Conditioned exercise method for use with nonhuman primates.

The objective of this study was to demonstrate the feasibility of using appetitive methods to train adult male olive baboons (Papio cynocephalus anubis), who were socially housed and fitted with indwelling catheter/ transducer systems, to exercise on an inclined, motorized, moving treadmill. All subjects were first trained to walk on a motorized treadmill for 30 min at a speed of approximately 1.6 km/hr on a 0 grade. Upon completion of initial exercise training, six animals were assigned to a low exercise group (LOW), six were assigned to a moderate exercise group (MOD), and six were assigned to a sedentary control group (SED). The LOW group exercised 30 min per day on an elevated treadmill, the MOD group exercised 60 min per day on an elevated treadmill and the SED group did not perform any treadmill exercise. The 12 animals comprising the LOW and MOD groups were exercised 4 days per week and their performance was increased over a subsequent 30-week experimental period. We gradually increased speed and grade demands over several weeks and produced an animal model capable of traveling at speeds up to 5.5 km/hr on a 22% grade and distances up to 3,353 m horizontally and 549 m vertically in a 1-hr session. © 1992 Wiley-Liss, Inc.

Assessing the effects of social environment on blood pressure and heart rates of baboons.

The objective of this publication is to report on the feasibility of using a tether system for obtaining data on blood pressure and heart rates of socially housed primates and to evaluate the extent to which housing environment alters cardiovascular responses (mean arterial blood pressure and heart rate). Blood pressure and heart rates of adult male baboons (Papio cynocephalus hamadryas) were evaluated over a 6 week period under three different housing conditions: social companion, individual, and socially unfamiliar. Social environment was manipulated in a specially designed cage that incorporated removable panels of either woven wire or solid sheet metal. The design of the cage permitted nonhuman primates to engage in species-typical social behaviors such as grooming and aggression. Using a tether and catheter system, we monitored cardiovascular physiology. We tested the hypothesis that individual housing, housing with social companions, and housing with social strangers would produce different mean arterial blood pressure and heart rate responses. Individual housing and housing with strangers produced resting mean arterial blood pressures that were elevated relative to blood pressure responses with social companions. Individual housing and housing with social strangers produced different patterns of cardiovascular response. Individual housing resulted in lowered heart rates and elevated blood pressures relative to the social companion condition. Housing with social strangers resulted in both elevated blood pressure and elevated heart rate, relative to the social companion condition. Responses observed during this study demonstrated the sensitivity of blood pressure and heart rates to differences in social environment.

Neonatal nutrition and longitudinal growth in baboons: Adiposity measured by skinfold thickness.

This paper reports the results of a 5 year longitudinal experiment that (1) examined growth in adiposity of a group of 48 clinically normal olive savannah baboons (Papio cynocephalus anubis) who were randomly assigned at birth to one of three diet treatments that differed, during the first 16 weeks, in the amount of nutrients they provided; (2) tested the hypothesis that different amounts of food availability during the neonatal period (birth to 16 weeks) had a significant effect on growth and development of adiposity in the subsequent infant, juvenile, and adolescent periods; and (3) evaluated the extent to which underfed (LC) and overfed (HC) subjects were capable of growth canalization. Each diet contained different caloric densities but the same proportion of fat (34%), carbohydrate (55%), and protein (11%). All animals were fed the same volume of formula; however, HC subject were fed 40% more calories than MC subjects, who were fed 40% more calories than the LC subjects. Growth and development of adiposity were assessed by measuring neck, triceps, subscapular, and suprailiac skinfolds weekly from birth to 16 weeks and at 13 week intervals from 26 to 260 weeks of age. We found that during the first 16 weeks of the experiments, baboon growth was strongly influenced by food shortages but not by excesses; however, when the dietary treatment ceased, growth appeared to be strongly regulated by a genetic component (developmental canalization) and tended to return to a more normal growth pattern within a 26 week time frame. Males and females exhibited differences in adipose development in that males did not exhibit residual treatment effects while females tended to retain the effects of neonatal dietary treatments through early adolescence.

Formula-fed and breast-fed baboons: Weight growth from birth to adulthood.

The objective of this study was to compare the immediate and long-term effects of type of infant diet (formula-fed vs. breast-fed) on the weight growth of baboons. Longitudinal (serial) weight data were collected from 44 savannah baboons (Papio cynocephalus anubis) for the total preadult period of growth from birth to approximately 8 years of age. Fifty percent of the sample (11 females and 11 males) were fed a standard infant formula by a nursery care technician for the first 18 weeks of postnatal life. The remaining 11 females and 11 males were breast-fed by their mothers for an equivalent period of time. After 18 weeks of age the animals were removed from their infant environments (either nursery or mother-reared) and assigned to one of four age-cohort social groups. Each age-cohort group was balanced for infant treatment and gender. The animals remained in these social groups for the duration of the project and were provided nutritionally identical postweaning diets. No significant weight differences were found between the two rearing conditions for either gender during the initial 15 weeks of growth. Following this period, however, females of breast-fed environments averaged greater weight at all ages than their bottle-fed peers. The intensity of the adolescent growth spurt was also slightly greater among the female breast-fed group. No postinfant average weight-per-age disparity was observed between the male treatment groups.

Scratching, dominance, tension, and displacement in male baboons.

This paper reports a study designed to test the hypothesis that a relationship exists among dominance rank, tension, and scratch behaviors in anubis baboons (Papio cynocephalus anubis). Our study was conducted on two groups of male baboons, each containing eight unrelated individuals who were approximately 6 years of age and who shared common rearing histories. Focal animal sampling was used to collect behavioral data. Hand scratching, foot scratching, avoid, tension, allogrooming, autogrooming, and manipulation were measured as acts performed per hour of sampling. Dominance matrices were constructed based on net difference of avoid behavior performed and received (adjusted for time sampled). Individual status ranks were grouped into two status classes, high and low. Analysis of variance models demonstrated significant differences in the performance rate of scratching behaviors by dominance rank class, as well as differences in scratching performance by tension class. Individuals in the high status class had significantly higher rates of total scratching, hand scratching, foot scratching, and tension behavior performance than their counterparts in the low status class. No significant difference was found between status classes or tension classes for performance rate of allogrooming, autogrooming, or manipulation behavior. The frequency of scratching and general level of activity were not significantly correlated. The results are interpreted to indicate the possibility that scratching may function as a displacement behavior, which subjectively appears to communicate heightened frustration, anxiety, or arousal.

Body composition in baboons: Evaluating a morphometric method.

The objective of this study was to determine whether noninvasive morphometric measurements of olive baboons (Papio cynocephalus anubis) can reliably predict lean body mass and fat mass in this species. Crown-rump length, triceps circumference, and skinfold measures at the neck, subscapular, suprailiac, and triceps sites were obtained prior to necropsy from 21 clinically normal infant baboons at 18 weeks of age and from 22 clinically normal adolescent baboons at 5 years of age. At necropsy, the lean body mass and body fat mass were measured using gravimetric methods. Pearson's correlations and regression analysis were used to test the relationship between direct measures of lean and fat mass obtained at necropsy with calculated estimates based on morphometric measures obtained prior to death. Our null hypothesis was that the morphometric measures (individually or in combination) were not related to direct measures of fat mass or lean mass. Non-linear and multiple regression estimators, by age and gender, were derived and provided increased predictability. Our results indicate that (1) morphometric measures can accurately predict lean body mass in male and female baboons; (2) morphometric measures used to predict lean body mass change with age; (3) morphometric measures are strongly associated with body fat mass at 18 weeks of age but are not as strongly associated with body fat mass in 5-year-old baboons; (4) triceps circumference provides the best single indicator of lean body mass for both genders and age periods; (5) baboons are like humans in that adolescent females tend to accumulate body fat while males of the same age tend to develop lean mass; and (6) combinations of these morphometric measurements explain between 70% and 100% of the variability and can be used to estimate lean and fat mass in baboons.

Age changes in affinitive behaviors of baboons.

The behavioral development of 96 baboons was systematically recorded from birth to 84 months of age. Eight behaviors were selected as criteria for examining the effects of early rearing experiences (mother-peer vs peer-peer), gender, age, and cohort as possible sources of variance in the development of affinitive behaviors of this species. Stepwise multiple regression was used to analyze the data and provide quantitative descriptions of the relationships between the selected independent variables and the rates of social behavior during maturation. Among the behaviors studied, three types of developmental patterns were identified. Embrace and groom shared the first developmental pattern; muzzle-body and muzzle-muzzle, the second; and contact, hold, huddle, touch, the third. Gender differences were evident in only the first behavior pattern group. Age was a strong predictor of behavioral performance rate in all but huddle. Cohort, or the combined effects of age, body size, and temporal peer grouping, was an important predictive factor in all but contact and muzzle-muzzle behavior. Early rearing experiences did not produce any significant differences in performance of the affinitive behaviors studied. It is suggested that genetic control of maturation shapes the development of these behaviors in baboons, regardless of subtle environmental experiences.

Social play in differentially reared infant and juvenile baboons (Papio sp).

Effects of early experience and peer-group socialization on later play behavior of baboons (Papio sp) was assessed. The potential for development of sex differences in play behavior in the absence of sex-role models was of particular concern. Social play of nursery-reared baboons was contrasted with that of mother-reared conspecifics during late infancy (6-12 mo) and the late-juvenile period (36-42 mo). Males played more than did females and infants played more than did juveniles. There was no significant influence of early rearing conditions on play behavior despite effects on other behaviors. There were consistent sex differences in play behavior even for the individuals with no early access to sex-role models. This result is consistent with previous research indicating a strong hormonal basis of sex-differences in primate play behavior.

Age estimation from dental eruption in infant and juvenile baboons (Papio sp.).

Two regression methods are proposed for estimating age in nonhuman primates from deciduous dental eruption data. The first method consists of step-wise multiple regression using dental eruption state (present/absent) of each tooth as independent variables. The second method uses the total number of teeth erupted as an independent variable in an exponential model. We applied both methods to a sample of 175 well nourished infant and juvenile baboons (Papio sp.), housed in an outdoor breeding corral, and ranging in age from birth to 763 days. From this sample, 129 animals were used to compute the regression formulae, and 46 animals were used for cross validation. Both models show good overall fits and high predictive accuracy with the independent cross validation sample.

Sequence and age of eruption of deciduous dentition in the baboon (Papio sp).

A detailed eruption sequence and associated age of eruption for deciduous dentition in baboons (Papio sp) are presented in this paper. The sequence was determined by evaluation and comparison of the number and kinds of teeth present in nine age cohorts comprising the study sample of 88 males and 87 females who ranged in age from birth to 763 days. Eruption was assessed visually as present or absent. Several statistical methods used to derive the ages associated with the eruption sequence are described. The basic eruption sequence in the sample population is: i1 i1 , i2 , i2 , \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm c}\limits_{\rm -} {\rm,}\mathop {\rm c}\limits^{\rm -} $\end{document} m1 (m2 , m2 ), M1 , M1 . Both sexes show the same pattern, with the exception of the second deciduous molar, where males show a sequence of m2 , m2 , while females show the opposite. Posterior dentition shows the greatest gender-specific variation in average age of eruption.

Longitudinal stability in adult status hierarchies among vervet monkeys (Cercopithecus aethiops).

Status hierarchies were examined in a captive group over a 12-year period (1968-1979) to establish the stability and structure of vervet monkey dominance relationships. Dyadic records of spontaneous avoid, bite, chase, and supplant behaviors are summarized into a win/lose matrix to produce a rank order of status at the end of each calendar year. The 13,717 agonistic acts tabulated are drawn from both focal and ad lib data. Relative rank is computed by dividing the rank position of each individual by the number of individuals ranked for that year. Relative rank was found to be quite stable for adults of both sexes, although males were more variable than females. There was a strong matinrline effect on all captive born animals' rank position. No gender difference in rank was demonstrable. Infants were very subordinate at the end of their first year, but rose to positions near those of their mothers by the end of the fourth year. Presence or absence of canine teeth had no demonstrable effect on status. The results emphasize the relative importance of social learning in the establishment and maintenance of dominance relationships. The apparent gender difference in rank among wild living vervets is hypothesized to be a consequence of the male intergroup mobility. If a male is restrained from emigration, he is strongly affected by his mother's rank as he establishes his own dominance position in the troop.

Effects of rearing on aggression and subordination in papio monkeys.

The objective of this study is to assess the effects of short-term maternal deprivation (birth to 12 weeks) followed by peer group rearing on the development of aggressive and subordinate behaviors in papio monkeys (superspecies - Papio cynocephalus). Nursery reared monkeys (34 males and 30 females) were compared with mother-peer reared monkeys (11 males and 12 females) in late infancy (6 to 12 months of age) and at the end of their juvenile stage (36 to 42 months of age) in social groups composed of 75% nursery reared subjects and 25% mother reared subjects. Focal animal data were analyzed with a repeated measure ANOVA model. In general, the nursery reared infants tended to be less aggressive than mother-peer reared infants and performed less dominance behaviors, such as displace. Significant sex differences were present in the performance of aggressive (♂ > ♀) and subordinate (♂ > ♀) behaviors. Significant age differences were observed, with infants having consistently higher rates of performance.