Dieta e comportamento de forrageamento de Suiriri affinis e S. islerorum (Aves, Tyrannidae) em um cerrado do Brasil central

摘要

The foraging behavior of Suiriri affinis (Campo Suiriri) and S. islerorum (Chapada Flycatcher), two sintopic Tyrant Flycatchers in the Central Brazilian Cerrado (tropical savanna) was studied. During 2003, 188 feeding bouts of S. affinis and 150 of S. islerorum were registered. Differences between the two species in the feeding height, foraging substrate, phytophysiognomy used, and foliage density at the point of foraging observation were found. The attack methods, attack direction, distance of flight, and plant species used did not differ between both species. The analysis of 26 stomach contents of members of this genus revealed only arthropods. The low percentage of feeding bouts directed to fruits (only 7% and 9%, respectively) confirmed the insectivorous character of this genus.