Southern Beardless-Tyrannulet Camptostoma obsoletum

Small flycatcher, common and widespread from Costa Rica to Argentina. Plumage is nondescript (and quite variable across range), but note bushy crest, active behavior, short bill, and plain face. Singles, pairs, or small groups can be found in a variety of wooded habitats, from dry scrub to the edge of mature rainforest, but often prefers second growth. Voice varies across range, with different populations probably representing separate species. Northern birds give plaintive whistled “teew, teew, teew” notes. Southern birds can give much different descending sputtering trill in addition to plaintive whistles.