Aggregated seed dispersal by spider monkeys limits recruitment to clumped patterns in Virola calophylla

tion in seed density generated by dispersal agents, par-ticularly in forest communities. An increasing number of studies has revealed patterns of seed deposition in forests either by using seed traps and inverse model-ling or by developing mechanistic models of the be-havior of dispersal agents to simulate seed dispersion (Nathan & Muller-Landau 2000). These studies sug-gest that seed deposition is often spatially aggregated, particularly for vertebrate-dispersed tree species (Sch-upp et al. 2002). Second, the spatial pattern of seed deposition and the recruitment consequences of that pattern affect the den-sity and dispersion of plants in later life stages (Hubbell 1980; McCanny 1985). One mechanism that has figured prominently in explaining tree dispersion, particular-ly in tropical forests (Hubbell 1980; Augspurger 1983a; Clark & Clark 1984; Condit et al. 1992), is survival that depends upon the density of seeds, seedlings, and/ or saplings or their distance from a conspecific adult (Janzen 1970; Connell 1971). Such non-random surviv-al resulting from natural enemies, such as seed preda-tors and seedling pathogens, can thin clumps of seeds and seedlings and produce spatial patterns that dif-fer from what would result simply from random thin