Banding patterns of the chromosomes ofCercopithecus neglectus: Comparison withMiopithecus talapoin andErythrocebus patas

The G, Q, and C bands and the location of the nucleolar organizing regions (NORs) of the chromosomes of two male Cercopithecus neglectusare described. The diploid number of the species is 2n =62. Comparison with the karyotypes of Miopithecus talapoin (2n =54), and Erythrocebus patas (2n =54)showed the presence of total banding homeology for only 10 chromosome pairs.     

The ontogeny of sex differences in the behavior of patas monkeys

Many studies of sex differences in primates have been based on small experimental groups of peers in which only a limited range of social behavior could be expressed. In addition, the first few months of life are often the focus of such studies, with relatively little attention paid to older juveniles. In this study, 11 male and 9 female juvenile patas monkeys, living in a captive social group with all age-sex classes available, were observed between 1 and 4 years of age. A subset of seven patas monkeys was also observed between birth and 1 year of age. Here, we report the development of sex differences in independence, play, grooming, positioning behavior, and aggression over the juvenile period. Juvenile male patas monkeys played more and in longer bouts than females, but wrestling (rough-and-tumble play) was not more common among males. There were few differences in behaviors directed to male and female juveniles by other group members. Distinct differences emerged only in the behaviors of the juveniles themselves, with females being more active participants in social and aggressive interactions than males. In general, sex differences in patas monkeys show a mixture of patterns, some of which are predictive of adult sex differences and some of which appear to be specific to the particular demands of the juvenile period in this species     

Intimate social behavior in infant interactions in Cebus apella

The development and individual stability of three intimate social behaviors (Lipsmacking, Carrying Attempts, and Facial Inspection) were examined for 43 group-housed Cebus apella infants from birth to 2 years of age. Occurrence of these behaviors was scored from 10-min videotape samples recorded three times a week over that time. Frequency of Lipsmacking and Carrying Attempts by adult males, adult females, and juveniles were all highest in early months and decreased to low levels by the end of the first year. Facial Inspection of partners by infants, in contrast, first began at 3-4 months and increased over time, at least to adult males and juveniles. Correlational analyses indicated stable individual differences in these interactions with infants and outlined a relationship between these intimate behaviors and more general social patterns reported previously for these animals. Results suggest that adult males may play a special role in affording juveniles opportunities for social learning of foraging and manipulative skills.     

Allomaternal behavior in a group of free-ranging patas monkeys

A free-ranging group of patas monkeys (Erythrocebus patas) containing 18 individually identifiable adult females was observed for approximately 400 hours, equally distributed over two two-month periods corresponding to the breeding and birth seasons, at the La Parguera facility of the Caribbean Primate Research Center. The large number of infants born in the spring and early summer (n = 14) allowed for detailed observations of alloparental behaviors, with a focus on allomothering by the adult females. Seven types of alloparental behaviors were recorded: contact, nuzzling, grooming, agonism, close visual inspection, attempted kidnapping, and kidnapping. Adult females emitted the vast majority of allomaternal behavior, the patterning and frequency of which closely resembled the patterning and frequency of inter-adult female social grooming. Relative dominance status of the participants did not consistently predict the directionality of allomothering. The most commonly observed allomaternal behaviors were contact and nuzzling, which are primarily affiliative behaviors; agonism was rare. Successful kidnapping occurred eight times. Immature monkeys (n = 22) emitted an additional 32 alloparental acts. A propensity towards allomothering by experienced females would be most beneficial to patas infants due to the patas' tendency towards dispersed foraging and rapid flight in the presence of danger. It is possible that direct competition with groups of rhesus macaques for available resources on the island served as a proximal cause for the allomothering observed in this patas group.     

The effects of prenatal PCBs on adult social behavior in rats

Endocrine disrupting chemical (EDC) exposures during critical periods of development may influence neuronal development and the manifestation of sexually dimorphic sociability and social novelty behaviors in adulthood. In this study, we assessed the effects of gestational exposure to PCBs on the social behavior of males and females later in adulthood. A weakly estrogenic PCB mixture, Aroclor 1221 (A1221, 0.5 or 1 mg/kg) was administered to pregnant Sprague–Dawley rat dams. Both a positive control (estradiol benzoate; EB, 50 μg/kg) and negative control (dimethylsulfoxide; DMSO in sesame oil vehicle) were similarly administered to separate sets of dams. The sexes responded differently in two tasks essential to sociality. Using a three-chamber apparatus that contained a caged, same-sex, gonadectomized stimulus animal and an empty stimulus cage, we found that both sexes showed a strong preference for affiliating with a stimulus animal (vs. an empty cage), an effect that was much more pronounced in the males. In the second task, a novel and a familiar stimulus animal were caged at opposite ends of the same apparatus. Females displayed a higher degree of novelty preference than the males. During both tests, females had significantly higher social approach behaviors while male engaged in significantly more interactive behaviors with the conspecific. Of particular interest, males born of dams that received prenatal A1221 (0.5 mg/kg) exhibited an overall decrease in nose-to-nose investigations. These behavioral data suggest that the males are more sensitive to A1221 treatment than are females. In addition to behavioral analysis, serum corticosterone was measured. Females born of dams treated with A1221 (0.5 mg/kg) had significantly higher concentrations of corticosterone than the DMSO female group; males were unaffected. Females also had significantly higher corticosterone concentrations than did males. Overall, our results suggest that the effects of gestational exposure to PCBs on adult social behavior are relatively limited within this particular paradigm.     

卡麦角林对雄性黄毛鼠社会行为的影响

不育控制既可直接降低害鼠种群的生育率,又能影响个体的社会行为,引起种群内等级关系和社群结构的变化,进而干扰种群繁殖。为探究不同剂量卡麦角林对雄鼠行为的影响和持效时间,选取健康雄性黄毛鼠使用50mg/kg和100 mg/kg卡麦角林灌胃给药,并于给药后第1 d和第18 d与正常雄鼠遭遇,第4 d和第21 d与正常雌鼠遭遇,比较给药前（卡麦角林灌胃前4 d和前1 d 时分别与正常雄鼠和雌鼠遭遇）和给药后个体行为的差异。结果显示：卡麦角林降低了雄鼠对正常雄鼠的探究、攻击时间,降低雄鼠对正常雌鼠的攻击时间和频次;100 μg/kg卡麦角林降低雄鼠对正常雌鼠的探究频次,且雄鼠自身修饰和休息频次显著减少。这表明卡麦角林可干扰黄毛鼠对同性和异性个体间的社会行为。此外,药物处理后第18 d和第21 d,雄性个体与同性和异性个体的社会行为与处理前无显著差异,表明停药后药物对行为的影响会随着时间的延长逐渐消失。       

The social behavior of a marmoset (Saguinus fuscicollis) group II: Behavior patterns and social interaction

The behavioral patterns and social interaction of a marmoset (Saguinus fuscicollis) group in a semi-naturalistic environment were observed for 14 months. The analysis showed that, of the 32 behavior patterns observed, the 10 most frequent accounted for over 97 per cent of the total behavior. One pattern, sit and look, accounted for 44 per cent of the total behavior. The two most frequent social behavior patterns, grooming and social play, were concentrated in different parts of the group. The focal point of grooming was the adult female; social play was characteristic of younger animals 4–20 months of age. These results were compared with other studies of marmosets and with primate studies on grooming and social play.     

The effects of fur rubbing on the social behavior of tufted capuchin monkeys

Fur rubbing has often been attributed as a social as well as a medicinal function in capuchin monkeys, yet to date there have been no studies investigating the effects of fur rubbing on subsequent group dynamics. Here, we report for the first time how social group cohesion is affected by fur rubbing in tufted capuchin monkeys. Fifteen captive capuchins were each observed six times for 45 min, three times following the provision of materials typically used for fur rubbing (onion) and three times following control food items (apple). When compared with the apple condition, monkeys significantly increased proximity to one another in the first 15 min of the onion condition, which is when most fur rubbing took place. Moreover, monkeys were more likely to spend time in groups when fur rubbing but less likely to spend time in groups when manipulating the onion in other ways. In subsequent periods monkeys were less likely to be in proximity to one another in the onion condition compared with the apple condition. Aggression between group members was elevated whereas affiliation was decreased throughout the onion condition. In short, capuchins spent more time further apart and engaged in more aggressive acts and shorter affiliative acts following fur-rubbing bouts. It is possible that these differences in behavior could be owing to differences in how the monkeys competed for and interacted with the items presented in each condition rather than due to fur rubbing as such. Alternatively, fur rubbing with pungent materials might interfere with olfactory cues used to regulate social interactions within a group and thereby cause increased levels of aggression.     

Aggregation in woodlice: social interaction and density effects

Terrestrial isopods are known to be sensitive to humidity, brightness or temperature. Until now, aggregation was assumed to depend on these sensitivities as a result of individual preferences. In this paper, we show that the social component is also important in the isopod aggregation phenomenon. In experimental arenas with two identical shelters up to nearly 90% of woodlice aggregated under shelters. This aggregation was quick as in 10 minutes most of the animals aggregated, irrespective of their density. Nonetheless, 10-15% of the animals walked around the arena, rarely forming very small and short-lasting aggregates outside shelters. Woodlice aggregated preferably under one of the shelters in 77% of experiments. Indeed, almost 80% of the animals out of 40, 60 or 80 animals in the arena aggregated under one shelter. In arenas with 100 individuals the aggregations were proportionally smaller (70%). Our results revealed that 70 animals was a maximum number of woodlice in an aggregate. We concluded that the location of aggregates is strongly governed by individual preferences but the dynamics of aggregation and collective choice are controlled by social interaction between congeners. The tested densities of the animals in the arena did not impact the aggregation patterns.     

The influence of anaesthetics on the haematology of the patas monkey, Erythrocebus patas.

The effects of phencyclidine, ketamine and an alphaxalone-alphadolone mixture on the haematology of the patas monkeys have been compared. In animals sedated with phencyclidine or ketamine the only significant difference detected was in the mean cell volume. Statistically significant differences in white-cell count and blood coagulation and fibrinolytic activity were found in monkeys which had received alphaxalone-alphadolone. It is suggested that ketamine is a suitable alternative to phencyclidine for haematological studies in these monkeys.     

The ecology of the introduced patas monkey (Erythrocebus patas) population of Southwestern Puerto Rico

This paper presents the results of a study on the introduced, free-ranging patas monkey population of Southwestern Puerto Rico (SWPR). It describes information on the population size, social group composition, diet, daily ranging patterns, and patas home range during a 3 year period. The patas monkey population in the study area consisted of approximately 120 individuals in four heterosexual groups and several all-male bands. Within their home ranges (26.8 km²), the population density was 4.47 individuals/km². Home range size among the population's four heterosexual groups varied from 3.72 km² to 15.39 km², and minimum daily distance traveled ranged from 0.8–2.0 km. In general, the social structure and mating system of this population parallels what has been described for African populations. However, habitat use, ranging behavior, and the quality of intergroup interactions suggests that patas of this population exhibit territorial behavior. Am. J. Primatol. 45:351–365, 1998. © 1998 Wiley-Liss, Inc.     

The effects of undernutrition upon the energy reserve of the brain and upon other selected metabolic intermediates in brains and livers of infant rats

—Rats undernourished from the first to the ninth day of life exhibited no decrease in the energy reserve (P-creatine, ATP, glucose and glycogen) of the brain, although they underwent a 41 per cent decrease in body weight. The apparent increase in the cerebral levels of glucose-6-phosphate and the decreases in hepatic glucose and lactate in the starved animals were probably a consequence of the fact that they froze faster than the control animals rather than of any essential differences in vivo. However, decreases in cerebral glutamate (11 per cent) and hepatic glutamate (33 per cent) in the undernourished animals cannot be explained on this basis. Possible explanations for this decrease in cerebral glutamate content are: a decreased supply of glutamate from the liver, a decreased synthesis of glutamate by the brain, or an increased use of glutamate as an energy source. Since levels of glutamate in the brain increase progressively during the first weeks of life, another interesting possibility is that the lower level of cerebral glutamate in undernourished rats represents a biochemical indicator of a delay in the maturation of specific morphological components which are rich in glutamate and are characteristic of the brain.     

The effects of extended exposure to traffic noise on parid social and risk-taking behavior

Traffic noise is a prevalent and yet poorly understood anthropogenic disturbance associated with reduced avian diversity, population densities and pairing and mating success. How these systems are affected is not clear as a direct experimental link between noise and behavior underlying these patterns is missing. Here we provide the first empirical evidence of the effects of long-term exposure to simulated traffic noise on social and risk-taking behavior of Carolina chickadees (Poecile carolinensis) and tufted titmice (Baeolophus bicolor). In testing for these effects we compare two hypotheses regarding the effects of noise on behavior. We found that noise increases sociality by reducing nearest neighbor distances and increasing the number of close-perches within study flocks. These behavioral responses mimic those of species in high-risk situations, such as birds in the presence of a predator. These results provide support for the 'Increased Threat Hypothesis,' which argues that chronic traffic noise affects behavior by increasing the perceived level of threat. Although the adaptive value or function of these responses to noise is unknown, they may serve to mitigate any negative effects of traffic noise. If true, species lacking behavioral plasticity may be more susceptible to effects of traffic noise and other similar acoustic disturbances.     

Effects of social isolation and crowding upon adrenocortical reactivity and behavior in the rat

The effects of social isolation and crowding on adrenocortical function and upon behavioral responsiveness to electric shock have been studied in male and female rats. All female experimental groups showed higher corticosterone levels and heavier adrenals than their male counterparts. The major effect of housing condition concerned the corticosterone response to stress, while basal hormone concentration was not modified. Socially housed rats showed a more intense adrenocortical response and also a greater behavioral reactivity to electric shock than the isolates.