Inter-population differences in the time budgets of bonnet monkeys (Macaca radiata)

Time budgets for five major activities viz., Passive Sitting, Locomotion, Foraging, Social Behaviour, and Self-directed Behaviours were recorded for bonnet monkeys inhabiting forest, urban, and rural habitats. The time budgets were further classified into those of various age-sex classes. Significant inter-population differences were found in group size, social behaviour, foraging, and locomotion, which are discussed in relation to the habitat features.     

Social interactions of juvenile female bonnet monkeys,Macaca radiata

This study reports observations on juvenile female bonnet macaques (Macaca radiata) in a field cage environment. Interaction and proximity data collected on different age classes of juvenile females indicate distinct changes in social behavior from the time a female is weaned until her first pregnancy. Behavioral development includes an increase in solitary behavior, an early disinterest in younger animals, and a surprisingly low interaction rate with relatives. Important aspects of ontogeny are lost in analyses that treat all juvenile females as a single age-class. This research was supported partially by US PHS Grant No. RR00169.     

Vocal communication of wild bonnet macaques (Macaca radiata)

Field observations and spectrographic analyses of sound recordings of South Indian bonnet macaques revealed a vocal repertoire of at least 25 basic patterns. The repertoire consists of well separated sound classes and acoustic categories connected by structural intergradation. Besides structural variations within and between different elements of the repertoire, the vocal system ofMacaca radiata is characterized by regular combinations of particular basic patterns. These combinations occurred not only between calls of similar structure and function but also between calls usually emitted in entirely different social contexts. According to the qualitative analysis, sex-specific asymmetries of the vocal behaviour were less pronounced than age-dependent characteristics. The comparison of clear call vocalizations ofMacaca radiata andM. fuscata revealed significant species-specific differences on the structural and the behavioural level. Evaluations of the structural features of alarm calls of various macaque species imply marked differences between members of thefascicularis group andsinica group on one hand and thesilenus group andarctoides group on the other.     

Malignant fibrous histiocytoma in a bonnet macaque (Macaca radiata)

Spontaneous sarcomas, not associated with an underlying disease, appear to be relatively rare in nonhuman primates. Since 1970, there have been few reported cases of naturally-occurring sarcomas of any kind in these species. A malignant histiocytoma and malignant fibrous histiocytoma have been described in a rhesus macaque and baboon, respectively. A malignant fibrous histiocytoma is defined as a sarcoma of varied pattern consisting of a mixture of histiocytic and fibroblastic elements. It is thought that the two cells types arise from a common precursor or that the fibroblastic elements are derived from the histiocytes. These tumors are relatively common in humans. Here we report a case of spontaneously-occurring malignant fibrous histiocytoma in an adult bonnet macaque.     

Nasal cavity carcinosarcoma in a bonnet macaque (Macaca radiata)

An example of a rare, highly aggressive malignant intranasal neoplasm in a male Bonnet macaque is presented. The tumor invaded the bony orbit, distorted the position of the globe, and metastasized to regional lymph nodes and lungs. Histologically the tumor was composed of both mesenchymal and epithelial components and probably was of minor salivary gland origin.     

Growth and reproductive parameters of bonnet monkey (Macaca radiata)

The present paper summarizes some of the important biological and physiological data recorded over a 30-year period on the biology of bonnet monkeys in captivity. Data on sexual maturity, menstrual cyclicity, general behaviour, endocrine profile, reproductive physiology, gestation, parturition, postpartum amenorrhoea in the female, and sexual maturity, hormone profile, and seasonal variation in sperm count of the male monkeys are presented. In addition to the biological values, weights of selected organs, vertebral and dental pattern are also presented. Menarche occurred at an age of 36±4 months and the first conception in the colony occurred at an age of 54±4 months. The average menstrual cycle length was 28±4.3 days. Majority of monkeys did not cycle regularly during March–June during which the temperature reached a peak. The pregnancy index of the colony was 80% with controlled breeding. The gestation period was 166±5 days with 6–7 months postpartum amenorrhoea. Males attained sexual maturity by the age of 6–7 years and exhibited the characteristic nocturnal surge of serum testosterone at this age and sperm concentration ranged from 116–799 millions/ejaculate.     

Impact of hyperprolactinaemia on testicular neutral lipids and phospholipids in mature bonnet monkeys, Macaca radiata (Geoffroy)

Impact of hyperprolactinaemia, induced by daily injection of ovine prolactin (250 micrograms/kg body weight, ip for 30 days) on testicular lipids was studied in M. radiata. Wet weights of testis and accessory sex organs decreased in hyperprolactinaemic monkeys. Even though total lipids in the testis did not show any significant change, total cholesterol and total glyceride glycerol decreased. While all fractions of testicular neutral lipids showed a perceptible decrease, phosphatidic acid, phosphatidyl ethanolamine and phosphatidyl choline increased in hyperprolactinaemic monkeys. Hyperprolactinaemia appears to influence male fertility by altering the composition of testicular neutral lipids and phospholipids.     

Outcast males and social structure among bonnet macaques (Macaca radiata)

Outcast males are a regular feature of rhesus (Macaca mulatta) and Japanese (M. fuscata) macaque societies but are rare among bonnet macaques (M. radiata). Apparently bonnets have other solutions than ostracism for their social problems. For example, in many troops the male-female ratio ranges from 0.7?1.0+; and, as the young adult males grow to full social and physical maturity, they remain in the troop and participate actively in social relationships. A few troops of bonnet macaques, however, have a network of social relationships which prevents the young males from being integrated into the social system; in some of these cases, male isolation occurs. A comparison of the social relations between males in bonnet macaque societies of both types suggests that societies with strong male-male bonds accommodate their growing males better than those with highly individual males.     

Characteristics of the social life of bonnet macaques (Macaca radiata)

The social behavior of wild bonnet macaques impresses upon us a peculiality and uniqueness which is different from other macaques. Although there is a clear-cut ranking relationship among adult males and they carry out their proper social roles according to each situation, many social behaviors are carried out independently of or ignoring the ranking order. The animals are organized in a flexible and tolerant social unit, but they don't abandon the advantages of group life.The uniqueness of bonnet behavior and society is recognized to be related to the highly developed individuality of this species.     

Studies on ovarian quiescence in the lactating bonnet monkey (Macaca radiata)

Lactating bonnet monkeys were used as a model to understand the mechanism of ovarian quiescence during lactation. The ovary of the bonnet monkey in the 3rd month of lactation responds well to exogenous pregnant mare serum gonadotropin stimulation with serum estrogen values reaching maximal levels by day 3 of the gonadotropin injection. The adminstration of ovine prolactin to such monkeys significantly inhibited the ovarian responsiveness to exogenous gonadotropin. The responsiveness of the pituitary of the lactating monkey (in the 3rd month of lactation) to luteinizing hormone releasing hormone injection was suppressed and supplementation with exogenous prolactin further accentuating this effect. The relative ability of chlorpromazine given intravenously/intramuscularly/intranasally to enhance endogenous prolactin levels was assessed. During the first 5 months of lactation when the basal prolactin levels were high, the luteinizing hormone levels were low. As the suckling stimulus reduces and prolactin levels fall, luteinizing hormone levels increase, the first post-parturient mensus occurring by 218 ± 4 days. This event was postponed by 3 months on increasing endogenous prolactin levels by administering chlorpromazine (250 μg/day by intranasal mode) over a 5 day period every month starting from the 3rd month of lactation.     

Relationship between testosterone and hepatic lipids in mature male bonnet monkeys, Macaca radiata (Geoffroy).

Administration of testosterone propionate (TP; 1 mg/kg body weight/day; im, for 30 days) to mature male bonnet monkeys, decreased total lipids, glyceride glycerol and cholesterol concentrations in hepatic tissue. The decrease in glyceride glycerol was due to decrease in monoacyl and triacyl glycerol. Both, free and esterified cholesterol were decreased after testosterone administration. Eventhough, total phospholipid was not significantly altered, phosphatidylserine and cardiolipin were increased, due to testosterone administration. Testosterone inhibited NADP-isocitrate dehydrogenase activity in liver. The findings suggest that testosterone acts as a lipolytic hormone and its action may be direct through its specific receptors in liver.     

Long-term contraceptive efficacy of vaccine of ovine follicle-stimulating hormone in male bonnet monkeys (Macaca radiata).

A group of ten healthy fertile adult male bonnet monkeys were actively immunized using procedures acceptable for human use with pure follicle-stimulating hormone (oFSH) isolated from sheep pituitaries. The vaccine elicited an immunogenic response in all ten monkeys; the antibody-binding capacity, determined by Scatchard analysis, varied from 3 to 18 micrograms oFSH ml-1, the binding affinity ranging from 0.13 to 2.0 x 10(10) mol-1. A substantial population of antibodies against oFSH crossreacted with 125I-labelled human (h) FSH, used here as a representative ligand of primate FSH. The bioneutralization activity of the antisera assessed by a specific bioassay in vitro, when the antibody titre was high, was 6.9 +/- 0.18 micrograms hFSH ml-1. Immunization for 4.7-5.7 years did not affect the health and libido of the animals. Concentration of testosterone in serum remained normal throughout the study, but, within 150 days of immunization, there was a marked decrease (75-100%) in the number of spermatozoa in seminal ejaculates. Oligospermic status interspersed with azoospermia was maintained by periodic boosting. The fertility of these animals was monitored between 6 months and 2 years after primary immunization. All the ten animals proved infertile in repeated mating experiments with females of proven fertility. After stopping booster injections, nine of ten animals regained fertility, but the time taken for this depended upon the rate of decline of antibody titres. Re-boosting these monkeys with 100 micrograms oFSH after confirming that recovery had occurred revealed prompt increases in antibody titres followed once again by onset of oligo-azoospermia and infertility, underscoring the specificity of immunization effect. The immunized monkeys, apart from being acutely oligospermic, ejaculated spermatozoa that were markedly deficient in key acrosomal enzymes, such as acrosin and hyaluronidase, and motility as well as in their ability to penetrate a gel in vitro, suggesting that the infertility observed was due to gross reductions in the numbers of spermatozoa that could effectively interact with the oocyte and cause successful fertilization.     

Granulosa theca cell tumor with luteoma in the ovary of a bonnet monkey (Macaca radiata)

A mass was identified on the left caudal region of the abdomen in a 13-year-old bonnet monkey (Macaca radiata). The mass was excised and diagnosed as granulosa theca cell tumor accompanied with luteoma based on the microscopic findings. Morphologically it appeared pink, round, firm multilobulated measured approximately 5 x 3 x 2.5 cm in dimension. Histologically the luteoma composed of polyhedral cells with pale strained vacuolated cytoplasm, centrally located nuclei with distinct cytoplasmic borders. Granulosa theca cell tumor appeared as densely packed spindle shaped fusiform cells arranged in interlacing bundles and whorled pattern with neoplastic cells appearing irregular shaped solid sheets. The concomitant development of granulosa theca cell tumor with luteoma in a single ovary is very rare and is the first reported case in a bonnet macaque to our knowledge.     

Normal hematological indices, blood chemistry and histology and ultrastructure of pancreatic islets in the wild Indian bonnet monkeys (Macaca radiata radiata)

The present study is aimed at determining some haematological and biochemical parameters in the wild Indian bonnet monkeys as also the microscopic and ultrastructural characteristics of their pancreatic islets. Adult wild Indian bonnet monkeys (Macaca radiata radiata) of both sexes weighing between 2.5 and 4 kg were used in these experiments. Their platelet, reticulocyte and total leukocyte counts and the blood concentrations of hemoglobin and plasma proteins and the serum concentrations of aspartate amino transferase, alanine amino transferase and calcium are similar to the values reported for M. mulatta. Plasma glucose is lower when compared with reported values of M. mulatta and M. fascicularis. Insulin levels are comparable with those of M. mulatta and M. nigra. Histology of islets is similar to that of humans. Ovoid cell collections of islet cells are scattered throughout the pancreas. Ultrastructure of A, B and D cells is similar to humans. These findings suggest that this relatively underutilized macaques may be a suitable model for biomedical research.     

Hematological and serum biochemical indices in healthy bonnet macaques (Macaca radiata)

Background Blood reference values for bonnet macaques (Macaca radiata) are limited. The goal of this study was to determine reference ranges for hematological and serum biochemical indices in healthy, socially housed bonnet macaques for males and females over a range of ages. Methods Blood hematological and serum biochemical values were obtained from 50 healthy bonnet macaques of both sexes and aged 10–234 months. Results Age and sex differences were present in a number of measures. Globulins, total protein, and creatinine (CREAT) values were highest among older subjects, while alkaline phophatase, albumin, and phosphorus values were higher in juveniles. Sex differences were present in concentrations of red blood cells and CREAT, with higher values in males. Conclusion The blood parameter data reported here as age‐specific reference values for laboratory‐housed, healthy bonnet macaques may be used to inform clinical care and laboratory primate research.