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

Pycnonotus barbatus

Uraeginthus angolensis

Cossypha heuglini

Turtur chalcospilos

Laniarius major

Streptopelia capicola

Merops bullockoides

Motacilla aguimp

Dryoscopus cubla

Dicrurus adsimilis

Actophilornis africanus

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