Following on from the productive discussion about my photo of white-throated woodpecker, here is another picture from the same site - the Ecotropical Field Station, near Palmas, in Tocantins (10° 16' 47" S, 48° 9' 35" W). This small seed-eating bird was with two fledglings in bamboo at the top of a valley, near the transition between gallery forest and open cerrado. No accompanying males I'm afraid (assuming that this is female). I would greatly appreciate any thoughts about its ID.
Given the quality of the photo I'm not expecting great things, but then again there are some very sharp birders who read these posts...