Aim. A primary goal of community ecology is to understand the mechanisms that drive species’ spatial distribution and habitat associations. Species' geographic distribution can be influenced by the distribution of their prey partly because consumers' behavior is oriented to optimal energy use during foraging. We analyzed how differences in dietary preferences influence the spatial distribution and habitat associations of species at the landscape scale. We hypothesized that differences in feeding guilds will lead to divergent habitat association patterns among species.

Location. Amazon River drainage basin. 

Taxon. Characiform fishes in the family Serrasalmidae (piranhas and pacus). 

Methods. We used diet data to classify species into feeding guilds (frugivores, herbivores, piscivores, fin and scale feeders, and planktivores). We used three proxies of habitat association derived from satellite products: floodplain extent, landscape heterogeneity, and flood duration, in three distance buffers. We implemented Phylogenetic Generalized Least Squares models to evaluate the relationship between habitat association and feeding guilds.

Results. Frugivores, piscivores, and fin and scale feeders presented similar patterns of habitat associations, with frugivores occupying wider areas of floodplain and greater landscape heterogeneity. Herbivores and planktivores were associated with smaller floodplain extents and lower landscape heterogeneity. All feeding guilds were associated with similar levels of flood duration.

Main conclusions. Differences in resource distribution (assessed through feeding guilds) can influence habitat association.  Considering the hydrological variability (i.e., floodplain extent) and landscape heterogeneity that characterize floodplains, the patterns of habitat association vary with the spatial scale considered. This work highlights the importance of understanding species habitat associations by fish as well as food resource dynamics and floodplain dependence. This realization is critical for assessing the impact of anthropogenic activities on freshwater ecosystems.