RESUMEN

In this study, we compare the behavioral development of captive male vervet monkeys (Chlorocebus pygerythrus) and Sykes' monkeys (Cercopithecus albogularis) to male hybrids of these species. Focal animal sampling sessions were conducted on the study subjects from birth to 90 months of age. Behavioral categories (affiliative, approach, play, sexual, tension, aggressive) were plotted for each species and the hybrids; curves were fitted using polynomial regression and were evaluated with the Wilcoxon signed ranks test. With the exception of play behaviors, the male C. pygerythrus x C. albogularis hybrids modeled the Sykes' pattern of behavioral development. We suggest that this result reflects a sex-linked paternal effect.

Asunto(s)

Envejecimiento , Conducta Animal , Cercopithecus/genética , Cercopithecus/psicología , Animales , Cruzamientos Genéticos , Masculino , Conducta Social

RESUMEN

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.

RESUMEN

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.

RESUMEN

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.

RESUMEN

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.