Subspecies
There are two subspecies:
Congo African Grey parrot, Psittacus erithacus erithacus - these are
larger birds (about 12 inches/30cm long) with light grey feathers, cherry
red tails and black beaks. A
Congo is often called a "CAG".
Timneh African Grey parrot
Psittacus erithacus timneh - these are smaller
in size, have a darker charcoal gray coloring, a darker maroon tail, and a
light, horn colored upper mandible. A Timneh is often called a "TAG".
Some avian enthusiasts (incorrectly) recognize a third subspecies, Ghana
African Grey (Psittacus erithacus princeps). This bird is described to be
similar to the Congo African greys, but darker and slightly smaller;
however, scientifically this subspecies has not been found to be
recognizable. Among breeders, there is said to be a fourth subspecies, the
Cameroon African Grey, most often referred to as the big silvers.