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Résumé :
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The foraging behavior and resource use of four syntopic species of antwrens (Drymophila) was studied at Intervales State Park (24 degrees 17'S, 48 degrees 25'W) in the southeastern Brazilian Atlantic forest. Ochre-rumped Antbirds (D. ochropyga) foraged mainly by probing for arthropods in dead leaves. The Ferrugineous Antbird (D. ferruginea) and Bertoni's Antbird (D. rubricollis) gleaned or sallied for insects mainly on live foliage in bamboo tickets. Dusky-tailed Antbirds (D. malura) used many kinds of substrate such as live leaves, dead leaves or twigs, and tended to hang while gleaning insects from herbaceous vegetation. Foraging speed during prey search was significantly slower for D. ochropyga, whereas differences in attack rate among other species were not significant. Niche overlap was measured for 11 substrate-maneuver combinations; D. ferruginea and D. rubricollis had large overlap (82%). Sympatric and syntopic coexistence of these four antwrens may be maintained by habitat and substrate specialization through exploitation of dead leaves and bamboo thickets.
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