Size cline not subspeciation in the Hooded Vulture

Wing, tail and bill lengths of Hooded Vultures were measured on 36 wild-caught birds and 75 in museum collections. A further 60 measurements were taken from literature, and 40 measurements were received from the Musée royal de l’Afrique centrale (Tervuren, Belgium). By grouping them into regions of Africa it was shown that the smallest birds were in West Africa and the largest in southern Africa (which is well known), with a gradation in between. Sizes varied according to a cline, and were correlated with average altitude. Given that the species has the same colouration (head, caruncles, plumage) from one end of the range to the other, indeed that populations are contiguous from Senegal to South Africa, then this goes against recognising any subspecies, but rather an intraspecific trend in size