Timneh African Grey
The Timneh African grey is slightly smaller than the Congo Grey, and the Timneh's tail feathers are darker (maroon). Overall the Timneh usually has has slightly darker coloration than the Congo, especially over the back (although not always the case). While the Congo's beak is grey, the Timneh's upper mandible is bone colored with a dark edge, while the lower mandible is grey.
African greys are extremely intelligent birds. The most famous African Grey is Alex, a bird studied for years by Dr. Irene Pepper Berg. Alex has been shown to have the ability to process information and make appropriate choices with the correct choice of words, and understand concepts such as color or shape (i.e. he is not simply displaying previously trained behaviors).
Greys are excellent mimics, and many (though not all) are excellent talkers, with a capacity of over 2000 words. Even those that don't repeat words are very adept at repeating household noises such as the telephone or doorbell, often well enough to confuse their owners! Most greys have a large collection of sounds they repeat. As the studies with Alex have shown, greys have a unique capacity for putting their words and sounds into the right context as opposed to simply repeating them, showing their intelligence.
They have a reputation as one-person birds, but that is largely because often only one person in a household spends enough time with a grey to really form a close bond. Make an effort to socialize a grey with lots of people.
Lifespan~ 50+ years