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.

Evolutionary and Ecological Implications of Primate Seed Dispersal

Abstract: In this paper, we evaluate patterns of fruit eating and seed dispersal in monkeys and apes and draw an important distinction between 1) the ecological consequences of primates as seed dispersers and 2) the evolutionary implications of primates on the seed and fruit traits of the plant species they exploit. In many forest communities, primates act as both seed predators and seed dispersers and are likely to have an important ecological impact on patterns of forest regeneration and tree species diversity. Evidence from Kibale National Park, Uganda, and Manu National Park, Peru, as well as several other South American sites indicates that monkeys and apes display a wide range of fruit-processing behaviors, including spitting seeds, dropping seeds, masticating seeds, and swallowing seeds. Differences in consumer body size, diet, ranging patterns, and oral and digestive morphology result in different patterns in the distance and distribution of seeds from the parent plant. In the case of South American monkeys, for example, despite their relatively small body size, platyrrhines were found to exploit larger fruits and swallow larger seeds on average than did Old World monkeys and apes of the Kibale forest. We found little evidence to support the existence of a coevolutionary relationship between a single or set of primate dispersers and the particular plant species they disperse. This is due to variability in the manner in which monkeys and apes select fruits and treat seeds, the fact that many species of primates and nonprimates exploit and disperse the same fruit species, and the fact that extremely high levels of postdispersal seed, seedling, and sapling mortality serve to dilute the influence that any primate species may have on the recruitment of the next generation of adult trees. It is apparent that many primate lineages exhibit dental, digestive, and/or sensory adaptations that aid in the exploitation of particular food types and that many lineages of flowering plants have evolved characteristics of fruits and seeds that facilitate seed dispersal. However, in light of currently available data, we argue that these represent evolutionary rather than more strictly defined coevolutionary relationships.

Effects of aging on the primate visual system: spatial and temporal processing by lateral geniculate neurons in young adult and old rhesus monkeys.

Abstract: 1. Visual abilities decline during normal aging, and many of these declines are due to neural changes in the retina or central visual pathways. We have begun studies of the primate visual system to...

Dispersal patterns in sympatric woolly and spider monkeys: integrating molecular and observational data

Abstract: Dispersal is a behavioral process that shuffles genes across the physical and social landscapes. Analysis of how genetic variation is structured hierarchically and among males versus females can provide insights into underlying dispersal processes, even when direct observations of dispersal events are lacking, but application of these techniques in primate studies has been limited. We investigated dispersal patterns in two South American primates — woolly and spider monkeys — using a combination of multilocus genotype data from > 150 animals sampled at two sites in Amazonian Ecuador and opportunistic field observations that shed light on likely dispersal events. Molecular analyses revealed considerable gene flow by females, but substantial male-mediated gene flow was also detected, particularly for woolly monkeys. In both taxa, the extent of population differentiation between the two study sites was greater for males than for females, indicating that gene flow by males has been more restricted historically. Additionally, in one group of spider monkeys, the average relatedness among adult males was significantly greater than that among females, consistent with strong male philopatry, and assignment tests for that group likewise suggest female-biased dispersal. However, for another group of spider monkeys — and for all groups of woolly monkey surveyed — these patterns were not observed. Our molecular results are concordant with field observations of immigrations by female spider monkeys, disappearances (likely emigrations) involving females of both species, and multiple sightings of solitary males and small bachelor groups in woolly monkeys, as well as with the specific dispersal histories of a few woolly monkey individuals discernable through longitudinal molecular sampling. Overall, the results demonstrate the utility of molecular approaches to studying dispersal in primates as a complement to observational studies, but also suggest that further evaluation of dispersal patterns among these primates is needed.