There are two species of African Greys:
The Congo, P. e. erithacus, is the larger of the two birds, with bright red tail feathers and a black beak. A Congo is generally characterized as slightly more intelligent, but also more high-strung than Timnehs.
The Timneh, P. e. timneh, is smaller, its tail feathers are more of a maroon-grey mixture, and its beak includes tints of a reddish-beige colour. These birds are characteristically less high-strung and mellower than a Congo