‐housed in comparison to their reactions when housed singly. Noisy and disruptive conversation between technicians standing immediately in front of the subjects’ cage did not elicit the same reduction in abnormal behavior. Neither test showed a significant difference across housing settings for anxiety‐related behaviors. Conclusions These findings suggest that pair housing buffers adult male rhesus macaques against common stressors in the laboratory setting.     

Psychological well-being in paired adult female rhesus (Macaca mulatta)

We assessed the effects of social living (pairing) on improving the psychological well-being of adult female rhesus macaques (Mucuca mulutta) housed under laboratory conditions. We measured well-being in 12 pairs and 12 singly housed females through multiple indices of health (hematology, clinical morbidity, and body weight), stress (immune responses), behavior (preferences for social proximity, exhibition of species typical affliative behavior, and rates of abnormal behavior), and reproduction (frequency of ovulation, rates of conception, and infant survival). We selected adult females that had been living in single-unit cages and paired them in larger cages. Care was taken to allow females to become familiar with one another before pairing took place, and pairs that fought were separated before serious injuries occurred. Singly-housed control females were also paired for 1 week and then separated to balance the stressful effects expected to occur during the initial pairing and to assure that they were equivalent to the experimental animals in their ability to live socially. We concluded that pairing adult female rhesus monkeys was a positive experience for both the dominant and subordinate members of the pairs. They chose to spend the majority of their time involved in amicable social interactions, were more active, and they indulged in less nail biting than singly-housed controls. There were no differences in reproduction, rates of clinical morbidity, or immune stress responses among the groups. However, pairing alone may not be sufficient to assure the well-being of laboratory-housed rhesus macaques, because rates of abnormal behaviors such as stereotyped movements remained high. © 1994 Wiley-Liss, Inc.