Primate Communities: Past, Present, and Possible Future Kaye E. Reed 1,2 * and Laura R. Bidner 1 1 Department of Anthropology, Arizona State University, Tempe, Arizona 85287 2 Institute of Human Origins, Arizona State University, Tempe, Arizona 85287 KEY WORDS community ecology; primate evolution; biogeography; community conservation ABSTRACT An understanding of the fundamental causes of the structure of primate communities is impor- tant for studies of primate evolutionary history, primate behavioral ecology, and development of conservation strategies. Research into these structuring factors has benefited from new perspectives such as consideration of primate phylogenetic history, metacommunities, and in- teractions with predators and nonprimate competitors. This review presents the underlying factors of primate community structure within the biogeographic regions of Madagascar, the Neotropics, Africa, and Asia. One of the major differences among these locations likely resulted from the initial primate taxa that colonized each region (a single colonization event in the case of Madagascar and South America, and multiple radiations of higher-level taxa in Africa and Asia). As most primates live in forests, the differences among the forests in these locations, caused by various climatic influences, further influenced speciation and the development of primate communities. Within these habitats, species interactions with different groups of organisms were also instrumental in developing community dynamics. Through an investigation of these fundamental factors, we identify some of the most impor- tant effects on primate communities in each region. These findings suggest that low primate richness in Asia may be caused by either the abundance of dipterocarp trees or high levels of monsoon rains. High numbers of frugivores and a lack of folivores in neotropical communities may be associated with competiton with sloths that were already present at the time of initial radiation. Climatic patterns which affect forest structure and productivity in Madagas- car may be responsible for high numbers of folivorous lemurs. The identification of these factors are important for the conservation of existing primate communities, and indicate directions for future studies. Yrbk Phys An- thropol 47:2–39, 2004. © 2004 Wiley-Liss, Inc. A primate community can be loosely defined as all primate species that live together and utilize re- sources at one geographic location. Each community can also be viewed as the end result of one or more adaptive radiations. That is, ancestral primates have colonized each continent and undergone sub- sequent species diversification with regard to re- source partitioning. As such, comparisons of extant primate communities offer insights into how differ- ent evolutionary histories, habitats, and species in- teractions shaped primate evolution in particular regions. The understanding of how primates mi- grated, evolved, and currently exist together is also important for planning conservation strategies for their diminishing habitats. Prior studies led re- searchers to hypotheses about why there are major differences among primate communities on different continents. Our goal is to review the causes associ- ated with these questions and outline possible an- swers: What are the major causes of differences among primate communities? Why is Asia charac- terized by low primate species richness? What is the reason for the species density and low adaptive di- versity of primates in neotropical communities? Why is there a bias toward folivorous primates in Madagascar? Is there a trade-off between frugivore richness and population densities in Africa and the Neotropics? In this paper, we begin by summarizing some of the proposed reasons for the development and main- tenance of community structure. We refer to struc- ture as the different patterns with which commu- nities can be identified, such as taxonomic composi- tion, species diversity, ecological diversity and adaptations, and species interactions (Morin, 1999). For example, the pattern of ecological diversity in a primate community may consist of contrasting diets, activity patterns, substrate use, and body size of member species, while a species diversity pattern may indicate population dynamics of the resident primates defining dominant vs. rare species. Either of these patterns is representative of the structure of *Correspondence to: Kaye Reed, Institute of Human Origins, Arizona State University, Box 874101, Tempe, AZ 85287-4101. E-mail: kaye.reed@asu.edu DOI 10.1002/ajpa.20153 Published online in Wiley InterScience (www.interscience.wiley. com). YEARBOOK OF PHYSICAL ANTHROPOLOGY 47:2–39 (2004) © 2004 WILEY-LISS, INC.