Siamang Socioecology in Spatiotemporally Heterogenous Landscapes: Do “Typical” Groups Exist?

Abstract

Tropical rainforest habitats are the most biologically diverse and spatially heterogeneous landscapes on earth, including a bewildering variety of life forms organized into a complex three-dimensional lattice. Sumatran forests contain enormous numbers of plant species, some of which are present at low densities, and the dominant tree species vary with elevation, soil structure, other landscape features, and geographic region (Whitten et al. 2000). Natural and anthropogenic disturbances produce a diversity of microhabitats within each general habitat type. Plant dispersal dynamics, interactions among plant species or individuals within rainforest habitats, and plant-animal interactions may also result in uneven distributions of plants across space (Condit et al. 2000; Silva and Tabarelli 2001). Therefore, each unit of area in a rainforest habitat contains a set of plants that differs at least slightly from that in the adjacent area. Accordingly, for territorial animal species that utilize plant resources, the actual and relative availability of specific plant foods in a given month may vary substantially between territories, even among neighboring groups.