The purpose of this volume is to present a comprehensive overview of recent advances in primate field research, ecology, and conservation biology in Mesoamerica. The overall goal of each contribution is to integrate newly collected field data with theoretical perspectives drawn from evolutionary biology, socioecology, biological anthropology, and conservation to identify how our current knowledge of primate behavior and ecology has moved beyond more traditional approaches. A corollary to this, and an important goal of the volume is to identify geographical regions and species for which we continue to lack sufficient information, to develop action plans for future research, and to identify areas for immediate conservation action. Despite many decades of primate research in Mesoamerica, much is still unknown concerning the basic ecology and behavior of these species, demography, current distribution, and conservation status of local populations, and the effectiveness of conservation policies on primate survivorship. Four major areas of research are the focus of the volume: Evolutionary Biology and Biogeography; Population Demography and Ecology; Behavior; and Conservation and Management Policies.

A wide variety of plants, ranging in size from forest floor herbs to giant canopy trees, rely on animals to disperse their seeds. Typical values of the proportion of tropical vascular plants that produce fleshy fruits and have animal-dispersed seeds range from 50-90%, depending on habitat. In this section, the authors discuss this mutualism from the plant's perspective. Herrera begins by challenging the notion that plant traits traditionally interpreted as being the product of fruit-frugivore coevolution really are the outcome of a response-counter-response kind of evolutionary process. He uses examples of congeneric plants living in very different biotic and abiotic environments and whose fossilizable characteristics have not changed over long periods of time to argue that there exists little or no basis for assuming that gradualistic change and environmental tracking characterizes the interactions between plants and their vertebrate seed dispersers. A common theme that runs through the papers by Herrera, Denslow et at. , and Stiles and White is the importance of the 'fruiting environment' (i. e. the spatial relationships of conspecific and non-conspecific fruiting plants) on rates of fruit removal and patterns of seed rain. Herrera and Denslow et at. point out that this environment is largely outside the control of individual plant species and, as a result, closely coevolved interactions between vertebrates and plants are unlikely to evolve.

This will be the first time a volume will be compiled focusing on South American monkeys as models to address and test critical issues in the study of nonhuman primates. In addition, the volume will serve an important compliment to the book on Mesoamerican primates recently published in the series under the DIPR book series. The book will be of interest to a broad range of scientists in various disciplines, ranging from primatology, to animal behavior, animal ecology, conservation biology, veterinary science, animal husbandry, anthropology, and natural resource management. Moreover, although the volume will highlight South American primates, chapters will not simply review particular taxa or topics. Rather the focus of each chapter is to examine the nature and range of primate responses to changes in their ecological and social environments, and to use data on South American monkeys to address critical theoretical questions in the study of primate behavior, ecology, and conservation. Thus, we anticipate that the volume will be widely read by a broad range of students and researchers interested in prosimians, New World monkeys, Old World monkeys, apes, humans, as well as animal behavior and tropical biology.

The purpose of this volume is to present a comprehensive overview of recent advances in primate field research, ecology, and conservation biology in Mesoamerica. The overall goal of each contribution is to integrate newly collected field data with theoretical perspectives drawn from evolutionary biology, socioecology, biological anthropology, and conservation to identify how our current knowledge of primate behavior and ecology has moved beyond more traditional approaches. A corollary to this, and an important goal of the volume is to identify geographical regions and species for which we continue to lack sufficient information, to develop action plans for future research, and to identify areas for immediate conservation action. Despite many decades of primate research in Mesoamerica, much is still unknown concerning the basic ecology and behavior of these species, demography, current distribution, and conservation status of local populations, and the effectiveness of conservation policies on primate survivorship. Four major areas of research are the focus of the volume: Evolutionary Biology and Biogeography; Population Demography and Ecology; Behavior; and Conservation and Management Policies.

Any scientific discipline needs a theoretical framework to guide its development and to sharpen the questions its researchers pursue. In biology, evolution is the grand theoretical framework, and an his torical perspective is necessary to understand present-day biological conditions. In its formative years, the modern study of the fruit-frugivore mutualism was guided by the 'specialist-generalist' paradigm developed by D. Snow, D. McKey, and H. Howe. Howe reviews the current status of this evolution ary paradigm and points out that it has been dismissed by many workers before being adequately tested. This is because ecologists working with the tropical plants and frugivorous birds for which the paradigm was originally developed rarely measure the seed dispersal effectiveness of different disperser species. He indicates that this paradigm still has heuristic value and suggests that several additional ecological paradigms, including the concept ofkeystone species ofplants and frugivores and the role that frugivores play in density-dependent mortality in tropical trees, are worth studying. The concept of seed dispersal quality has been central to discussions of fruit-frugivore coevolution. Schupp thoroughly reviews data bearing on this concept, constructs a hierarchical framework for viewing disperser effectiveness, and points out that disperser effectiveness depends on both the quantity and quality of seed dispersal. Effectiveness, in turn, affects both evolutionary and ecological relationships between dispersers and their food plants."

A wide variety of plants, ranging in size from forest floor herbs to giant canopy trees, rely on animals to disperse their seeds. Typical values of the proportion of tropical vascular plants that produce fleshy fruits and have animal-dispersed seeds range from 50-90%, depending on habitat. In this section, the authors discuss this mutualism from the plant's perspective. Herrera begins by challenging the notion that plant traits traditionally interpreted as being the product of fruit-frugivore coevolution really are the outcome of a response-counter-response kind of evolutionary process. He uses examples of congeneric plants living in very different biotic and abiotic environments and whose fossilizable characteristics have not changed over long periods of time to argue that there exists little or no basis for assuming that gradualistic change and environmental tracking characterizes the interactions between plants and their vertebrate seed dispersers. A common theme that runs through the papers by Herrera, Denslow et at. , and Stiles and White is the importance of the 'fruiting environment' (i. e. the spatial relationships of conspecific and non-conspecific fruiting plants) on rates of fruit removal and patterns of seed rain. Herrera and Denslow et at. point out that this environment is largely outside the control of individual plant species and, as a result, closely coevolved interactions between vertebrates and plants are unlikely to evolve.