Some tree species exhibit large year-to-year variation in seed production, a phenomenon known as masting (Kelly 1994, Kelly & Sork 2002). Even in tropical rain forests, in which the climate is suitable for plant growth all year round with little seasonal variation (Whitmore 1998), there are many reports of masting (Appanah 1993, Hart 1995, Newbery et al. 1998, Newstrom et al. 1994, Wheelwright 1986). In particular, Dipterocarpaceae, the dominant family in lowland mixed dipterocarp forests in South-East Asia, undergo mast fruiting following mass-flowering with strong interspecific synchronization in aseasonal western Malesia (Appanah 1985, 1993; Ashton 1989, Ashton et al. 1988, Curran et al. 1999, Janzen 1974, Medway 1972, Sakai et al. 1999, Whitmore 1998, Wood 1956). In mixed-dipterocarp forests, dipterocarp species contribute more than 70% of the canopy biomass (Bruenig 1996, Curran & Leighton 2000). Masting of dipterocarp species is therefore likely to have a major impact on animal populations, and also on the nutrient cycle in such forest ecosystems by causing fluctuations in the availability of resources (Sakai 2002).

Many frugivorous animals disperse seeds in their faeces (Corlett 1998, van der Pijl 1982), which may enhance the ability of secondary seed dispersers and post-dispersal seed predators to locate seeds (Andresen 2001, Chapman 1989, Feer 1999, Janzen 1982). By destroying and moving seeds these animals can radically alter the primary seed shadows generated by frugivorous animals and, consequently, have the potential to influence plant recruitment (Alcántara et al. 2000, Crawley 1992). Nevertheless, the influence of faeces on seed removal in South-East Asian forests has not previously been investigated and our knowledge currently comes from studies in Neotropical forests (Andresen 2001, Chapman 1989, Feer 1999, Janzen 1982).

Although highly diverse (Fonseca et al. 1996), the Atlantic forest mammal fauna is still poorly known, with very few sites exhaustively inventoried or subjected to long-term studies (Passamani et al. 2000). Although the first surveys using camera traps were carried out in the 1920s (e.g. Chapman 1927), most studies are rather recent (Karanth & Nichols 1998). This is not different in Brazil, where few studies have been published (Marques & Ramos 2001, Santos-Filho & Silva 2002, Silveira et al. 2003, Trolle 2003, Trolle & Kéry 2003). Given this, the objective of this paper is to assess the efficiency of camera trapping as an inventory technique for Neotropical forests in general and Atlantic forest in particular. The study was conducted at the Santa Lúcia Biological Station (SLBS), a biologically rich Atlantic Forest preserve located in south-eastern Brazil (Mendes & Padovan 2000) where mammals have been intensively live-trapped, observed from line-transects or had indirect evidence of their presence (faeces, footprints, scratches, etc.) recorded in earlier years (Passamani et al. 2000).

An estimated 154 million ha of tropical forest are cleared each year by human activities such as cattle ranching and agriculture (Whitmore 1997). When the economic return of these sites declines, they are often abandoned and allowed to regenerate. As a result, ‘secondary’ or ‘regenerating’ forests are becoming an increasingly common feature in tropical landscapes (Guariguata & Ostertag 2001). Unlike treefall gaps and other ‘naturally’ disturbed areas, the regeneration of secondary forests on anthropogenically disturbed lands does not always follow a predictable pathway (reviewed in Guariguata & Ostertag 2001). Instead, the type and intensity of post-clearing land use has major implications for the trajectory along which succession proceeds (Guariguata & Ostertag 2001, Mesquita et al. 2001, Uhl et al. 1988).