Occurrence of European cuckoo was tested as surrogate for biodiversity.
Taxonomic diversity (TD) and functional diversity (FRic, FEve, FDiv) were estimated.
Average evolutionary distinctiveness (ED) was estimated in each bird community.
Cuckoo occurrence predicts TD, FRic, and FEve but not ED of bird communities.
The cuckoo offers a cost-effective conservation tool, useful for citizen science.