The relationship between maternal rank and companion choice in immature macaques (Macaca mulatta andM. radiata)

Eight bonnet and eight rhesus macaques, ranging from 5–8 months of age, were observed with respect to their choices of companions. These data were then correlated with the dominance ranks of the mothers of the companions involved. Preliminary results showed that the maternal ranks of the rhesus infants were significantly correlated with the maternal ranks of their companions; no such correlation could be demonstrated for the bonnet monkeys. Thus the partner choices of rhesus infants appeared to be more constrained than were those of the bonnets. The results were discussed in relation to the social systems of bonnet and rhesus macaques. Supported in part by faculty research grant D-552, Chancellor's Patent Fund DG #44, and by RR00169 to the California Primate Research Center.     

Of Least Concern? Range Extension by Rhesus Macaques (<Emphasis Type="BoldItalic">Macaca mulatta</Emphasis>) Threatens Long-Term Survival of Bonnet Macaques (<Emphasis Type="BoldItalic">M. radiata</Emphasis>) in Peninsular India

Rhesus and bonnet macaques are the 2 most common and widely distributed of the 8 macaque species of India. Rhesus macaques are widely distributed across southern and southeastern Asia, whereas bonnet macaques are restricted to peninsular India. We studied the current distributional limits of the 2 species, examined patterns of their coexistence in the interspecific border zones, and evaluated losses in the distributional range of bonnet macaques over the last 3 decades. Our results indicate that whereas rhesus macaques have extended their geographical range into the southern peninsula, bonnet macaques have been displaced from many areas within their former distributional range. The southern and the northern distributional limits for rhesus and bonnet macaques, respectively, currently run parallel to each other in the western part of the country, are separated by a large gap in central India, and converge on the eastern coast of the peninsula to form a distribution overlap zone. This overlap region is characterized by the presence of mixed-species troops, with pure troops of both species sometimes occurring even in close proximity to one another. The range extension of rhesus macaque—a natural process in some areas and a direct consequence of introduction by humans in other regions—poses grave implications for the endemic and declining populations of bonnet macaques in southern India.     

Behavior of nursery/peer-reared and mother-reared rhesus monkeys from birth through 2 years of age

The behavior of 8 nursery/peer-reared and 16 mother-only reared rhesus macaques was observed between birth and 5 months of age, with follow-up studies conducted when the animals were 10–21 months old and living in large social groups. Nursery-reared neonates were more awake, active, and irritable than mother-only reared monkeys. From 1 to 5 months of age the nursery/peer-reared animals exhibited a greater variety of behaviors than the mother-only reared infants, which spent the majority of the time in ventral contact with mothers. As juveniles the groups were indistinguishable with the exception of more self-directed behaviors observed in the nursery/peer-reared monkeys. Both rearing conditions, by virtue of their atypicality, imposed restrictions on social development. The behavioral similarity of the juveniles while in the large social group may be a function of maturation or due to the rehabilitative effect of the large social group.     

川金丝猴非母亲照料行为的影响因素及其母亲获益——以神农架川金丝猴投食群为例

灵长类社会中存在着非母亲成员(成年雌猴、青少年猴和成年雄猴)对婴儿的照料行为,即非母亲照料行为,该行为直接影响新生婴儿的存活与发育以及婴儿母亲的日常活动,是灵长类学研究领域的热点问题.本研究于2019年3月至2019年11月,采用焦点动物取样和瞬时扫描取样,探究了川金丝猴非母亲照料行为的影响因素及其对母亲活动分配的影响...     

Normal hematological and plasma biochemical parameters of the captive bonnet monkey (Maccaca radiata)

The bonnet monkey is being increasingly used as a model in biomedical research. However, unlike the rhesus monkey, very little information on the hematological and biochemical characteristics of blood plasma is available. Comparative data on plasma biochemical parameters vis-a-vis rhesus and human is essential for utilization of this species in biomedical research. Efforts were made to determine selected serum enzymes, glucose, triglycerides, blood urea nitrogen, creatinine, total protein, albumin, cholesterol, bilirubin, calcium, phosphorus, sodium, magnessium, potassium and total erythrocyte count, total leukocyte count, hemoglobin, PCV, ESR, and differential leukocyte count in groups of juvenile and adult bonnet monkeys of both sexes. The monkeys exhibited similar values for all the parameters in comparison to rhesus and human except for alkaline phosphatase. The value for alkaline phosphatase was 3–5 fold higher when compared to concentrations seen in rhesus monkeys and human beings. The investigation also describes the variations seen between adults and juveniles, as well as between the sexes. The data presented is valuable for scientists using this species of monkey as a human surrogate model.     

Of how much concern are the ‘least concern’ species? Distribution and conservation status of bonnet macaques,rhesus macaques and Hanuman langurs in Karnataka,India

We assessed the distribution and conservation status of bonnet macaques (Macaca radiata), rhesus macaques (Macaca mulatta) and Hanuman langurs (Semnopithecus entellus) in the state of Karnataka, India. Karnataka is situated in southwest India with an area of 191,791 km². A total of 9697 km of vehicular survey was made from November 2001 to July 2004. We also visited 107 temples/tourist spots to determine the presence of primates. Bonnet macaques and Hanuman langurs were widely distributed, whereas rhesus macaques were not found in the state. However, bonnet macaques were absent in a few districts in the northern plains and Hanuman langurs were absent in some districts of the southern plains. A total of 205 groups of bonnet macaques and 139 groups of Hanuman langurs were sighted. The relative encounter rate of both species differed across biogeographic zones. Bonnet macaques were largely encountered in the Western Ghats and the Southern Plateau whereas Hanuman langurs were abundant in the Western Ghats and Northern Plains. We found that bonnet macaques have been eliminated from about 48% temples/tourist spots where they occurred in the recent past. The Hanuman langur population of Dharwar–Haliyal Road was assessed during April 2003, and we found that the present population size was about 38% of a previous survey in 1961. Habitat change, hunting/trapping and translocation were the major factors causing a decline in the langur population.     

Restoration of sexual performance in old rhesus macaques paired with a preferred female partner

Experiments were undertaken to determine whether the decline in the ejaculation frequency of old male rhesus macaques is due to a decrease in physical capacity. In the first experiment, the capacity of old males to ejaculate in a series of biweekly tests was investigated. Six old (18–23 years) and six young (8– 12 years) male rhesus macaques were given 10-min tests of sexual behavior with nine different females chosen at random. The old males were also given 10-min tests with a preferred female, 1339. When the old males were tested with nine different females, their sexual performance (e.g., frequency of ejaculation) was significantly less than that of the young males, but their performance was comparable to that of young males in nine tests with female 1339. In a second experiment, the capacity of old males to show repeated ejaculations over a 3-hr period was tested. The same old and young males were given a 3-hr test with female 1339. The sexual performances (number of ejaculatory series completed and behavior displayed within each ejaculatory series) of the old males did not differ significantly from those of the young. Also, no significant differences in behavior were observed between young and old males during the first 10 min of the 3-hr tests. Our data show that the decline in the sexual performance of old rhesus males is not due to a decreased capacity to perform sexually or to physical debilitation.     

Male–Male Relationships in Lion-tailed Macaques (<Emphasis Type="Italic">Macaca silenus</Emphasis>) and Bonnet Macaques (<Emphasis Type="Italic">Macaca radiata</Emphasis>)

Socioecology suggests that female distribution in space is determined by the distribution of food resources and the male distribution is influenced by female distribution. Though studies have traditionally focused on females, males have received increasing attention in recent years. We compared male–male relationships in lion-tailed macaques and bonnet macaques. Because bonnet macaques have a high adult male:female sex ratio and are seasonal breeders whereas lion-tailed macaques have a low adult male:female sex ratio and are largely aseasonal breeders, we predicted that bonnet macaque males would be spatially and socially more tolerant of each other and would have less linear dominance relationships than lion-tailed macaques. We recorded male–male and male–female relationships in 1 group of wild macaques of each species via scan sampling and 1–0 sampling. The results revealed that lion-tailed macaque males largely remained at a distance from each other whereas bonnet macaque males remained in close proximity to one another. Lion-tailed macaque males were more agonistic toward each other whereas bonnet macaque males showed more affiliative interactions. The dominance hierarchy among lion-tailed macaque males was more linear than among bonnet macaque males. Our data support the hypothesis that the study of spatial structuring, temporality of interactions, and linearity of social relationships may contribute to a better understanding of macaque social systems.     

Age Differences in the Responses to Adult and Juvenile Alarm Calls by Bonnet Macaques (Macaca radiata)

This study examined the differential responses to alarm calls from juvenile and adult wild bonnet macaques ( Macaca radiata ) in two parks in southern India. Field studies of several mammalian species have reported that the alarm vocalizations of immature individuals are often treated by perceivers as less provocative than those of adults. This study documents such differences in response using field-recorded playbacks of juvenile and adult alarm vocalizations. To validate the use of playback vocalizations as proxies of natural calls, we compared the responses of bonnet macaques to playbacks of alarm vocalizations with responses engendered by natural alarm vocalizations. We found that the frequency of flight, latency to flee, and the frequency of scanning to vocalization playbacks and natural vocalizations were comparable, thus supporting the use of playbacks to compare the effects of adult and juvenile calls. Our results showed that adult alarm calls were more provocative than juvenile alarm calls, inducing greater frequencies of flight with faster reaction times. Conversely, juvenile alarm calls were more likely to engender scanning by adults, a result interpreted as reflecting the lack of reliability of juvenile calls. Finally, we found age differences in flight behavior to juvenile alarm calls and to playbacks of motorcycle engine sounds, with juveniles and subadults more likely to flee than adults after hearing such sounds. These findings might reflect an increased vulnerability to predators or a lack of experience in young bonnet macaques.     

Body Size and Proportions and Pelage Color of Free-Ranging Macaca mulatta from a Zone of Hybridization in Northeastern Thailand

Rhesus (Macaca mulatta) and long-tailed (M. fascicularis) macaques belong to the same species, and are parapatric within a zone that lies between 15° and 20° N on the Indochinese peninsula. Researchers have reported probable hybrids between the 2 species from that zone, but have not studied the extent of introgression. To test for phenotypic evidence of hybridization, we collected body mass, morphometrics (body size and proportions), and pelage color readings from free-ranging rhesus living close to the zonal boundary at Wat Tham Pa Mak Ho (WTPMH), Wang Saphun district, Loei province, northeastern Thailand (17°14′N, 101°47′E). Female WTPMH rhesus macaques (n =12) were 10–20% smaller, but with a greater relative tail length than the captive Chinese or Indian female rhesus. Female WTPMH were larger than the free-ranging long-tailed macaques, but with similar limb proportions and a shorter relative tail length. The WTPMH rhesus macaques also displayed the bipartite pelage color pattern typical of Macaca mulatta . The evidence suggests slight contribution of long-tailed macaques to the gene pool of the WTPMH population. Further sampling of other macaque populations within the zone and genetic analysis are essential to address better the question of hybridization. Determination of the distribution and range of biobehavioral variation of macaques within the zone is urgently needed, because their habitat is being rapidly destroyed by deforestation, and their demography and social structure are threatened by artificial disturbance.     

Differentiall behavioral and adrenocortical responses to stress among three macaque species

Behavioral and adrenocortical responses of rhesus (Macaca mulatta), bonnet (M. radiata), and crabeating (M. fascicularis) macaques were compared in their home cages, during exposure to novelty and during physical restraint. Both behavioral and adrenocortical responses differentiated species in each condition. In all conditions, post-test corticosteroid levels were highest for crabeaters and lowest for rhesus. Rhesus were the most active behaviorally, and bonnets were the most passive, while crabeaters exhibited the greatest signs of behavioral disturbance. Relationships between adrenocortical and behavioral responses varied between groups. Both adrenocortical and behavioral profiles were in accord with the behavior of these three species under more natural conditions. The role of psychophysiological responses in general behavioral dispositions toward the environment is discussed. It is concluded that behavioral dispositions, inclusive of psychophysiological responses, may vary qualitatively even among closely related primate species.     

Interspecific contrasts in responses of macaques to transport cage training

Corticosteroid values in response to brief confinement in a transport cage were compared between rhesus, bonnet, and crabeating macaques before and after they were trained to enter the cage. Behavioral data were collected to assess performance during training. Species differences were found both in training measures and in corticosteroid response to confinement in the transport cage after training. Bonnets took longer to train than rhesus or crabeaters. Rhesus showed the smallest adrenocortical response to cage confinement after training and crabeaters the greatest, suggesting that this group habituated more slowly to confinement than the other two groups. The results have implications for choice of experimental subject species and for management and husbandry of laboratory primates.     

Spruce grouse, a non-gregarious and sparsely distributed forest bird, shows synchronous nesting

Hatch dates, densities, age-structure, and production rates were documented for female spruce grouse (Dendragapus canadensis) in Alberta, Ontario, and New Brunswick, Canada, over a total of 17 years during 1970–1990. Objectives of analyses were to measure the magnitude of synchrony of hatch dates at different densities of females in different areas, determine whether synchrony differs between adults and yearlings, determine whether adults might influence the time and synchrony with which yearlings hatch clutches, and determine whether mean production of juveniles into late summer varies across the span of hatch dates. Hatch date synchrony was substantial in all areas: on average, 67% of all clutches each year hatched within 6.5–8.8 days, within areas, similar to that among colonial avian species. The extent of synchrony was not correlated well with female density, in contrast to a general prediction from Darling’s hypothesis for colonial species. Synchrony did not differ between yearlings and adults in all areas even though yearlings generally hatched clutches later than adults. Synchrony was not correlated well with an index of the magnitude of interaction between adults and yearlings, suggesting that adults had little if any effect on the timing of reproductive activity of yearlings. In contrast, median hatch dates of yearlings were 1–2 days earlier where adults were experimentally thinned than where adults were common. Production of juveniles into late summer did not vary across the span of hatch dates despite their synchronous temporal distribution, providing no evidence for an immediate adaptive value for synchronous nesting. Received: 23 March 1999 / Accepted: 14 November 1999     

Maternal gestational androgens are associated with decreased juvenile play in white-faced marmosets (Callithrix geoffroyi)

Exposure to androgens during prenatal development shapes both physiological and behavioral developmental trajectories. Notably, in rhesus macaques, prenatal androgen exposure has been shown to increase rough-and-tumble play, a prominent behavioral feature in males during the juvenile period in primates. While macaques are an Old World, polygamous species with marked sexually dimorphic behavior, New World callitrichine primates (marmosets and tamarins) live in cooperative breeding groups and are considered to be socially monogamous and exhibit minimal sexual dimorphism in social play, which suggests that androgen may affect this species in different ways compared to macaques. In addition, we previously described considerable variation in maternal androgen production during gestation in marmosets. Here we tested the association between this variation and variation in offspring rough-and-tumble play patterns in both males and females. We measured testosterone and androstenedione levels in urine samples collected from pregnant marmoset mothers and then observed their offspring's play behavior as juveniles (5-10 months of age). In contrast to findings in rhesus macaques, hierarchical regression analyses showed that higher gestational testosterone levels, primarily in the second semester, were associated with decreased rough-and-tumble play in juveniles, and this relationship appears to be driven more so by males than females. We found no reliable associations between gestational androstenedione and juvenile play behavior. Our findings provide evidence to suggest that normative variation in levels of maternal androgen during gestation may influence developmental behavioral trajectories in marmosets in a way that contradicts previous findings in Old World primates.     

Behaviour of juvenile bonnet monkey before and after his mother gives birth to a new baby

Five juveniles in a free living group of bonnet monkeys were observed before and after their mothers gave births to new babies. The human infant is said to be a rival of his sibling because the new born baby becomes a centre of mother’s affection and the old infant starts feeling neglected. The present study was planned to observe this phenomenon in monkeys. It has been concluded that the so called sibling rivalry does not exist in monkeys.     

Mother-infant contact and maternal maintenance activities among free-ranging rhesus monkeys

Mother-infant dyads were observed among three populations of rhesus monkeys (Macaca mulatta) in India and Nepal. Physical contact between mothers and infants, essential for effective maternal care in rhesus, was found to be influenced by the mothers' feeding behavior. As early as the second week of life, infants exhibited a diminished probability of being in contact with their mothers if their mothers were feeding rather than resting. Rhesus mothers disproportionately rejected their infants within feeding contexts, indicating that mothers were actively discouraging contact attempts by their infants during feeding bouts—perhaps because an active infant, if it remained in contact, would diminish its mother's foraging efficiency. In contrast to the mothers' feeding behavior, mother-infant contact was found to be little influenced by maternal locomotion. Most infants were found to be neither disproportionately in, nor out of contact while their mothers were in motion. However, as the amount of time mothers spent walking increased, so did the probability that infants would be carried. These data suggest that rhesus mothers behave so as to minimize their energetic costs during locomotion.     

Reactions of nuclear-family–reared rhesus macaques to the births of younger siblings

A group of juvenile rhesus macaques (Macaca mulatta) living in a nuclear-family laboratory environment was studied to determine their responses to the births of siblings. The frequencies of interactions with family members (mothers, fathers, and new siblings) and nonfamily (peers, unrelated infants, and unrelated adults) were studied over both the year preceding and the year following sibling birth. The frequencies of specific behaviors in each of those interactions and the frequencies of interactions in each area of the nuclear-family unit (home cage, play area, or other families' cage) were also examined. After new siblings arrived, several measures of interactions with mothers, fathers, and new siblings increased significantly; by contrast interactions with peers decreased substantially over the post-birth year. Although the frequency of interactions in home cages remained stable over the 2-year period, interactions outside of the subjects' home cages decreased significantly after siblings were born. An additional subject group whose mothers became pregnant but failed to deliver viable offspring showed no significant changes in total levels of interactions with peers; they did, however, exhibit increases in some interactions with unrelated infants and adults. Female juveniles interacted with new siblings significantly more often than did males when siblings were less than 6 months old, but as siblings grew older (6–12 months), females' levels of interaction with them fell to a level equal to that of males. In the nuclear-family social structure, the birth of a sibling resulted in an increased emphasis on family interactions at the expense of peer interactions.     

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.     

Mother–infant relationships and maternal estrogen metabolites changes in macaques (<Emphasis Type="Italic">Macaca fuscata,M. mulatta</Emphasis>)

This research assessed mother–infant relationships in rhesus and Japanese macaques living in analogous captive social groups, and monitored changes in the levels of excreted estrogen metabolites during the peripartum period. Each mother–infant pair was focally observed 3 h per week during the first 12 weeks of life of newborns. Fecal samples were collected twice a week from each mother, starting 4 weeks before delivery and ending 4 weeks after delivery. Infant-directed behaviors appeared to be consistently less protective/controlling and more rejecting in rhesus macaques than in Japanese macaques. Estrogen metabolite levels during the perinatal period were, on average, 3-fold higher in Japanese macaques and showed a sharp increase during the last weeks of pregnancy only in the Japanese macaque group. Considering the ecological and behavioral similarities between Japanese and rhesus macaques, the divergence between the two species in the onset and maintenance of maternal behavior was unexpected. This was possibly linked to the difference in the overall body size and life history, and to the striking divergence in estrogen metabolite variation during the peripartum period. Group size, social relationships, and average age of individuals in the two captive groups were not clearly involved in the recorded differences in maternal behavior. Electronic Publication     

Adult male-infant interactions in wild muriquis (Brachyteles arachnoides hypoxanthus)

We examined adult male-infant interactions in wild muriquis (Brachyteles arachnoides hypoxanthus), a species in which close relatedness among philopatric males and high paternity uncertainty should minimize both aggressive and affiliative behavior by males toward infants. As expected, male-infant interactions were extremely rare during this 10-month field study. None were observed in over 236 hr of observation on a cohort of six infants (0 – 13 months old). The 29 interactions observed ad lib involved 5 of the 6 infants and 9 of the 16 adult males in the group. All of the male-infant interactions were affiliative, but extremely brief. The median duration of interactions was only 0.33 min, and none lasted longer than 1.52 min. Infants always initiated, and nearly always terminated, their interactions with adult males. The indifference that appears to characterize muriqui male-infant interactions differs from the ways in which other male primates interact with infants when protection of genetic interests or investment in mating effort are involved.