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

Sula variegata

Zenaida meloda

Psarocolius angustifrons

Ramphocelus carbo

Zonotrichia capensis

Turdus chiguanco

Mimus longicaudatus

Thraupis episcopus

Cacicus cela

Columbina cruziana

Dives warczewiczi

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