This is a lowland bird, a typical "Chaco bird", with a characteristic appearance and a remarkable nest. In Spanish, it is called 'Espinero crestudo,' roughly "crested thorn-worker," which I think is well illustrated by this picture of a couple, sitting on their mighty nest, built of surprisingly long and thorny branches. Even at a distance, one can discern the white patch around the eye, lined with dark brown and black, and the black crest, features that makes it different from all other birds in the area.