The top bird is is probably a male. Females usually have no red on their head. This small woodpecker preferred to forage in vines where it was difficult to see. It is widespread but locally distributed in Eastern South America. It superficially resembles woodpeckers in the genus Picoides, but is now placed in Veniliornis based on genetic studies. See SACC Proposal 262 for details. Four subspecies are recognized. This is one of the two southern races. Birds in this group are less buffy and have more white on their back. Nominate mixtus meets berlepschi in Buenos Aires with the latter being found to the south. This individual's location appears to be in the intergrade zone between them.
Digiscoped with Panasonic DMC-LX5 | Nikon FieldScope III | 30XWA | hand-held (no adapter)