no locality = Senegal.
Hitherto treated as conspecific with P. nigricollis, but differs in its pale vs dark eye (3); olive vs black hindneck (3); olive-green vs olive-tinged blackish-grey upperparts in male (2); yellowish-olive vs dark olive or black crown in female (ns); bill marginally longer (effect size 1.42; score 1); presumed narrow hybrid zone in S Cameroon (2). Birds from Bioko described as additional race (po) on basis of longer and heavier bill; possibly worthy of recognition, but further study required. Treated as monotypic.
Gambia and S Senegal E to Nigeria; also Bioko.