Primate

About: Primate is a research topic. Over the lifetime, 1250 publications have been published within this topic receiving 67388 citations. The topic is also known as: the primate order & primates.

New World Primate Field Studies: What's in it for Anthropology?

Abstract: The living New World or neotropical primates, infraorder Platyrrhini or Superfamily Ceboidea, range from about 24?N. in Tamaulipas, Mexico (spider and howler monkeys) to about 30?S. in Rio Grande do Sul, Brazil (howlers) (167). Fossil platyrrhines have been found near the southern tip of South America in Santa Cruz, Argentina (197), but they are not known to have ranged farther north than they do today. They moved into Central America only after establishment of the Panamanian land bridge in the Late Miocene to Early Pliocene, 5-6 million years ago (235). The platyrrhines are found primarily in forested habitats, including both dry forest and rain forest, up to 3200 m elevation (night monkeys and howler monkeys) (94). Although they do not occur on open savanna as do Old World baboons and patas monkeys, howlers and marmosets and perhaps others do occur in open scrub and sparsely wooded or low canopied dry woodlandllanos (Colombia and Venezuela), cerrado (Brazil), pampas (Argentina), or chaco (Bolivia and Paraguay). All platyrrhines are diurnal except the night monkey Aotus. They range in size from the pygmy marmoset (100-120 g adult body size) to the woolly spider monkey or muriqui which weighs up to 15 kg. There are disagreements at many levels about the taxonomy of the Platyrrhini. This is not the place to discuss these problems, but recognizing the controversies, I have adopted a distillation of two modern classifications, by Rosenberger (201) and by Ford (72), as presented in Table 1. For consistency all discussions in this chapter refer to this classification. A recent alternative

Subtoxic Hepatic Vitamin A Concentrations in Captive Rhesus Monkeys (Macaca mulatta)

Abstract: Although the rhesus monkey (Macaca mulatta) is a widely used experimental animal, its exact vitamin A requirement is unknown. An amount of 430-3600 IU/d [129-1080 retinol equivalents (RE)] is recommended, largely on the basis of depletion studies. Normal hepatic vitamin A appears to be 1 micromol/g liver. Our goal was to determine hepatic vitamin A concentrations of captive monkeys. Liver autopsy samples from rhesus and marmoset (Callithrix jacchus) monkeys were obtained from the Wisconsin Regional Primate Research Center. The rhesus monkeys consumed a diet with 40 IU (12 RE) retinyl acetate/g. Male and female monkeys consumed an estimated 250 and 175 g diet/d, respectively. Marmosets were fed a powder-based diet consisting of 20 IU (6 RE) retinyl acetate/g. The marmosets consumed an estimated 25 g of the diet/d. Liver samples were extracted and analyzed by HPLC. The vitamin A concentration of the rhesus monkey livers was very high at 17.0 +/- 6.3 micromol/g. The hepatic vitamin A of the marmosets was 1.25 +/- 0.58 micromol/g liver. Histologic examination of the livers revealed Ito cell hypertrophy and hyperplasia in the rhesus monkeys compared with the marmosets. Considering that the natural diet of the rhesus monkey (fruits, seeds, roots and insects) is not high in preformed vitamin A, the vitamin A content of the diet appears excessive, supplying four times the NRC recommendation and resulting in high liver stores.

Interactions of Howler Monkeys with Other Vertebrates: A Review

Abstract: Understanding the way howler monkeys interact with other vertebrates has critical ecological, evolutionary, cognitive, and conservation implications. In this review, we completed an extensive search of the available data on interspecific howler encounters, including individual communications from field primatologists, in order to gain insight into how howlers share their habitat and interact with other species, the pressure that predators and potential competitors may exert on them, and the potential benefits and costs that howlers may represent for other species. Howlers interacted with several vertebrates throughout their distribution range, including birds and mammals, particularly capuchin monkeys, spider monkeys, and coatis. A great deal of these interactions occurred in fruiting trees and were, in general, pacific, although howlers were frequently harassed by other monkeys, and they were observed behaving aggressively with coatis and birds. Howlers were also targets of multiple predators. Among them, large felids and harpy eagles are ranked as the prevalent natural predators of this primate taxon. Finally, evidence indicates that the transformation of natural habitats can have important effects on the interaction patterns of howlers with other species. Fragmentation can increase competition for food and in extreme cases even force them to predate on eggs to compensate for the reduction in food availability. On the other hand, natural predators are often absent in anthropogenic landscapes, but there are increasing reports of predation by dogs and coyotes, which could potentially have very negative effects on the already highly threatened populations of howler monkeys in fragmented landscapes.

Neurochemical organization of the vestibular brainstem in the common chimpanzee (Pan troglodytes).

Abstract: Chimpanzees are one of the closest living relatives of humans. However, the cognitive and motor abilities of chimpanzees and humans are quite different. The fact that humans are habitually bipedal and chimpanzees are not implies different uses of vestibular information in the control of posture and balance. Furthermore, bipedal locomotion permits the development of fine motor skills of the hand and tool use in humans, suggesting differences between species in the structures and circuitry for manual control. Much motor behavior is mediated via cerebro-cerebellar circuits that depend on brainstem relays. In this study, we investigated the organization of the vestibular brainstem in chimpanzees to gain insight into whether these structures differ in their anatomy from humans. We identified the four nuclei of vestibular nuclear complex in the chimpanzee and also looked at several other precerebellar structures. The size and arrangement of some of these nuclei differed between chimpanzees and humans, and also displayed considerable inter-individual variation. We identified regions within the cytoarchitectonically defined medial vestibular nucleus visualized by immunoreactivity to the calcium-binding proteins calretinin and calbindin as previously shown in other species including human. We have found that the nucleus paramedianus dorsalis, which is identified in the human but not in macaque monkeys, is present in the chimpanzee brainstem. However, the arcuate nucleus, which is present in humans, was not found in chimpanzees. The present study reveals major differences in the organization of the vestibular brainstem among Old World anthropoid primate species. Furthermore, in chimpanzees, as well as humans, there is individual variability in the organization of brainstem nuclei.