White-lipped peccaries (Tayassu pecari, Tayassuidae, Cetartiodactyla), forest-dwelling ungulates ranging from Central to South America, aid in maintaining healthy Neotropical forest ecosystems through key aspects of their dietary behaviors, including seed predation and dispersal. However, land-use change and deforestation threaten access of white-lipped peccaries to food resources, and thus knowledge of if and how their diet varies spatially is necessary to frame conservation efforts for the species. Here, we use stable carbon (δ13C) and nitrogen (δ15N) isotopes from white-lipped peccary hair and food resources to assess whether diets of white-lipped peccaries vary among four regions in three Brazilian biomes each varying in forest canopy cover, climatic characteristics, and degree of agricultural impacts: (i) the Pantanal, a seasonally inundated wetland that is somewhat fragmented for cattle-ranching; (ii) the Cerrado, a forest experiencing distinct wet and dry seasons and also fragmented mainly as a result of cattle-ranching; (iii) the semi-deciduous Atlantic Forest, an interior forest experiencing seasonal weather patterns that is heavily fragmented as a result of agriculture ; and (iv) the ombrophilous Atlantic Forest, a dense, tropical, humid coastal rainforest with well-connected tracts of undisturbed forest.
Results/Conclusions
We find that in all regions white-lipped peccaries are consuming primarily C3 forest resources, with mean δ13C values ranging from –28.7‰ to –26.9‰. In the heavily fragmented semi-deciduous Atlantic Forest, δ13C values are the highest, and may indicate that some individuals are consuming a small amount of C4 crops or demonstrating increased levels of insectivory. A through-time comparison of white-lipped peccary hair in the semi-deciduous Atlantic Forest suggests the recorded slight departure from an exclusive C3 diet may be a recent phenomenon, as hairs collected prior to the year 2000 have lower δ13C values than those collected in 2016. While some individual white-lipped peccaries may slightly alter their diet in heavily anthropogenically modified areas, C4 crops are not a main component of the diet of white-lipped peccaries. Our results suggest that white-lipped peccaries are still highly dependent on forest resources, even in human-altered landscapes, and conservation and management plans for the species must consider these dietary needs to be successful.