Typically known as African Grey Parrots or just Grey Parrots. The two recognized subspecies are usually referred to as Congo African Greys (CAGs) or Timneh African Greys (TAGs). The species' scientific (Latin) name is Psittacus erithacus. Psittacus is the genus to which Grey Parrots belong, while erithacus refers to the specific species wihin the genus.

Biological classification systems are based on the following hierarchical system: Phylum, Class/Subclass, (Super)Order, Family, Genus, Species, and Subspecies--other sub-catagories can also be inserted at various places. There is a great deal of debate about where the different subcatagories fit, and even where birds should fit in the grand scheme of biological classification. For African Grey Parrots the generally accepted hierarchical system gives the following classification:

• Phylum: Cordata
• Sub-phylum: Vertebrata
• Class: Sauropsida (some sources use Aves, Reptilia, or Dinosauria)
• Subclass: Diapsida
• Infraclass: Neodiaspida
• Parvclass: Archosauromorpha
• Cohort: Archosauria
• Superorder: Aves
• Order: Neornithes (modern birds)
• Suborder: Neognathae
• Infraorder: Psittaciformes
• Family: Psittacidae (Parrots)
• Genus: Psittacus
• Species: Psittacus erithacus
• Subspecies: P. e. erithacus (Congo African Grey) and P. e. timneh (Timneh African Grey)

• Length: African Grey Parrots are approximately 33 centimeters long; CAGs are larger than TAGs--30 to 35 centimeters versus 23 to 28 centimeters.
• Wings: 232 to 259 millimeters in length.
• Tails: 79 to 95 mm long.
• Bills: 32 to 39 mm long.
• Tarsus: 25 to 28 mm long.
• Weight: Most captive greys weigh 500 to 550 grams.

Parrots are long-lived animals. Although the average life-span of an African Grey Parrot in captivity is about 15 years, with proper care, feeding, and stimulation, they are more than capable of reaching 50 years or more.

African Grey Parrots are well known for being one of the most vocal of bird species. In the wild they have a wide repertoire of calls, including squawks, whistles, shrieks, and screams. They are also known to mimic other bird species and other noises in the wild. Wild calls include harsh grating scraark scraark scraark, scree-at, scrat scrat, and creee-ar creee-ar calls, as well as calls that sound like honking geese. They will also whistle a variety of sounds, from eerie whistles to bubbling sounds. Alarm calls are generally loud screech signals.

In captivity, young birds often babble (Dr. Irene Pepperberg refers to this as "graylish") while practicing mimicing human sounds. It can take some time before greys are able to produce the strange sounds that we take for granted in human language. Greys are often 12 to 18 months old before they utter their first clearly understandable words, although some may begin talking as early as 6 months. It is likely that parrots who are stimulated and talked to often, will start talking earlier than those who are left alone more. As with most animals, daily interaction is the key to social development. With careful teaching, greys can learn the meaning of words and phrases, including correct context, categories of objects, and numbers. They are capable of developing a working vocabulary of dozens of words that are used correctly.

African Grey Parrots are considered sedentary--that means they are not a migratory species. They are still considered common in undisturbed primary and secondary rain forest. Congo African Greys are believed to be particularly abundant in the Congo basin. However, loss of habitat in many areas, especially in West Africa (Nigeria to Sierra Leone) have resulted in local declines in populations, as has trapping for the pet trade. The Timneh African Grey should be considered particularly vulnerable due to serious habitat losses occurring throughout its West African range. During the 1980s, the African Grey was the second most heavily traded parrot species in the world. Such impacts have made the bird rare in certain areas, such as Liberia, Ghana, Kenya, and around many cities within their range--for the simple reason that parrot populations near human population centers have been hardest hit by collectors. In areas where the species is still common, flocks of up to 10,000 individuals may be seen at communal roosts.

African Grey Parrots live in primary and secondary rain forest habitats, favoring forest edge habitats, clearings, gallery forest, and mangroves. In some areas they can also be found in altered habitats such as cultivated land and gardens. They tend to be a lowland species, although they have been seen at elevations up to 2,200 meters. African Greys are found at their highest densities in lowland primary forest, at intermediate densities in montane primary forest, and at their lowest densities in coconut plantations. Ten thousand birds may congregate at communal roosts. Preferred roosting sites are often trees or palms located over water or on islands in the middle of rivers.

African Grey Parrots feed on a variety of seeds, nuts, fruits, and berries. Birds disperse after roosting in large groups, and forage in smaller groups of up to 30 individuals. They typically feed in the top branches of trees. Fruits and seeds of a number of species are taken, including Ficus, Heisteria, Dacryodes, Petersianthus, Combretum, Macaranga, Raphia, Harungana, Ceiba, Blighia, Bombax, Celtis, Caccia, Parkia, Terminalia, and Prunus. They particularly like the flesh of the oil-palm Elaeis guineensis. In agricultural areas, flocks of Greys have been known to damage maize crops.

Sexual Dimorphism: There is no sexual dimorphism in African Grey Parrots. Both sexes are visually identical. Sexing in captive birds is done through DNA analysis, using blood or pulled feathers. Immature birds can be distinguished from adults by their tails which are darker red towards the tip, the rey tinge on their undertail-coverts, and by their grey iris; adult greys have a bright yellow iris.

Reproduction: African Grey Parrots are cavity dwellers. They do not build a nest, but lay their eggs in cavities found in trees (Terminalia, Ceiba, or Distemonathus). The cavity is usually located 10 to 30 meters above the ground. These parrots sometimes nest in loose colonies of up to several hundred pairs, but are usually solitary. In East African, breeding takes place during the dry season, particularly in January-February and June-July. Two or three eggs are laid, although there may be as many as four.

Two (possibly three) races or subspecies of African Grey Parrots are recognized (a few authors classify them as separate species, but most keep the subspecific classification):

• Congo African Grey, Psittacus erithacus erithacus This is the nominate race and is the "typical" African Grey Parrot. Found in Equatorial Africa from south-eastern Côte d'Ivoire to western Kenya, northwestern Tanzania, southern Congo/Zaire, and northern Angola.
• Timneh African Grey, Psittacus erithacus timneh. Found in western Upper Guinea forests, Guinea-Bissau, Sierra Leone, Southern Mali, and Côte d'Ivoire. This subspecies is considered darker than the nominate (CAG) race, and rather than having red tail feathers, its tail coloration is duller and darker, tending more toward maroon than red. Their upper tail coverts are grey tinged red (not scarlet as in CAGs). Their upper mandible is red tipped in black. Overall, TAGs are smaller than CAG (23 to 28 cm versus 30 to 35 centimeters).

  A third possible subspecies is:

• Psittacus erithacus princeps found only on the Príncipe and Bioko Islands in the Gulf of Guinea, which is said to be larger and darker than the nominate (CAG) subspecies. However, most authorities doubt the validity of this third subspecies.