Social grooming in Tonkean macaques (Macaca tonkeana)

The distribution, form, and contexts of occurrence of social grooming were studied in two captive groups of Tonkean macaques (Macaca tonkeana), using interaction-dependent sampling. The social events surrounding grooming had little influence on its form, the participants' behavior being shaped mainly by physical constraints. Adult females were most often involved in grooming interactions. Grooming between adult females appeared more intimate than that between adult males and females. Kinship and dominance had no effect on the form or distribution of social grooming among adult females. It is concluded that social systems that are characterized by mild dominance relations allow individuals the freedom to interact in the way and with whom they wish.     

Hand preferences on unimanual and bimanual tasks in Tonkean macaques (Macaca tonkeana)

This is the first study to examine hand preferences in Tonkean macaques on a bimanual task. One of our objectives was to continue the move toward greater task standardization, in order to facilitate comparisons between species and studies on handedness. The main aim was to test and determine task robustness, by varying intra‐task complexity. To this end, we administered several different tasks to the subjects: two unimanual tasks (grasping task featuring items of different sizes) and three coordinated bimanual tasks (tube task involving different materials, weights, and diameters). Although we found no significant hand preference in either task at the group level, the macaques were more strongly lateralized for small items than for large ones in the unimanual grasping task. Moreover, the absence of a correlation between these two versions of the unimanual task confirmed the weakness of this grasping task for assessing handedness. Regarding the bimanual tube task, no difference was found between the three versions in either the direction or the strength of hand preference. Moreover, the highly correlated hand preferences between these three versions suggest that the tube task provides a more robust means of measuring manual preferences. Am J Phys Anthropol 152:315–321, 2013. © 2013 Wiley Periodicals, Inc.     

Ranging patterns and habitat use of Sulawesi Tonkean macaques (Macaca tonkeana) in a human-modified habitat

The goal of this study was to investigate the ecological flexibility of Tonkean macaques (Macaca tonkeana) by examining how they respond to human-induced habitat alteration. To do so, I observed movement patterns, forest strata use, microhabitat use, and home range use in two groups that occupied habitats with different levels of human alteration and habitat quality in Lore Lindu National Park, Sulawesi, Indonesia. The group occupying the heavily altered habitat (Anca) spent a significantly greater proportion of time traveling on the ground than the group in minimally altered habitat (CH), and significantly more time than expected in microhabitats within their range that were characterized by greater alteration (e.g., agroforestry areas). There was no significant difference between the two groups in daily path length, despite differences in group size. The Anca group exhibited a greater home range area per individual than the CH group, and utilized a more limited area within their home range with greater intensity, relative to the CH group. Tonkean macaques therefore show considerable flexibility in response to anthropogenic disturbance by adjusting their use of forest strata to facilitate travel and increase foraging opportunities and by intensively using particular areas within their home range where known resources are present and predictably available.     

Long-term data on basic reproductive parameters and evaluation of endocrine,morphological, and behavioral measures for monitoring reproductive status in a group of semifree-ranging Tonkean macaques (Macaca tonkeana)

Cycle and gestation lengths, menstruation patterns, female genital swelling characteristics, and male-female consortship durations are reported in a semifree-ranging group of Tonkean macaques (Macaca tonkeana) studied over a 12 year period. In addition, profiles of urinary estrone conjugates (E1C) and immunoreactive pregnanediol glucuronide (PdG) throughout four complete menstrual cycles in two females and three full-term pregnancies are presented. Based on intermenstrual intervals, a mean cycle length of 37–41 days (n = 55 cycles in 10 females) was found. Gestation length averaged 173 days (n = 27 pregnancies in eight females). Measurement of PdG immunoreactivity in urine revealed a cyclic pattern with a 5–15-fold increase between follicular and luteal phase concentrations, suggesting that PdG is a reliable indicator of ovarian cyclicity and luteal function. In contrast to PdG, E1C excretion showed no clear pattern throughout the cycle; however, highest values of E1C were usually found shortly before the onset of the luteal phase PdG rise at the presumed time of ovulation. Levels of both hormones were elevated during the first half of gestation and showed a marked increase throughout the second half, with maximum E1C concentrations being up to 100-fold higher than nonpregnant levels. Consortships by the male and occurrence of female genital swelling were long lasting (on average 5–10 days and 13 days, respectively) and were restricted to the follicular phase of the cycle. The day of maximal swelling and day of detumescence as well as the end of male consortship were closely associated with the periovulatory period. Swellings and consortships were longer following lactational ammenorhea than for subsequent cycles. The evolutionary significance of the cyclical changes undergone by females upon their relations with males is discussed. © 1996 Wiley-Liss, Inc.     

Sexual strategies of female Japanese macaques (Macaca fuscata)

Evidence is reviewed that female Japanese macaques have multiple male mating partners when they are available and show a preference for mating with sexually unfamiliar males. Several lines of evidence suggest that this aspect of female sexual behavior results in the offspring of an individual female being sired by more than one male thereby maintaining the genetic diversity of the troop. Evidence is presented in this paper that a decrease in the number of adult troop males and a lack of extra-troop migrant males in the Arashiyama West troop of Japanese macaques following transplantation to a ranch in south Texas had consequences for the sexual behavior of the females.     

Semi-free breeding of tropical Celebes macaques (Macaca tonkeana) in a continental European climate.

Celebes macaques have been successfully bred for four years in a free-ranging colony in French pre-Alps where they are exposed to continental European climate and temperature variation of 65 centigrades.     

Manipulation of objects in a captive group of lion-tailed macaques (Macaca silenus)

The purpose of this study was to investigate the manipulative propensities of a captive group of lion-tailed macaques (Macaca silenus). Simple natural objects (browse and bamboo poles) were provided regularly in the home cage. Findings indicate richness in the frequency and form of manipulative activities, with juvenile males manipulating the test objects more frequently and exhibiting more goal-directed manipulative activity than adult females. A variety of goal-directed manipulative activities (use of objects to act as ladders, to apply leverage, and to create perches) occurred spontaneously, with some instances involving joint action or social use. These data are consistent with the hypotheses that macaques possess extensive capacities for object exploration and social facilitation, and that an evolutionary history of omnivorous foraging habits correlates positively with the expression of anomalous sensorimotor skills.     

Early predictors of self-biting in socially-housed rhesus macaques (Macaca mulatta)

The development of self-biting behavior in captive monkeys is little understood and poses a serious risk to their well-being. Although early rearing conditions may influence the expression of this behavior, not all animals reared under similar conditions self-bite. The purpose of this study was to examine the effects of three rearing conditions on biting behavior and to determine whether early infant behavior can predict later self-biting. The subjects were 370 rhesus macaques born at the National Institutes of Health (NIH) Animal Center between 1994 and 2004. They were reared under three conditions: mother-reared in social groups (n=183), peer-reared in groups of four (n=84), and surrogate-peer-reared (n=103). Significantly more surrogate-peer-reared animals self-bit compared to peer-only or mother-reared animals. There was no sex difference in self-biting, but this result may have been affected by a sex bias in the number of observations. The durations of behaviors exhibited by the surrogate-peer-reared subjects were recorded in 5-min sessions twice a week from 2 to 6 months of age while the animals were in their home cages and play groups. In the play-group situation, surrogate-peer-reared subjects who later self-bit were found to be less social and exhibited less social clinging than those that did not self-bite. Home-cage behavior did not predict later self-biting, but it did change with increasing age: surrogate clinging and self-mouthing decreased, while environmental exploration increased. Our findings suggest that surrogate rearing in combination with lower levels of social contact during play may be risk factors for the later development of self-biting behavior.     

Communal roosting and formation of sleeping clusters in barbary macaques (Macaca sylvanus)

Sleeping cluster composition and distribution were studied in a semi-free-ranging population of 174 Barbary macaques (Macaca sylvanus) in Rocamadour/France. Over a period of 2 months 341 sleeping clusters comprising 754 animals were recorded as animals left the sleeping trees. To control for nocturnal activities five observation periods were conducted, each of which covered a complete night. Sleeping partners were selected from a particular set of individuals. From night to night there was considerable fluctuation among the individuals, which finally formed a sleeping cluster. Preferred size of sleeping clusters was two and three individuals per cluster. The majority of females spent the nights in body contact to infants or female juveniles; whereas males either slept alone or with older male juveniles. Adult males and females never shared a sleeping cluster. During the night the animals showed hardly any locomotive and vocal activity. Sleeping clusters remained stable until dissociation the next morning. © 1992 Wiley-Liss, Inc.     

Social responding to mirrors in rhesus macaques (Macaca mulatta): Effects of changing mirror location

Two rhesus macaques (Macaca mulatta) with a lifetime of continuous exposure to mirrors showed a dramatic and reliable reinstatement of social behavior directed toward the mirror when it was simply moved to a new location. These data are discussed in the context of repeated failures to find self-recognition in monkeys and several recent claims that a cessation of social behavior directed toward mirrors can be used as evidence for the beginning of self-recognition in nonhuman primates.     

Play behavior in immature moor macaques (Macaca maura) and Japanese macaques (Macaca fuscata)

Play is widespread across mammalian taxa, but species strongly vary in the ways they play. In less despotic primate species (i.e., with less steep dominance hierarchies, less severe conflicts, and more reconciliation), play has been described as being more frequent, cooperative, and freely expressed. To study the link between social play and dominance style, we compared play behavior in free-ranging infants, juveniles and subadults of more despotic Japanese macaques (Macaca fuscata, N = 24) and less despotic moor macaques (Macaca maura, N = 17). We found interspecific differences in play behavior that corresponded with the contrasting dominance styles of the study species, largely confirming our predictions. In particular, moor macaques spent a larger proportion of time in solitary and social play than Japanese macaques, while Japanese macaques spent a larger proportion of time in grooming interactions. In moor macaques, play sessions included more players, a larger variety of play behaviors, greater play face rates, a greater proportion of time in contact play, and a higher rate of reciprocal play-biting than in Japanese macaques. Aggressive escalations were not common, but more frequent in Japanese macaques. Finally, a higher frequency of play faces during play sessions predicted the occurrence of more reciprocal play-bites, but not the proportion of time spent in contact play behaviors. Additional studies on other groups and species will allow a better understanding of the link between dominance style and social play.     

The effects of temporary cover on the behavior of socially housed stumptailed macaques (Macaca arctoides)

To examine the effects of the provision of temporary cover on the behavior of stumptailed macaques (Macaca arctoides), a single group of 26 animals was observed during 25 testing periods over 7.5 months. During each testing period, the group was observed under two conditions. In the Cover condition, two solid temporary walls 9.6 m in length, were erected within the animals' living compound. In the No-Cover condition, the wall materials were stacked against one solid exterior wall of the compound. The provision of cover significantly reduced the levels of contact aggression, proximity between animals, and locomotion, and reduced the ability of the dominant male to monopolize copulations. It did not effect other measures of affiliation. Inconsistencies between these results and those of other published studies suggest that, while cover can have a significant influence on some kinds of social behavior in some situations, generalizations about the benefits of providing cover to captive animals may be premature.     

Decrease in sexual initiative and responsiveness in female rhesus macaques (Macaca mulatta) during pregnancy

Although the sexual behavior of female rhesus macaques (Macaca mulatta) has been reported to decrease during pregnancy, systematic studies have been largely confined to reports of male behavior. Therefore, we designed a study to examine changes in female sexual behavior during pregnancy. Six cycling multiparous female rhesus macaques were paired during the periovulatory period of the menstrual cycle and during the first and second halves of pregnancy with six sexually experienced males of the same species. Each female was paired with the same male in all tests. The means of the behavioral measures scored on days 11–13 of the menstrual cycle, 35–56 of pregnancy, and 147–168 of pregnancy were compared. Females showed a significant decrease in the present contact ratio and the rate of threat-aways during pregnancy. Males showed lower rates of threatening-away, contacting, mounting, intromitting, and ejaculating when females were pregnant. The extent to which the decrease in male sexual behavior can be accounted for by an increase in female rejection is uncertain, but it is probably as significant as any loss of attractiveness that might accompany pregnancy.     

Positional behavior of long-tailed macaques (Macaca fascicularis) in northern Sumatra

Although the majority of extant primates are described as "quadrupedal," there is little information available from natural habitats on the locomotor and postural behavior of arboreal primate quadrupeds that are not specialized for leaping. To clarify varieties of quadrupedal movement, a quantitative field study of the positional behavior of a highly arboreal cercopithecine, Macaca fascicularis, was conducted in northern Sumatra. At least 70% of locomotion in travel, foraging, and feeding was movement along continuous substrates by quadrupedalism and vertical climbing. Another 14-25% of locomotion was across substrates by pronograde clambering and vertical clambering. The highest frequency of clambering occurred in foraging for insects, and on the average smaller substrates were used in clambering than during quadrupedal movement. All postural behavior during foraging and feeding was above-substrate, largely sitting. Locomotion across substrates requires grasping branches of diverse orientations, sometimes displaced away from the animal's body. The relatively low frequency of across-substrate locomotion appears consistent with published analyses of cercopithecoid postcranial morphology, indicating specialization for stability of limb joints and use of limbs in parasagittal movements, but confirmation of this association awaits interspecific comparisons that make the distinction between along- and across-substrate forms of locomotion. It is suggested that pronograde clambering as defined in this study was likely a positional mode of considerable importance in the repertoire of Proconsul africanus and is a plausible early stage in the evolution of later hominoid morphology and locomotor behavior.     

Menstrual-cycle phase and sexual behavior in semi-free-ranging stumptail macaques (Macaca arctoides)

The sexual behavior and female reproductive cycles of a group of island-dwelling stumptail macaques (Macaca arctoides)were monitored over a 6-month period, yielding 530 observation hr and 268 copulations. Compared to nondominant males, the dominant male copulated at a relatively high rate throughout the cycle, but largely with one high-ranking female. The non-dominant males copulated most frequently at midcycle. Female presenting was highest at midcycle, but only to the dominant male. Cross-study discrepancies may be due to different observation methods and restricted environmental conditions that mask female-initiated sexual behavior. The more naturalistic setting of this study allowed for a fuller expression of proceptivity. Contrary to some previous conclusions, present findings suggest that both hormonal and socioenvironmental factors influence the patterns of sexual behavior found in stumptail macaque colonies.     

Formal biting in stumptailed macaques (Macaca arctoides)

Form and function of a specific kind of biting were studied in a captive group of stumptailed macaques (Macaca arctoides) composed of 1 adult male and 10 females. Behavior patterns were recorded with all occurrence and scan sampling techniques. Formal biting consisted of slowly gripping with teeth a part of the body of an apparently willing partner, most often the forearms, lips, or eyebrows. It may occur either following an agonistic interaction or outside the context of aggression. Such biting was directed from dominants towards subordinates, and appeared especially frequently between individuals having frequent agonistic interactions. It is concluded that this behavior represents a ritualized interaction expressing formal dominance between partners.     

Patterns of sexual behavior in male macaques

One large social group of each of three species of macaques (Macaca mulatta, M. fascicularis, M. radiata), housed in half-acre field cages at the California Primate Research Center, were observed for a total of 150 h. Data on sexual behavior and dominance interactions were recorded by pairs of experienced observers using a focal animal technique. Single or multiple mount-to-ejaculation sequences, number of thrusts per mount, number of mounts per sequence, duration of mounts per sequence, duration of sequences, social rank and frequency of sexual activity were recorded for each adult male. M. mulatta used a multiple mount-to-ejaculation (MME) pattern in 91% of their copulations. M. radiata used a single mount-to-ejaculation (SME) pattern in 91% of their copulations. M. fascicularis used both patterns—53% MME and 47% SME. A positive correlation was found between rank and sexual activity in fascicularis and mulatta males. A negative correlation between rank and sexual activity was found in radiata males and also a positive correlation between rank and age indicating that the youngest and most subordinate radiata males were the most sexually active males. In reviewing the literature, a relationship between degree of intermale competition, intermale tolerance and type of mounting pattern was revealed. Macaque species that primarily use an SME pattern also show sa high degree of intermale tolerance and little interrnale competition. Macaque species that primarily use an MME pattern typically show a high degree of intermale competition and a low degree of intermale tolerance. Possible events leading to such relationships are discussed.