These photographs were taken at the Ecotropical Field Station, about 40 km east of Palmas in Tocantins State, Brazil. Altitude 750m. They were in gallery forest in an area that is mainly cerrado savanna.
On range alone they are most likely to yellow-throated woodpeckers, but there is enough variance with the field guides and photos I've seen to make me ask for opinions on their identification from this forum. Especially as the throat on one bird looks clean white, while on neither was the face plain yellow - there is a lot of green on the ear coverts.
Thanks in advance!