BWP's format and breadth influenced the development of regional avifaunas for other parts of the world, notably The Birds of Africa.

The boundary used for the region included Iceland, but not Greenland; all of Macaronesia (islands off Portugal and North Africa); North Africa; the northern parts of the Arabian Peninsula; Iraq and Kuwait, but not Iran; and Russia west of the Urals.

A number of subsequent papers have questioned the appropriateness of this boundary, particularly its southern and southeastern delimitations, among them Martins & Hirschfeld (1994).

[2] Martins and Hirschfeld published a more detailed paper in 1998, discussing the boundary in Iran and the Arabian Peninsula.

[3] Ullman (2000) disagreed with their conclusions regarding the Arabian enclaves, however, arguing that their depauperate avifauna, when compared to species-rich areas in northeast Africa, justified inclusion of the whole of Arabia in the Western Palearctic.