Showing papers on "Primate published in 1989"

The special role of male Cebus monkeys in predation avoidance and its effect on group composition

Abstract: Vigilance behavior, predator detection abilities, and responses to real and model predators were studied in two species of capuchin monkeys (Cebus albifrons and C. apella) in a Peruvian lowland rain forest. Adult males were more vigilant than adult females in both species, mainly because the males spent less time feeding and foraging and partly because they were at the periphery more often than the females. The increased vigilance of adult males is reflected in their superior performance in the detection of (model) predators. Adult and subadult males were also far more likely to approach and mob real and model predators. Adults that were outside the center of the group increased foraging activities but cut back an feeding, much of which was done in exposed tree crowns. Current theory suggests that primate groups are multi-male when a single male is unable to defend sexual access to the group of females. In these small capuchin groups, which are multimale, the enhanced safety of females and young provided by extra adult males furnishes a more plausible explanation. A comparison of the two capuchins with the ecologically similar Southeast Asian Macaca fascicularis suggests that the high predation risk outside the group may also have caused the unusual male career profile in capuchins, which have a long tenure of dominants and a very long potential lifespan. Further predictions of this hypothesis are developed.

Influence of early rearing on lymphocyte proliferation responses in juvenile rhesus monkeys.

Abstract: Lymphocyte proliferation responses and natural killer cell activity were evaluated in 35 juvenile rhesus monkeys derived from five different rearing conditions. Nursery-reared monkeys had proliferation responses which were significantly higher than those of mother-reared subjects. Reexamination of the nursery-reared monkeys 1.5 years later indicated that an abnormally high response to concanavalin A was still evident at 2.5 years of age, but both PHA and PWM responses had shown an age-appropriate decrease into the normal range for this species. Proliferation responses in monkeys that had been weaned early from their mothers at 6 months of age were also higher than values for control monkeys that remained with their mothers, but below those of the nursery-reared monkeys. In contrast, monkeys that had received multiple separations from the mother between 3 and 7 months of age showed lymphocyte proliferation responses that were below normal. These results indicate that early rearing conditions can have a lasting effect on certain immune responses in the developing primate.

Activity budget and diet of patas monkeys in Kala Maloue National Park, Cameroon: A preliminary report

Abstract: A preliminary study was carried out on the feeding ecology of patas monkeys in the rainy season in Cameroon. Their daily activity rhythm revealed two active peaks. The proportion of time spent on feeding with respect to waking time was 30%. Patas monkeys largely depended on the flowers and buds of herbaceous plants and the larvae of insects for their diet as they ranged widely. Patas monkeys spent more time in feeding and travelled for a longer distance per day than the sympatric primate species, the tantalus monkey. It is considered that these findings reflected the large amount of food requirement due to the large body size, as well as the low density and high degree of dispersal of their food.

Studies of free-ranging and corralled patas monkeys at La Parguera, Puerto Rico.

Abstract: Patas monkeys (Erythrocebus patas) were maintained and studied at the La Parguera primate colony between 1971 and 1982. This paper describes the founding of the patas population, its growth, and its eventual termination. The behavioral and biological studies conducted on the La Parguera patas monkeys are also described.

Pathologic and virologic description of three cases of type D retrovirus infection in rhesus monkeys and a brief review of nonhuman primate retroviruses

Abstract: Recently, three Macaca mulatta monkeys at the Wisconsin Regional Primate Research Center developed diseases that fit into the simian acquired immune deficiency syndrome (SAIDS). The purpose of this report is to describe the disease manifestations seen in these rhesus monkeys. Additionally, a brief review of primate retroviruses is given.

Transplantation of fetal neocortex in rhesus monkey

Abstract: A feasibility study of neural transplantation in adult rhesus monkey was undertaken. Fresh and preserved neocortex containing multiplying and maturing neurons obtained from 55–70 gestation days were transplanted into the striatum, cerebellum and cerebral cortex of adult monkeys. Tissues were preserved for 4 days either at subzero temperature in the freezer compartment of the ordinary refrigerator in Ringer lactate or incubated in culture medium. While 2 monkeys out of 5 injected with preserved tissue had successful transplants after 4 months, all the 10 monkeys injected with fresh tissue had no transplants. The size of the two surviving transplants was small. The neurons in the transplants were mainly in clusters. Many of the cells were immature and some showed early degenerative changes. Neuronal processes were restricted to the transplants and thus showed lack of morphological integration with the host tissue. Further studies are in progress to define the nature of the embryonic tissue of primate which can grow and survive and also the role of neural grafts in functional recovery following experimental lesions of the brain regions.

A comparative review of the primate motor system.

Abstract: Primates have evolved separately from other mammals since the late Cretaceous, and during this time the two major extant primate groups, prosimians (lorises, lemurs, and tarsiers) and anthropoids (monkeys, apes, and humans) arose. Concurrently, structures within the central nervous system acquired primate characteristics. Not all of the uniquely primate features have been identified in the brain, but several are well known. The pyramidal system, the best studied motor system, shows a distinct primate pattern in its terminal connections in the spinal cord. Other descending systems are less well known, but primate specializations in the vestibular system and red nucleus have been observed. The primary and secondary motor cortices are topographically separated in primates, suggesting one basis for increased complexity. Given the size of the brain, structures in the basal ganglia are relatively enlarged in primates as compared with other mammals, whereas the cerebellum has the same relative size.

Pharmacological Probes in Primate Social Behavior

Abstract: The appropriateness of interaction with other individuals constitutes a significant factor in the determination of the diagnosis and treatment response in major psychiatric categories. Therefore, animal models of these disorders which include evaluation of social behavior add an important dimension to the model. Non-human primates have been used as subjects in most social studies because of their well documented social structure and noted behavioral similarities to humans.

On Female Primate Sexual Behaviour

Abstract: of foreign pathogens, the disruption of demographic, economic, and dietary patterns, the stress of acculturation, and the dependency created by inadequate services contribute to a decline in the level of health in the populations whose medical systems are the focus of ethnomedical studies (see Appell I980, Seijas and Arvelo-Jim6nez I978). In addition to its obvious interest for industrial societies, systematic understanding of traditional therapies and pharmacopoeias can contribute to the well-being of indigenous and peasant populations, instead of being expropriated from them, if it is incorporated into health, education, and environmental-planning policies for the regions they inhabit in such a way as to reinforce the use of proven therapies and medications and to preserve their cultural and natural sources. This ought not, of course, to exclude the improvement of medical-aid services or the use of therapies not yet proven. One might even contemplate cooperation between traditional and modern medical systems (see, e.g., Perrin and Uliyuu M. 1980). A methodology for the systematic cross-cultural study of the particular rationality of traditional medical systems and their diagnostic and therapeutic efficacy, both in their own terms (emic) and in terms of modern medical science (etic), would therefore represent an important contribution to this field. The methodology proposed by Browner et al. (CA 29:68i-89) generally pursues this objective, but it seems to me that the overemphasis on the physiological dimension and on the known biochemical activity of isolated substances limits its scope. The three procedures that constitute the method permit the determination of the emic coherence of diagnosis, etiology, physiological problems, and herbal medicines, their biomedical similarities and differences, and, to some extent, the efficacy of some medicinal plants. Insufficient attention is paid, however, to psychosocial factors, to the totality of the therapeutic action of herbs, and to therapies as wholes. In the case of susto, for example, the name of the illness (\"fright\"), the constancy of a central cluster of symptoms that are psychosomatic in nature, the variability of the organic symptomatology, and the social situation of the populations studied (not \"preindustrial\" but subordinated to industrial societies) suggest a strong etiological incidence of psychosocial factors, but these are here mentioned only tangentially as aggravating the organic pathologies. Furthermore, traditional therapies for susto are not mentioned. In the case of the herbal medicines, it is a pity that the criteria for empirical validation do not include the therapeutic effects observed in the field, doubtless recordable by researchers and rural physicians. Validation on the basis of substances previously isolated and tested clinically or in the laboratory obviously offers a high degree of confidence, but it presupposes that medical and pharmaceutical science has exhaustive knowledge of vegetable substances with desirable biochemical effects on humans. Finally, traditional therapies, especially in indigenous societies, often combine various medications, not all of them vegetable, and other therapeutic actions of a psychosocial or psychosomatic and/or physical nature (rites, chants, dances, massage, etc.), and this complexity is not here taken into account. The biochemical validation of medicinal herbs and the bioscientific verification of organic pathologies diagnosed in the terms of different cultures certainly constitute significant advances, but an important part of the medical systems under study remains in shadow.