
These are species with at least one recorded territory in Brazil, not a national checklist: a bird list from eBird or Avibase is more complete. The counts follow recording effort as much as wildlife, so a country with more visitors and more naturalists will show more of both.
The species with the most open occurrence records in Brazil, among those a photograph exists for. Most recorded is not most numerous: it rewards animals that are common, conspicuous and live where people go.

Thraupis sayaca

Pitangus sulphuratus

Turdus rufiventris

Patagioenas picazuro

Turdus leucomelas

Furnarius rufus

Coereba flaveola

Columbina talpacoti

Pygochelidon cyanoleuca

Psittacara leucophthalmus

Eupetomena macroura

Brotogeris tirica
The reference database has no regions filed under Brazil.
The field guide covers Brazil on the map, but none of its species have an entry written for them yet.