
These are species with at least one recorded territory in Argentina, 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 Argentina, among those a photograph exists for. Most recorded is not most numerous: it rewards animals that are common, conspicuous and live where people go.

Furnarius rufus

Zenaida auriculata

Myiopsitta monachus

Milvago chimango

Pitangus sulphuratus

Patagioenas picazuro

Turdus rufiventris

Vanellus chilensis

Mimus saturninus

Zonotrichia capensis

Agelaioides badius

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