Redescription of African Goshawks, Accipiter tachiro, from Bioko and the adjacent mainland

Examination of museum specimens of Accipiter tachiro established that the race lopezi, endemic to the island of Bioko, is similar in size to conspecifics on the adjacent Cameroon mainland. Compared to continental forms, adult lopezi have rather more richly-coloured underparts with more saturated flanks, thighs and breast and, in some, even some rufous on the throat, a feature unique to this population. The three white tail spots are smaller, but still well marked, and rounded. Juveniles have spotted underparts, similar to the closest relatives on the mainland, and the thighs are decidedly washed rufous, heralding the bright colour of the adult. On morphological ond geographical grounds the race macroscelides is considered to be lopezi's ancestor. Because of the occurrence of intermediate specimens in the area east of Mount Cameroon, the races macroscelides and toussenelii are best considered to belong to a single biological species.