Body mass ratios determine dietary patterns and help predicting predator–prey interactions of Neotropical Carnivora

Mammalian carnivores are particularly relevant for ecosystem functioning, but for many Neotropical species, dietary information is scarce or unevenly sampled across their distribution. Understanding the influence of predator–prey body mass relationships on species’ diets offers an opportunity to predict the interactions taking place in real food webs and estimate the most likely interactions to take place in undersampled areas. We compiled quantitative data on the diets of 12 Neotropical species of Carnivora from 99 studies and investigated the performance of statistical models in estimating their dietary patterns using predator–prey body mass ratios as predictors. We fitted models at three levels: order; non-felids and felids; predator species. The consumption patterns of prey species were highly variable according to the body mass of predators, but we found a general consistency across species, with prey consumed more frequently usually having less than 5% of the body mass of the predator. Although our analysis suggests an overall pattern on the relationship between the body mass of predators and their prey, the predictive power of the model increased considerably when considering predator group (felid and non-felid) or species. This highlights that accounting for the variation in resource-use patterns between species improves the predictability of interaction patterns. Models using predator–prey body mass ratios as predictors can be useful to infer trophic interactions, providing a baseline estimation of the relative frequency of consumption of different prey by predators. This information is essential to plan and assess the outcomes of conservation initiatives aimed at maintaining predators and prey populations, ecosystem health, and prevention of human-wildlife conflicts.