Temporal habitat variations can affect the trophic relationships of amphibian species by changing either prey availability or predator selectivity. This study aimed to evaluate the influence of prey availability and temperature variation on the diet of three anuran species (Boana pulchella, Odontophrynus maisuma, and Leptodactylus latrans) in subtropical swamps. Coleoptera, Araneae, Diptera, and Hymenoptera were the most important prey. Trophic niche overlap was greatest between Odontophrynus maisuma and B. pulchella. In the warmer months, all three species narrowed their trophic niches by increasing the consumption of certain prey. The changes recorded in the diet might be related to variations in prey availability and other aspects of feeding ecology, such as adaptations in foraging activity, and show that these species have some plasticity regarding their feeding habits.