In the 1920s James Chapin noted the similarities between the nicators and both the bulbuls (Pycnonotidae) and the bushshrikes (Malaconotidae).

Storrs Olson argued that the genus was more closely related to the bushshrikes, as the nicators lacked the ossification of the nostril found in all other bulbuls.

[3] A number of features, including the position of the facial bristles (which are preorbital rather than rictal), their nests and the calls, make the genus unique, and DNA studies have recently suggested that the genus is best treated as a monogeneric family.

[6] Within the genus, the western and eastern nicators are considered to form a superspecies and are sometimes treated as the same species.

The western nicator has a mostly continuous distribution from Senegal to eastern Uganda and northern Angola.