Kin recognition by paternal half-siblings in captive Papio cynocephalus.

Our objective in this study was to evaluate whether a group of paternally related, subadult baboons (Papio cynocephalus) would preferentially interact with kin or nonkin when they had been raised apart from kin other than their mothers. Subjects and their mothers were removed from the breeding group and placed in alternate housing within 24 h after birth to ensure that the subjects would not have a social history with either their sire or their half-siblings. At 90 days of age, the 23 subjects were separated from their mothers and assigned to a peer-peer social group. Behavioral performance was measured using focal animal sampling techniques and 12 molecular behavioral criteria. Analyses of the data indicate that in dyadic interactions kin did not interact more frequently than nonkin in performance of affiliative, sociosexual, and agonistic behaviors. The hypothesis that baboons recognize kin in the absence of maternal associations was not supported by the data; moreover, we suggest that social learning and social history are the most likely mechanisms for kin recognition.

Weight growth in savannah baboons: a longitudinal study from birth to adulthood.

Postnatal growth in body weight, from birth to 7 years, was studied longitudinally in a sample of savannah baboons. Measurements of weight were collected on 45 male and 42 female baboons at 12-week intervals. The weights of males and females were treated independently and compared for gender differences. Distance and mean increment curves were used to describe the pattern and changes in the rate of growth. The results demonstrated that the savannah baboon shares a pattern of weight growth similar to that of other anthropoid primates including humans. An adolescent growth spurt was observed for both genders. The intensity of the growth spurt was substantially greater for males. Differential growth rates between genders during adolescence were responsible for the extensive sexual dimorphism exhibited in adult weight. Females were advanced over males in their percentage of adult growth attainment at all ages.

The relation of adiposity and body size to chronological age in olive baboons.

Mixed-longitudinal data on adiposity and body size were taken on 250 male and 452 female olive baboons aged between birth and 8 years. Adiposity was measured as skinfold thickness at the neck, subscapular, suprailiac, and triceps sites; body size measures included weight, crown-rump length, and triceps circumference. Males and females were treated independently and compared for gender differences. Data were tabulated to examine the relation of the somatometric variables to age and the patterns of association among the variables. Females averaged larger skinfold values at all sites for most ages. Males were significantly heavier, longer, and exhibited greater triceps girth at all ages except birth and 1 year where no significant gender difference was found for crown-rump length. In general the three measures of body size were significantly correlated at all ages as were the four measures of adiposity. Significant associations between adiposity and body size measures were not consistent among various ages.

The effects of sexual status on threat, attack and subordinate behaviors of papio monkeys.

Performance of perception of threat, attack, and subordinate behaviors at different phases of the perineal cycle in 24 female group papio monkeys (super-species Papio cynocephalus) was compared. The subjects ranged in age from 36 to 42 months at the inception of the study and were observed over a 2-year period. Females performed significantly fewer threat and attack behaviors during the swollen phase of the perineal cycle and showed no significant differences in the reception of the three behavioral measures. The reduction in the performance of aggression that occurs during the swollen phase of the perineal cycle reflects a shift in the focus of interactions during consortship to a single male.

A vocabulary of abnormal behaviors in restrictively reared chimpanzees.

The purpose of this paper is to establish a vocabulary for the systematic documentation of abnormal behavior in restrictively reared chimpanzees. Such a vocabulary facilitates communication regarding the range of behavior patterns indicative of psychopathology. The behavior of restrictively reared chimpanzees was observed and descriptive terminology is developed to aid in documentation of the range of abnormal behavior observed in restrictively reared chimpanzees. Such documentation is the first step in monitoring and evaluating a rehabilitation program.

Sexual dimorphism in the activity of Olive baboons (Papio cynocephalus anubis) housed in monosexual groups.

In this study, responses to the formation of social groups were compared between adult male and female Papio cynocephalus anubis. Quantitative behavioral data based on systematic focal animal sampling were used to test the hypothesis that adult male and female olive baboons are similar in their behavioral response to (1) the formation of monosexual social groups and (2) the simultaneous reduction of social unit and habitat size. Males and females differed (t test, p less than 0.05) in performance of sexual, tension, and stereotypy behavior during large group formations. During small group formations, males and females differed in play, subordinate, locomotion, manipulation, sexual, tension, and stereotypy behavior. Our observations, clearly indicate that in captivity, under conditions of identical housing, social structure, and social unit history, males and females differ in their behavior performance. Our data suggest that some socioenvironmental conditions, such as the lack of heterosexual grouping, may exaggerate those differences.

Technical note: Urine collection from vervet monkeys by instrumental conditioning.

Gang-caged adult male vervet monkeys were trained to urinate on demand into a plastic beaker by positive reinforcement (peanut rewards). The animals were not separated from their social group during training or sampling.

A model for development of social behavior in vervet monkeys.

Polynomial regression was used to construct linear descriptive models for age-related behavioral changes among socially-living, captive vervet monkeys. Seventeen social acts were divided by gender into performer (director) and recipient to produce 68 predictive equation. The aptness of these models was examined by an analysis of residuals, including a lack-of-fit F test. Consistency was further validated by a sign test comparison of predicted and observed means. A log10 (Y + 1) transformation produced satisfactory fits for 51 of the 68 parameters. Only 1 behavior (male gape D) had a nonsignificant cumulative F value and low coefficient of multiple determination. Although the remaining 16 acts did show age relationships, they exhibited a significant lack of fit to the proposed model. A table of predictive equations is presented as a mathematical model of behavioral development in vervet monkeys.

The structure of social space among a captive group of vervet monkeys.

Proximity data collected during a 34-month longitudinal study of captive vervets are used to generate a quantitative, predictive model consistent with age, gender, kinship, and dominance status variables. Differential ontogenetic patterns of uterine and non-uterine passive contact and nearness are described for males and females, illustrating decreased distance with age in females and increased disperson for males. Proximal relationships are structured by kinship, although not uniformly across genders and age ranges. Higher-ranking kin-groups appear more cohesive, based on uterine contact and nearness, while non-uterine proximity is not significantly differentiated on the basis of matrilineal dominance.

Is the concept of "control group" valid? A quantitative comparison of behavior of caged baboon groups.

Behavioral comparisons between six caged baboon groups indicate that the groups have consistent and similar behavioral attributes. At the same time it is possible to distinguish between classes of animals in each group such as males versus females and high status versus low status rank. Comparable results are obtained in both ANOVA and Kruskal-Wallis one-way analysis of variance by ranks. This investigation supports the assumption that baboon groups exhibit behaviors that are both consistent and predictable where environment and group composition are controlled. Thus there appears to be a strong species-appropriate set of behaviors. Behavioral plasticity and group variability might be due largely to a combination of environmental stimuli and the particular history of that group. Differential individual histories or idiosyncracies do not invalidate experimental designs which rely on randomization to structure control groups.

Gender and environment as determinants of behavior in infant common baboons (Papio cynocephalus).

Two groups of infant baboons were observed. The breast-fed group was housed in a gang cage with nursing mothers (n = 13) and the other motherless group was in a wire-cage nursery habitat (n = 20). Differences in behavior due to gender and environment were tested by analysis of variance. The results do not support the hypothesis that innate sex differences exist in baboons aged 0-3 months. Nursery-reared subjects had significantly higher scores for rough-and-tumble play, stereotypy, threat, avoid, explore, high tension, and nonaggressive social behaviors, but these behaviors are not significantly different between sexes in either groups.

Social organization and food resources availability in primates: a socio-bioenergetic analysis of diet and disease hypotheses.

Data obtained during a field study of two species of nonhuman primates (Alouatta villosa and Ateles geoffroyi) living in the Tikal National Park in Guatemala are used to suggest an answer to the question: To what extent is the existence of a particular form of social organization (group size, structure, and composition) an indication of the amount of energy in the form of food resources available to animals in a particular habitat? Seven researchers working in teams spent 2,318 hours in the field, 1,145 hours of which were in contact with the monkeys. Comparisons of dietary data, estimated energy expenditures, and habitat productivity provide indications of the degree to which a habitat is capable of supporting the energy and other nutritional requirements of howler and spider monkeys living within the study area. These data suggest that much larger populations and different forms of social organizations can be supported by resources available within the habitat.