Fig. 1.

Hypotheses of resource use and trophic structure. Regarding resource use, the reduction in forest cover causes a transition in the use of resources by mammals between preserved areas (predominantly C₃) and HMLs (predominantly C₄). Regarding trophic structure, in preserved areas, with more complete assemblages than HMLs, the trophic structure is more complex, and there is a stepwise increase in δ¹⁵N values from herbivores to carnivores. In HMLs, due to species loss and turnover in combination with the presence of agricultural matrices, which offers nitrogen-enriched food items, δ¹⁵N values fluctuate among trophic guilds, resulting in a modified trophic structure.