Reciprocity and partner preference in grooming of female blue monkeys

Grooming among adult and older juvenile females in a wild group of blue monkeys (Cercopithecus mitis stuhlmanni) is analyzed and related to agonistic behavior. Both grooming and agonistic behavior were less frequent than would be expected in baboon and macaque groups. Fair shares of grooming were given and taken, both within and between interactions, in amost dyads, and all females were seen to groom with at least half the others. The reciprovity of grooming was its most outstanding feature. There was no evidence that grooming was preferentially directed at kin. Frequent grooming partnerships fell into two clusters, one of which ranked higher than the other. We suggest that grooming throughout the group helps to establish a coherent team of females which effectively, defends its territory in daily encounters at the boundaries with neighboring groups.     

Influence of kinship and spatial density on reconciliation and grooming in rhesus monkeys

Some cercopithecine primates direct disproportionate amounts of grooming, huddling, and agonistic support toward maternal kin. Disproportionate amounts of aggression are also directed toward maternal kin, however, suggesting that mechanisms that restore relationships damaged by aggression, such as reconciliation, might be biased toward these preferred social partners. Studies investigating kinship effects and reconciliation are inconsistent, however, perhaps because of differences in the environmental conditions under which behavior was observed. In order to test the effects of kinship and spatial density on affiliative and reconciliation behavior, we conducted focal and scan sampling on a group of rhesus monkeys (Macaca mulatta) living in an outdoor corral under low spatial density conditions. We then compared this data to previously published data on a group of the same species living under higher spatial density conditions. Neither overall grooming nor reconciliation were affected by spatial density once correction procedures were applied. Grooming was kin biased at both study sites, whereas reconciliation was kin biased only in the low-density group. Although data failed to support a Coping Model according to which grooming and reconciliation should go up under higher densities, we suggest that coping may be reflected not so much in overall rates of behavior but in strategic partner choices, such as the increased importance monkeys under crowded conditions appear to attach to nonkin partners. © 1996 Wiley-Liss, Inc.     

Self-agency in rhesus monkeys

Rhesus monkeys (Macaca mulatta) have shown the ability to monitor their own mental states, but fail the mirror self-recognition test. In humans, the sense of self-agency is closely related to self-awareness, and results from monitoring the relationship between intentional, sensorimotor and perceptual information. Humans and rhesus monkeys were trained to move a computer icon with a joystick while a distractor icon partially matched their movements. Both humans and monkeys were able to monitor and identify the icon they were controlling, suggesting they have some understanding of self-agency.     

Early agonistic experience and rank acquisition among free-ranging infant rhesus monkeys

Several aspects of agonistic experience are described for freeranging infant rhesus monkeys (Macaca mulatta)on Cayo Santiago. Even before infants are fully integrated with peers in rank dominance based on maternal ranks,infants of highranking mothers tend to be threatened less frequently by other members of the group and are less likely to be threatened by unfamiliar individuals than are infants of lowranking mothers. There is no evidence that fearful interactions between pairs of infants are related to their mother’s ranks before 22 weeks of age. However, an imperfect hierarchy can be constructed for infants between 27 and 30 weeks of age. At this age,infants of higherranking mothers are also more likely to receive protection when threatened than are infants of lowerranking mothers. When protected, their protectors are less likely to emit fearful gestures to the infants’ threatener. Close female relatives appear to play a large role in the protection of infants and may be more directly responsible for the differences described above than the mother, other relatives, or other highranking members of the group. It is suggested that more than one mechanism, including intervention by the mother and by close female relatives,may be important in rank acquisition among peers.     

Breeding-season relationships of immature male rhesus monkeys with females. I. Individual differences and constraints on partner choice

Several aspects of breeding-season relationships with mature females are described for free-ranging immature male rhesus monkeys (Macaca mulatta)on Cayo Santiago. At puberty, immature males are still groomed by mature females, as they were as infants, but no longer receive active protection from females other than their mothers. A further, potentially beneficial, aspect of their associations with females lies in the opportunities to observe closely the tactical social and sexual interactions of receptive females with adult males. However, immature males themselves rarely copulate with females. Developmental constraints may explain the finding that most females observed by immature males were relatives but that high-ranking males showed a particular preference for adolescent relatives, whereas the preference of low-ranking males was for adult relatives. A further finding was that while there was a tendency for immature males to devote a greater proportion of their total observation time to females that ranked above their mothers than to those of inferior rank, these were also the females from which males received the most aggression, while most of the females with which the males groomed or copulated were lower ranking than the males’ mothers. Of three hypotheses concerning three possible types of social constraint which might account for such a finding, the data supported only one—that particular levels of aggression within these relationships are compatible only with certain other elements (observations), and not with others (grooming, copulation).     

The social grooming of captive female rhesus monkeys: Effects of the births of their infants

We observed the grooming interactions of 13 female rhesus monkeys (Macaca mulatta)before and for 12 weeks after the births of their infants. Mothers groomed for similar amounts of time before and after the birth of their infants, but after the birth, the grooming they directed to their infants may have been at the expense of that directed to other partners. Lactating females did not receive more grooming from other females but were approached more often, suggesting that they were more attractive. Mothers that groomed their infants most groomed others least, as if grooming time was limited for each mother or as if she was trying to compensate for avoiding interactions with other partners. Mothers of male infants groomed others more than mothers with female infants did, which might be due to mothers with daughters receiving more aggression and therefore avoiding interaction. Experienced and high-ranking mothers groomed their newborn infants considerably more than primiparous mothers did in the 24 hr following birth. Grooming was preferentially directed at close kin before the births of the infants. Mothers tended to groom higher-ranked partners more than they were groomed by them, and they tended to receive more grooming from lower-ranked partners than they gave, as suggested in models of rank attractiveness.     

Extinction of rhesus monkeys (Macaca mulatto) in Xinglung,North China

An isolated population of rhesus monkeys living in Xinglung County, north of Beijing (latitude 40⪤gree N), was a natural population at the northernmost range of the species in Asia. Rhesus had been reported there at the end of the last century, based on a few specimens, but were not well known by zoologists until the beginning of the 1960s. The population remained approximately 50–60 individuals in the 1960s but then declined to only 4 or 5 monkeys about 5 years ago. It has been confirmed by local hunters and two recent field trips that the population is now probably extinct. As a result, the northern extent of the remaining natural range of the rhesus macaque in Asia has dropped 650 km southward to the Jiyuan Nature Reserve on the border of Hunan and Shanxi provinces, just north of the Yellow River.     

A microagglutination test for blood typing rhesus monkeys, Macaca mulatta

Summary. We have developed a microagglutination test for typing rhesus monkey erythrocytes that is sensitive, accurate and easy to perform. The technique requires only μ1 quantities of antiserum and cells, and agglutination is easily detected using an inverted microscope. An advantage of this technique is that the typing plates can be stored at -70°C without loss of activity. The results of typing over 400 rhesus blood samples with this technique were 95% concordant with results using the standard microtitre agglutination technique. Preliminary results indicate that this test is also adaptable to typing human blood.     

The influence of behavioral context and social characteristics on the physical aspects of social grooming in rhesus monkeys

The extent to which dominance status and sex can influence the physical act of grooming was examined in two groups of rhesus monkeys. Both the sex and the dominance status of the groomee, but not of the groomer, were found to affect the body sites groomed and the positions assumed by the animals during the grooming bout. Females were groomed more on the back and head and less on the tail, rump, upper leg, and lower arm than males. Females with infants tended to face away from the groomer. Higher-ranking groomees were groomed more on the tail and rump and less on the upper leg and back than lower-ranking groomees. Higher-ranking groomees spent more time lying down during grooming than lower-ranking groomees, while lower-ranking groomees faced away from the groomer more then higher-ranking groomees. The behavioral interactions just prior to and immediately after grooming were also recorded. Although the onset of grooming was preceded by social interactions between the partners, the end of grooming was followed by a complete break in interactions. Particular types of social signals displayed by the groomee just prior to grooming were highly correlated with the grooming of specific body sites. These results suggest that the groomee controls the behavior of the groomer by the social signals it displays and the positions it maintains during the grooming bout. Thus, the grooming act itself may play an important role in the social relationships between group members.     

Infant-directed behavior in young rhesus monkeys: Sex differences and effects of prenatal androgens

Young (3–4 years old) laboratory-reared rhesus monkeys were observed in five 15-minute tests with 1–15-day-old infants. Males and females were equally likely to investigate infants. Females communicated more with infants by grin-lipsmacking and gurgling–-gestures that were not shown by any males. More females presented the ventrum to infants than did males. Females contacted infants more than did males by grooming, crouching over, and having full body contact with them. To see whether prenatal androgens produced the male pattern of response, we conducted similar tests with pseudohermaphrodites (prenatally androgenized genetic females) and neonatally castrated males. On most sexually dimorphic behaviors, pseudohermaphrodites behaved more like females than like males. Castrated males, like females and pseudohermaphrodites, crouched over infants more than did intact males. Castrated males differed from females only on one infant-directed response, the grin-lipsmack. These comparisons showed that defeminization of the repertoire of infant-directed responses was measurable only in intact males. We conclude accordingly that prenatal androgens alone are not responsible for defeminization of this repertoire and that a contribution from postnatal androgens is likely to be necessary.     

Seasonal breeding in rhesus monkeys: Influence of the behavioral environment

The accepted model of breeding seasonality in rhesus monkeys states that females become reproductively active in response to an environmental cue and that males become sexually active in response to ovulating females. This model must be modified to include direct responses of the male to the physical environment, endocrine responses of males to sexual activity, and responses of the female to the sexual activation of fellow group members. The complex set of social stimuli that influences the breeding readiness of both sexes may serve to delimit more precisely the annual periods of conception and birth than would be the case if each individual responded only to the changing physical environment.     

Skeptical responding in rhesus monkeys (Macaca mulatta)

Signalers that misinform sufficiently open may become devalued as sources of information; however, “skepticism” and any comparison involved in testing reliability entail a cost that involves delays and energy expenditure. Skepticism may be less costly though, if, as a rule, animals are not equally skeptical of the signals of all conspecifics. Animals with the ability to recognize individual conspecifics and to recall past encounters with them may have the capacity to restrict skepticism to subsets of animals that are most likely to benefit from deception. We played tape-recorded alarm calls of high- and low-ranking rhesus monkeys(Macaca mulatta) to their groups in a feeding context once daily over 8 consecutive days at the Yerkes Primate Center Field Station. Over the sequence of playbacks, response was greater to the calls of high-ranking monkeys, adult response patterns were different from those of juveniles, and for adults especially, decline in responsiveness was punctuated by partial resurgences of response. These differences may be the consequence of the adults’ more extensive histories of interaction with group members that, though generally reliable, vary with respect to the potential benefits of deceptive signaling.     

Deciduous tooth dimensions in fetal rhesus monkeys from mothers with induced diabetes

Thirty-four measurements of the deciduous dentition in 21 fetal rhesus monkeys from diabetic mothers (FDM) and 36 nondiabetic fetuses were compared in order to assess the effects of induced maternal diabetes on the teeth of third-trimester fetuses. After exclusion of 14 variates due to significant age-related variation, univariate statistical analysis suggested a trend toward smaller teeth in the FDMs. Multivariate discriminant function analysis indicated not only a clear separation between the two groups, with molar breadths and some incisor lengths and breadths serving as the best discriminators, but also that the deciduous dental dimensions in FDMs are smaller than in nondiabetic fetuses.     

Relative numerical middle in rhesus monkeys

Animals show vast numerical competence in tasks that require both ordinal and cardinal numerical representations, but few studies have addressed whether animals can identify the numerical middle in a sequence. Two rhesus monkeys (Macaca mulatta) learned to select the middle dot in a horizontal sequence of three dots on a touchscreen. When subsequently presented with longer sequences composed of 5, 7 or 9 items, monkeys transferred the middle rule. Accuracy decreased as the length of the sequence increased. In a second test, we presented monkeys with asymmetrical sequences composed of nine items, where the numerical and spatial middle were distinct and both monkeys selected the numerical middle over the spatial middle. Our results demonstrate that rhesus macaques can extract an abstract numerical rule to bisect a discrete set of items.     

Atretogenic action of estrogen in rhesus monkeys: Effects of repeated treatment

The effects of 17β-estradiol (E₂), administered in Silastic capsules for 24 hours at intervals of 10 or 14 days, on follicular development and menstrual cycle characteristics were studied in 13 rhesus monkeys. In seven monkeys receiving E₂ at l0-day intervals for 50 treatment periods, new follicles frequently developed between treatments but usually regressed. In seven instances, the follicles persisted longer than expected but were steroidogenically suppressed and regressed spontaneously. Ovulation occurred in only two instances. In six monkeys receiving E₂ at 14-day intervals, new follicles developed regularly, with seven ovulations occurring in 37 treatment periods. A persistent anovulatory follicle was noted in only one instance. Menstruation occurred with equal frequency, and the interval from treatment to onset of menstruation was not significantly different regardless of treatment or the occurrence of ovulation; the intervals between menstruation approximated those of normal menstrual cycles. In general, following termination of treatment, menstrual cycles returned to normal quickly. These data indicate that E₂ administered intermittently at 10-day intervals effectively suppresses ovulation, and they provide new insight into the actions of E₂ on folliculogenesis in primates.     

Calcium,magnesium, and phosphorus content of hair from two populations of rhesus monkeys

The use of hair for the assessment of human mineral nutritional status is controversial, yet has potential because of the ease of collection and storage, and the high concentration of minerals in hair. This study generated baseline values for hair macromineral content in the most commonly used primate model for human nutrition and disease, the rhesus monkey. Hair digests from monkeys in Maryland (n=98) and Puerto Rico (n=208) were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Significant differences existed between the two populations for hair calcium (Ca), magnesium (Mg), and phosphorus (P) (P<0.01,P<0.001,P<0.02). Male hair had higher concentrations of Mg in specimens from the Puerto Rican population (P<0.001), whereas hair phosphorus was higher in female hair (P<0.02). There were no significant differences attributable to pregnancy status. Differences in hair content attributable to categorical age were found for Ca and Mg (P<0.001,P<0.01). Significant location differences paralleled dietary differences. These values therefore can be considered reference ranges for hair Ca, Mg, and P for free-ranging and caged rhesus monkeys. Preliminary reports of portions of these data were presented at the 69th Annual Meeting of the Federation of American Societies for Experimental Biology, April 1982, New Orleans, LA (B. M. Marriott, J. C. Smith, R. Jacobs, A. O. Jones, M. J. Kessler, and R. Rawlins,Fed. Proc. 41:770 [1982]) and in a symposium at the 6th Annual Meeting of the American Society of Primatologists, 1983, East Lansing, MI (B. Marriott, J. C. Smith, R. Jacobs, A. O. Lee Jones, R. Rawlins, and M. J. Kessler,Am. J. Primatol. 4(3):157 [1983]; B. Marriott, J. C. Smith, Jr., R. M. Jacobs, A. O. Lee Jones, R. Rawlins, and M. J. Kessler, inThe Cayo Santiago Macaques, R. Rawlins and M. J. Kessler, eds., SUNY Press, Albany, NY, pp. 219–231 [1986]).     

安徽恒河猴的微生物学和寄生虫学检测

对安徽省实验猕猴中心的安徽恒河猴进行了微生物（包括病毒和病原菌）和寄生虫检测。对恒河猴的病毒检测结果发现,猕猴疱疹病毒1型（BV）和猴痘病毒（SPV）抗体的阳性率分别为20．7％（6／29）和10．0％（2／20）,20只恒河猴中没有发现猴反转录D型病毒（SRV）、猴免疫缺陷病毒（SIV）和猴T细胞趋向性病毒Ⅰ型（STLV—1）的抗体。5只受检的人工繁育的安徽恒河猴没有感染沙门菌、皮肤病原真菌、志贺菌和结核分枝杆菌的这四种病原菌。肉眼检测恒河猴体表,未发现体外寄生虫。39份人工繁殖的恒河猴粪便样品的总寄生虫感染率为38．5％,检测到溶组织内阿米巴和5种蠕虫（粪类圆线虫、猴结节线虫、绦虫、钩虫、蛔虫）,感染率最高的是粪类圆线虫和猴结节线虫。本次调查表明,安徽恒河猴无特殊疾病,健康状况基本良好,可以建立普通级的实验恒河猴,实现安徽恒河猴的实验动物化。     

Water metabolic parameter changes in rhesus monkeys during exposure to prolonged restriction of motor activity

The objective of this investigation was to determine the effect of prolonged restriction of motor activity (hypokinesia [HK]) on several parameters of water metabolism in primates. The studies were performed on 12 rhesus monkeys aged 4–5 yr (5.10–6.85 kg) during the hypokinetic period of 90 d and during the prehypokinetic period of 30 d. They were divided into two equal groups: the first group was placed under ordinary vivarium conditions (vivarium control animals) and the second group was subjected to 90 d of HK (hypokinetic animals). For the simulation of the hypokinetic effect, the primates were immobilized on their abdomens in special tables. The legs of the monkeys were immobilized with hip and knee joints extended. The primates retained freedom of movement at elbow, wrist, and ankle. During the preexperimental period of 30 d and during the experimental period of 90 d, the following variables were determined: body weight, total body fluid content, specific total body fluid, mean fluid consumed and eliminated in urine, specific plasma resistance, hematocrit level, and plasma concentrations of sodium (Na) and potassium (K). In the hypokinetic primates, body weight decreased significantly when compared to the controls. Mean fluid intake, total body fluid, and specific total body fluid decreased, whereas mean daily fluid loss and specific mean daily fluid elimination increased significantly. Specific plasma resistance, hematocrit level, and plasma electrolyte concentrations increased significantly when compared to the control primates. It was concluded that prolonged restriction of motor activity induces significant changes in water metabolic parameters of primates leading in decreased total water content of the body.     

Sterilization and its behavioral effects on free-ranging female rhesus monkeys (Macaca mulatta).

In order to control population growth rates, a decision was made to sterilize most of the free-ranging, wild rhesus macaque females of Silver Springs, Florida. Between October 1987 and March 1988, the five females who had been sterilized and released in the fall of 1986 were matched with five intact females in a behavioral study. While there were differences between the behaviors of the sterilized and intact females, the differences can be attributed more to differences in age, rank, and other factors than to the sterilization. Clinical data collected and reported on the monkeys is unremarkable.