Socialization in pigtailed macaques (Macaca nemestrina).

In response to new emphasis by regulatory agencies regarding socialization, behavioral management programs are allocating greater resources to maximize socialization opportunities for laboratory primates. Information regarding predictors of compatibility and risk of injury for all laboratory-housed species of macaques are needed to make social introductions and pairings as efficient and safe as possible. This study presents data on 674 pairs of pigtailed macaques (Macaca nemestrina) at the Washington National Primate Research Center over a 7-year period. During pair introduction, behavior was monitored while the degree of tactile contact was gradually increased. Based on observed behavior, pairs were assigned a behavioral introduction score (BIS), rating the quality of their interactions for each day of introduction. Animals deemed compatible, based on the BIS and technologist judgment, were allowed to progress to continuous contact with no staff present. A small proportion of animals deemed compatible at introduction was later separated for subsequent incompatibility or aggression; these proportions were higher in full contact compared to protected contact pairings. Of 674 pairs, 75% were deemed compatible at introduction in protected contact; 86 of these pairs were later transitioned to full contact with 98% compatibility. Predictors of decreased compatibility assessed during protected contact introductions included age (adult pairs were less compatible), the BIS on the last day of introduction, and aggression or injury during the introductory period. Predictors of injuries during the protected contact introduction process included: aggression on the first day of introduction, a negative BIS on the first or last day of introduction, and, surprisingly, the presence of grooming on the first day of introduction. Injuries during both introduction and subsequent pairing in protected contact were rare; however, injury rates increased significantly during full-contact pairing. These findings underscore the necessity of species-specific data to guide decision-making during the social introduction process. Am. J. Primatol. 79:e22556, 2017. © 2016 Wiley Periodicals, Inc.

Tenure in current captive setting and age predict personality changes in adult pigtailed macaques.

Personality change in nonhuman primates is a topic that warrants more research attention. Many studies focus on intraindividual repeatability, but few note population-wide trends in personality change. In part, this results from the large sample size that is required to detect such trends. In the present study, we measured personality in a large sample (N = 293) of adult, mother-reared pigtailed macaques, Macaca nemestrinam, over a period of 3 years. We looked at four personality components (sociability towards humans, cautiousness, aggressiveness and fearfulness) derived from behavioural observations at two to four time points per subject. We found these components to have repeatabilities similar to those reported elsewhere in the literature. We then analysed population-wide changes in personality components over time using a linear mixed effects model with three predictors: entry age at the current primate facility, tenure at the primate facility at the time of the first personality test and time elapsed since the first personality test. We found that adult personality changed with life experiences (here, tenure at the facility where tested) and age. Throughout adulthood, pigtailed macaques became less cautious and more aggressive. At the same time, subjects became less cautious and more sociable with increasing time in individual caging at the current primate research facility. We also found that individuals differed significantly in their personality consistency. Other researchers may benefit by applying similar methodology to that described here as they extrapolate about personality measures over time.

Temperament in rhesus, long-tailed, and pigtailed macaques varies by species and sex.

Temperament differs among individuals both within and between species. Evidence suggests that differences in temperament of group members may parallel differences in social behavior among groups or between species. Here, we compared temperament between three closely related species of monkey-rhesus (Macaca mulatta), long-tailed (M. fascicularis), and pigtailed (M. nemestrina) macaques-using cage-front behavioral observations of individually housed monkeys at a National Primate Research Center. Frequencies of 12 behaviors in 899 subjects were analyzed using a principal components analysis to identify temperament components. The analysis identified four components, which we interpreted as Sociability toward humans, Cautiousness, Aggressiveness, and Fearfulness. Species and sexes differed in their average scores on these components, even after controlling for differences in age and early-life experiences. Our results suggest that rhesus macaques are especially aggressive and unsociable toward humans, long-tailed macaques are more cautious and fearful, and pigtailed macaques are more sociable toward humans and less aggressive than the other species. Pigtailed males were notably more sociable than any other group. The differences observed are consistent with reported variation in these species' social behaviors, as rhesus macaques generally engage in more social aggression and pigtailed macaques engage in more male-male affiliative behaviors. Differences in predation risks are among the socioecological factors that might make these species-typical behaviors adaptive. Our results suggest that adaptive species-level social differences may be encoded in individual-level temperaments, which are manifested even outside of a social context. Am. J. Primatol. 75:303-313, 2013. © 2012 Wiley Periodicals, Inc.

Comparing the relative benefits of grooming-contact and full-contact pairing for laboratory-housed adult female Macaca fascicularis.

Tactile social contact is the most effective form of environmental enrichment for promoting normal behavior in captive primates. For laboratory macaques housed indoors, pair housing is the most common method for socialization. Pairs can be housed either in full contact (FC), or in protected contact (PC). At Washington National Primate Research Center, PC is provided by grooming-contact (GC) cages whereby two partners are housed individually in adjacent cages with access to each other through widely spaced vertical bars. Grooming-contact has been used to accommodate research protocol restrictions and improve the likelihood of compatibility for various pairings, in part by enabling male-female pairs. This study compares the benefits between the two housing types by video recording 14 pairs of adult female Macaca fascicularis in four sequential housing phases following an ABBA design: baseline grooming-contact, full contact shortly after introduction, 1-month-later full contact, and after reversion to grooming-contact. Prior to this study, pairs had been housed compatibly in GC. Twelve of the 14 long-term pairs transitioned successfully to full contact and data presented exclude the two failed pairs. Allogrooming increased significantly when pairs first switched from GC to FC (P = 0.018), but the effect did not last through the on 1-month-later FC phase suggesting that the initial improvement in affiliative behavior was a transitory novelty response that did not persist. Self-grooming significantly decreased between the first GC and first FC phases (P = 0.016), likely due to redirected allogrooming. Non-contact affiliative behavior towards partner or other conspecifics in the room did not differ, nor did agonism towards partner or others in the room. Occurrence of abnormal, tension, manipulation, miscellaneous active, and inactive behaviors did not differ significantly across housing phases. Proximity measurements indicated that pairs were significantly out of arm's reach more often in protected contact than when in full contact (P ≤ 0.02). Proportion of time spent in physical contact significantly increased between the first GC and first FC phases (P = 0.002), but subsequently declined. For both FC phases, partners chose to spend about 50% of their time in the same cage. Few behavioral improvements were seen after pairs switched to full contact and no negative effects came of reversion to grooming contact. This study suggests that tactile contact provided through widely spaced bars (grooming-contact) is a viable alternative to full contact housing for adult female longtailed macaques. It provides a degree of social housing while allowing both partners choice and control, key concepts in contemporary animal welfare guidelines.

Pair housing for female longtailed and rhesus macaques in the laboratory: behavior in protected contact versus full contact.

Pair housing for caged macaques in the laboratory generally allows unrestricted tactile contact but, less commonly, may involve limited contact via grooming-contact bars or perforated panels. The purpose of using this protected contact housing, which prevents entry into pair-mates' cages, typically is to accommodate research and management requirements. The study used behavioral data collected on 12 pairs of female longtailed macaques (Macaca fascicularis) at the Washington National Primate Research Center and 7 pairs of female rhesus macaques (Macaca mulatta) housed at the Tulane National Primate Research Center to assess the relative benefits of protected versus full protected contact. The study collected data in stable pairs housed first in protected contact followed by full contact. Species combined, the study found the presence of the panel was associated with lower levels of social grooming and higher levels of self-grooming, abnormal behavior, and tension-related behavior. Within species, only the protected- versus full-contact contrasts for abnormal and tension were statistically significant-and only for rhesus macaques. Results suggest that for female rhesus macaques, potential disadvantages or inconveniences of full contact should be balanced against the improved behavioral profile in comparison to protected contact. The use of protected contact among female longtailed macaques does not appear to require the same cost-benefit analysis.

Evaluating paint rollers as an intervention for alopecia in monkeys in the laboratory (Macaca nemestrina).

Adult female macaques (Macaca nemestrina) in the laboratory with alopecia from known or suspected overgrooming were subjects in a study evaluating effectiveness of a grooming device. The intervention evaluated was a paint roller on a metal bar hung on the cage, replaced weekly for 6 weeks. In a within-subjects design, 6 monkeys were randomly assigned to first experience the paint roller (PR) and later the control (C) condition (roller bar only); 6 monkeys were randomly assigned to C followed by PR. Coat condition scores quantifying alopecia were taken cageside weekly. During PR, PR use was scored 3 times a week based on wear. Alopecia scores during PR did not differ significantly from C. Although all the monkeys used the paint rollers, PR use scores did not correlate significantly with improvement in coat condition. Paint rollers do not appear to be an effective intervention for alopecia from overgrooming.

Floating limb behaviors and self-biting are associated in laboratory monkeys.

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.

Managing environmental enhancement plans for individual research projects at a national primate research center.

We describe a method for managing environmental enhancement plans for individual research projects at a national primate research center where most monkeys are assigned to active research projects. The Psychological Well-being Program (PWB) at the University of Washington National Primate Research Center developed an Environmental Enhancement Plan form (EEPL) that allows PWB to quantify and track changes in enrichment allowances over time while ensuring that each animal is provided with as much enrichment as possible without compromising research. Very few projects involve restrictions on toys or perches. Some projects have restrictions on food treats and foraging, primarily involving the provision of these enrichments by research staff instead of husbandry staff. Restrictions are not considered exemptions unless they entirely prohibit an element of the University of Washington Environmental Enhancement Plan (UW EE Plan). All exemptions must be formally reviewed and approved by the institutional animal care and use committee. Most exemptions from elements of the UW EE Plan involve social housing. Between 2004 and 2006, the percentage of projects with no social contact restrictions increased by 1%, but those prohibiting any tactile social contact declined by 7%, and projects permitting tactile social contact during part of the study increased by 9%. The EEPL form has facilitated informing investigators about the enrichment their monkeys will receive if no restrictions or exemptions are requested and approved. The EEPL form also greatly enhances PWB's ability to coordinate the specific enrichment requirements of a project.

Beta-endorphin levels in longtailed and pigtailed macaques vary by abnormal behavior rating and sex.

Frequent or severe abnormal behavior may be associated with the release of endorphins that positively reinforce the behavior with an opiate euphoria or analgesia. One line of research exploring this association involves the superhormone, proopiomelanocortin (POMC). The products of POMC appear to be dysregulated in some human subjects who exhibit self-injurious behavior (SIB). Macaque monkeys have POMC very similar to humans, and some laboratory macaques display SIB or frequent stereotypies. We investigated associations between plasma levels of three immunoreactive POMC fragments with possible opioid action and abnormal behavior ratings in macaques. In 58 adult male and female macaques (24 Macaca fascicularis and 34 Macaca nemestrina), plasma levels of intact beta-endorphin (betaE) and the N-terminal fragment (BEN) were significantly higher in animals with higher levels of abnormal behavior. The C-terminal fragment (BEC) was significantly higher in males but unrelated to ratings of abnormal behavior. Levels of ACTH, cortisol, and (betaE-ACTH)/betaE dysregulation index were unrelated to abnormal behavior. None of the POMC products differed significantly by subjects' species, age, or weight. The finding that intact beta-endorphin is positively related to abnormal behavior in two species of macaque is consistent with some previous research on human subjects and nonprimates. The positive relation of the N-terminal fragment of betaE to abnormal behavior is a new finding.

Communicative contexts of the LEN facial expression of pigtailed macaques (Macaca nemestrina).

We have investigated the contexts of the LEN (lips forward-ears back-neck extended) or pucker, a species-specific facial expression of Macaca nemestrina, in four breeding groups. Using the behavior sampling method we recorded all LENs, associated behavior, and the identities of the individuals involved. Of 401 LENs initiated, 62% were directed to the observer, who never responded to them in any way. Infants and dams directed more LENs to the observer than did sires or other females. The average intraspecific LEN rate was 0.82 per monkey-hour, including LENs given in reciprocation. Excluding LENs given in reciprocation, sires LENned significantly more often to females and dams than to infants, and significantly more than females and dams LENned to them. Of LENs directed to conspecifics, 21% were reciprocated, 34% were followed by distance reduction, and 16% led to both. Reciprocating LEN responses occurred more often to LENs initiated by sires. Although primarily affiliative, some LENs occurred in agonistic contexts, suggesting a possible appeasing function or rejection of a LEN's social invitation. Aggression preceded 8% of conspecific LENs, and 15% of LENs were responded to by visual aggression. No response followed 47% of LENs. Affirming the conclusions of others, LENs are often directed by males to females before mating. LENs directed at cradled infants suggest that maternal LENs serve more than a summoning function. LENs directed to people by M. nemestrina usually seem to be inviting interaction or attention, but LENs by dams seem to reflect concerns over their infants. We speculate that at the most basic level the LEN emphasizes that the sender's gaze is fixed on the receiver. We propose that the LEN may have evolved in this quiet rainforest species to facilitate coordination of social activity when silence or stealth is advantageous.

Survey of environmental enhancement programs for laboratory primates.

Animal welfare regulations in the United States require that nonhuman primate environmental enhancement plans be made in accordance with currently accepted professional standards; however, little information is available for quantifying common practice. Here we report the results of a 2003 survey that was sent to individuals overseeing enrichment programs at a variety of primate research institutions. The surveys requested information on program administration and management, implementation standards, procedures, and constraints pertaining to major categories of environmental enrichment, as well as intervention plans for animals exhibiting behavioral pathologies. Data were obtained on the management of 35,863 primates in 22 facilities. Behavioral scientists performed program oversight at the majority of facilities. Most programs reported recent changes, most commonly due to external site visits, and least commonly resulting from internal review. Most facilities' institutional animal care and use committees (IACUCs) included of individuals with behavioral expertise, and about two-thirds reported that enrichment issues could influence research protocol design. While most primates were reported to be housed socially (73%), social housing for indoor-housed primates appears to have changed little over the past 10 years. Research protocol issues and social incompatibility were commonly cited constraints. Implementation of feeding, manipulanda, and structural enrichment was relatively unconstrained, and contributions to these aspects of behavioral management generally included individuals in a wide variety of positions within a facility. In contrast, enrichment devices were used on a less widespread basis within facilities, and positive reinforcement programs that involved dedicated trainers were rare. We suggest that altering the role of the IACUC would be a productive avenue for increasing the implementation of social housing, and that an emphasis on prevention rather than intervention against behavioral pathology is warranted. The data from this survey may be useful for anticipating future program evaluations, establishing more effective internal evaluations, and assessing program progress and resource allocation.

Successful introduction of Macaca nemestrina infants to their mothers after cesarean delivery.

Four Macaca nemestrina infants delivered via cesarean section were introduced to their mothers after surgery. All 4 introductions were successful, although methods differed slightly between dam-infant pairs. Pairs were considered successful when the mother displayed affiliative behavior towards the infant (including grooming), cradled it ventrally, and nursed it sufficiently to maintain infant health. The dams were sedated lightly with ketamine prior to introduction to reduce the possibility of aggression to caregivers and infants. The dams were checked for lactation, and each infant was swabbed with its placenta and with its mother's vaginal secretions prior to placement in the dam's cage. During the initial exposure, all 4 mothers picked up their infants within 1.5 h after introduction. Three of the 4 dam-infant pairs were fully successful during the initial exposure (24 h postdelivery), that is, the infants began to nurse within 2.5 h of affiliative contact. The 4th dam-infant pair required 3 d of successive exposures before the infant was nursed adequately. Infant health and maternal behavior determined the length of exposure. The optimal duration of these introductory encounters appeared to be between 2 and 3.5 h, to allow sufficient time for the dam's recovery from sedation while avoiding adverse effects on infant health. These observations demonstrate that cesarean-delivered M. nemestrina infants can be successfully united with their mothers, although it sometimes may require prolonged exposures on successive days.

Subacute necrotizing encephalopathy in a pig-tailed macaque (Macaca nemestrina) that resembles mitochondrial encephalopathy in humans.

A male pig-tailed macaque (Macaca nemestrina), approximately 5 years old, was found to be vision-impaired and to have profound behavioral abnormalities, including hyperactivity and self-injurious behavior that was not amenable to amelioration by environmental enrichment. Facial and skeletal dysmorphisms also were noted. Magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning revealed areas of possible infarction in the occipital lobes and megaventriculosis. At necropsy, following euthanasia for humane reasons, severe polio- and leukoencephalomalacia accompanied by megaventriculosis were seen in both occipital lobes and in several sulci of the parietal and frontal lobes. Light microscopic findings included loss of neocortical structure, with necrosis, neuronal loss, astrogliosis, vascular proliferation, mild spongiosis, and demyelination. The extent and severity of lesions were most pronounced in the occipital lobes and were greater in the left than in the right hemisphere. Other lesions included mild bilateral atrophy of the optic nerves, thymic involution, necrotizing dermatitis due to trauma, and a spectrum of spermatozoal abnormalities. The imaging and gross and light microscopic changes found in this animal resemble the mitochondrial encephalopathies of humans; this was corroborated by results of immunohistochemical analysis demonstrating decreased expression of enzymes of the mitochondrial oxidative complex ([OC]-I, -III, and -IV) in brain and muscle, and detection of fibrinogen immunoreactivity in neurons and glial cells. The spermatozoal defects may represent yet another aspect of a mitochondrial defect.

Factors predicting increased incidence of abnormal behavior in male pigtailed macaques.

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.

Mantled howler population of Hacienda La Pacifica, Costa Rica, between 1991 and 1998: effects of deforestation.

A survey of the mantled howler (Alouatta palliata) population on Hacienda La Pacifica, Guanacaste, Costa Rica, was done in July and August of 1998 to determine population parameters following deforestation due to major canal construction between 1990 and 1994. The survey was carried out in a manner identical to our 1991 survey and consisted of a single pass and two re-surveys of all forested areas of the farm. As canal construction effectively increased fragmentation of the habitat, we predicted decreased population and group size over this time. Results indicated that between the 1991 and 1998 survey, group size decreased but not significantly, and there were significantly fewer adult males and adult females per group. Population size, however, remained unchanged as there was an increase in animals in the immature age classes. An increase in the infant to adult female ratio suggests a stable or even expanding population, which could represent recovery from the initial disturbance of deforestation. Thus, despite changes in the forest and land use patterns, the area now appears to support the same number of howlers as found in previous surveys.

Modeling managed monkey populations: sustainable harvest of longtailed macaques on a natural habitat island.

Computer simulation of population dynamics can be useful in managing harvested populations of monkeys on islands. Between 1988 and 1991, 420 adult female and 58 adult male simian retrovirus-free Macaca fascicularis were released onto Tinjil Island, Indonesia, to provide the nucleus for a free-ranging breeding colony. Natural habitat breeding facilities are excellent alternatives to wild trapping and compound breeding, maximizing the health and well-being of animals destined for essential biomedical research. To avoid a population crash, the number of offspring that can be harvested annually must be based on life table characteristics such as age-specific natality and mortality. We used a modified Leslie matrix to model changes in female population size over 26 years. First, we assumed that all 420 females were released simultaneously and varied the annual birth rate (50%, 60%, 70%), survival rate, and number of offspring harvested per year. Assuming high survival and birth rates vs. low rates, about four times as many female offspring could be harvested annually from a stable population (87 vs. 20 offspring). Terminal population size after 26 years did not differ much across rates modeled (568-696 females). Second, we modeled the number of females actually released (including the recent addition of 42 new female breeders) and harvested (averaging 49 annually 1991-1994), and projected the population through 2014. This indicated that threshold harvest rates and terminal population sizes increased considerably over the first model, assuming intermediate (78 harvested, 952 females) and high (152 harvested, 1,331 females) rates of survivorship and natality, but were unchanged assuming low rates (20 harvested, 559 females). A review of the literature and field observations on Tinjil suggest that actual birth and survival rates resemble the intermediate values modeled. If so, the present density on the island, projected to be ∼215 males and females per square kilometer, is approaching carrying capacity. The high values are realistic upper limits. If actual survivorship and birth rates are at the high end of those modeled, the island's population may be on the verge of rapid expansion, requiring increased harvest and provisioning. © 1996 Wiley-Liss, Inc.

Behavioral responses of longtailed macaques to different cage sizes and common laboratory experiences.

The authors tested the effects of varying cage size on the behavior of 10 female and 10 male Macaca fascicularis by singly caging them for 2 weeks in each of 5 cage sizes, ranging from approximately 20% to 148% of regulation size. Behavior in the regulation cage size, a size 23% smaller, and a size 48% larger did not differ in any analysis. Locomotion was significantly less in the 2 smallest cage sizes. Abnormal behavior occurred only 5% of the time, did not increase as cage size decreased, and did not change significantly over nearly 3 years. Disruption of the normal activity budget in the laboratory environment proved to be a useful indicator of psychological well-being. Moving to a new room and, to a lesser extent, moving into a new, clean cage, regardless of size, was associated with disrupted sleep the 1st night and suppressed activity, especially self-grooming, the next day.

Sex differences in compatibility of pair-housed adult longtailed macaques.

This research was designed to evaluate the effects of same-sex pair housing on the psychological well-being of adult wild-born longtailed macaques (Macaca fascicularis). We studied behavioral compatibility and stress as measured by urinary cortisol excretion in 15 pairs of each sex. Before they were housed together, the pairs were categorized by noncontact pairedpreference testing as preferred, nonpreferred, or randomly assigned partners. Every aspect of data analysis indicated that the success of pairing was strongly related to gender. Whereas 100% of female pairs were compatible, only eight of the 15 male pairs were still together after two weeks, and only five (33%) showed a degree of compatibility resembling that of females. The psychological well-being of virtually all females seemed to be improved during the physical contact paired-housing conditions; they spent more than one-third of the day engaged in social grooming. Paired adult males had much lower interaction rates than adult females. On average, males were initially somewhat stressed by the introduction to a cagemate as indicated by increased urinary cortisol excretion. The noncontact preference testing procedure was no more predictive of pair success than random assignment. For males, the presence of fighting combined with the absence of grooming during the first 90 min opportunity for physical contact ("introduction") was associated with pair incompatibility, but not to a statistically significant extent. For research protocols permitting social grouping of this species, the social contact requirement of the USDA Animal Welfare Rules usually can be met for adult females by pair housing. For males, pairing with other adult males often is unsuccessful; by our estimates, at least 20% of males cannot be pair-housed with other males. These sex differences in response to same-sex adults are consistent with the known socioecology of macaques. Further research is necessary to determine whether adult males have a lower need for social contact than females, or whether their needs are better met by other types of social contact. © 1994 Wiley-Liss, Inc.

Urinary cortisol responses of longtailed macaques to five cage sizes, tethering, sedation, and room change.

Urinary free cortisol responses to five cage sizes, cage level, room change, tethering adaptation, chronic catheterization, and ketamine sedation were measured in 14 female and 14 male wild-born adult Macaca fascicularis. Urinary free cortisol, a physiological measure of psychological well-being that can be collected unobtrusively, provided a measure of the animals' general adrenocortical response to various conditions over a time course of hours. Urinary free cortisol values in response to stimulation with adrenocorticotropic hormone (ACTH) validated the measure as a reflection of blood values. Cortisol values were expressed as a ratio to creatinine, which normalized for differences in urinary output and body weight (muscle mass). Cage size (20-140% of regulation floor area) and housing level (upper vs. lower cage) had no effect on stress, as measured by cortisol excretion. Room change elicited a slight increase in cortisol excretion for the first day, but not to a level suggesting stress. Sedation, surgery, some aspects of tethering adaptation, and chronic catheterization produced urinary cortisol evidence of stress. Even so, animals varied in their responses and all showed adaptation. Males and females did not differ in normal mean values but females tended to have higher cortisol levels in response to potential stressors investigated in this study. Cortisol levels continued to decline gradually throughout the study. © 1993 Wiley-Liss, Inc.