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Taxonomy and systematics[edit]
Two subspecies are universally accepted:[1] * Congo African Grey Parrot (Psittacus erithacus erithacus):
This is the nominate subspecies, larger than the Timneh at about 33 cm (13 in) long, with light-grey feathers, cherry-red tails, and an all-black beak.[1] Immature birds of this subspecies have tails with a darker, duller red towards the tip (Juniper and Parr 1999) until their first moult, which occurs by 18 months of age. These birds also initially have grey irises, which change to a pale yellow colour by the time the bird is a year old. The Congo Grey Parrot is found on the islands of Príncipe and Bioko, and is distributed from southeastern Ivory Coast to western Kenya, northwest Tanzania, southern Democratic Republic of the Congo (DRC), and northern Angola. In aviculture, it is often called a "CAG". * Timneh African Grey Parrot (Psittacus erithacus timneh, or Psittacus timneh):
The Timneh African Grey Parrot is slightly smaller in size than the Congo, but intelligence and talking ability remain comparable. They can range from about 22–28 cm in total length, and are considered a medium size parrot. The Timneh has a darker charcoal grey colouring, a darker maroon tail, and a light, horn-coloured area to part of the upper mandible. Timneh parrots are endemic to the western parts of the moist Upper Guinea forests and bordering savannas of West Africa from Guinea-Bissau, Sierra Leone, and southern Mali east to at least 70 km (43 mi) east of the Bandama River in Ivory Coast. It is often called a "TAG". As pets, Timnehs usually begin learning to speak earlier than Congos as they mature slightly earlier. The Timneh parrot also has a reputation of being less nervous around strangers and novel situations than the Congo, but whether this is true or not is still debated. In 2012, Birdlife International gave the Timneh Parrot full species status[2] and it was classified as Vulnerable.[3]
Some aviculturalists recognize third and fourth subspecies, but these are not distinguishable in scientific studies.[4]
Illness and Disease[edit]
The African Grey Parrot (Psittacus erithacus erithacus) has been known at times to contract a non-infectious inflammatory lung disease called Lipid Pneumonia. Lipid Pneumonia can be classified as exogenous or endogenous depending on whether or not the animal inhaled outside material. A necropsy shows that the lungs of a Grey Parrot with Endogenous Lipid Pneumonia (EnLP) are firm with a diffuse grey discoloration. EnLP is a common illness in other animals as well.[5] The Congo African Grey Parrot is also one of the three parrots that scientists found to commonly suffer from dehydration. They use Plasma Osmolality to find more information about the form of dehydration the African Grey Parrot has. Often, there is need to find replacement fluids for the Parrots.[6] I added the comment that another disease that a lot of the African Grey Parrots get is cardiomyopathy which is a heart disease that usually presents at a young age. It is believed for the heart disease is genetically inherited from parents of the same breed. Some other common symptoms and illnesses in these birds are weakness, coelomic cavity, and retardation. [7] The African Grey Parrot has been known to contract Beak and feather disease virus (BFDV) which causes a highly contagious and sometimes fatal, psittacine beak and feather disease in parrots.[8]
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Behavior and ecology[edit]
Longevity[edit]
Like many large parrots, the African Grey is a long-lived bird. The Animal Ageing and Longevity Database states the longest reliably recorded longevity for the species in captivity as 49.7 years. Also acknowledged are claims of captive African Grey parrots reaching the ages of 73 and 93,[9] whereas the World Parrot Trust lists a longevity of 50–60 years for an African Grey in captivity.[10] The Guinness Book of World Records listed a grey parrot that allegedly lived in captivity for 72 years as the longest-lived specimen for the species.[11]
Intelligence[edit]
Further information: Talking bird
Unlike other parrots, wild African Greys have been documented imitating the calls of several other species.
Irene Pepperberg's research with captive African Greys, most notably with a bird named Alex, has scientifically demonstrated that African Greys possess the ability to associate simple human words with meanings, and to intelligently apply the abstract concepts of shape, colour, number, zero-sense, etc. According to Pepperberg and other ornithologists, they perform many cognitive tasks at the level of dolphins, chimpanzees, and even human toddlers. [12] Pepperberg also gave Alex some tutors so he could be able to learn English. Which suggests that African Grey Parrots do not just inherit the speaking ability. Besides Alex being able to label objects he has the ability to know what his wants are. Which suggest the African Grey Parrot can understand the difference to features and feelings. [13] In general, it has been shown that African Grey Parrots are able to learn relatively quickly, though they are limited to simple and non-abstract mediums of thinking.[14] They have been shown to be able to make cognitive inferences, but, like apes, have inter-individual differences in intelligence. For example, in one experiment involving food hidden under cups, it was shown that African Greys can identify where the food is, usually if shown its original location at first.[15]
Many pet Congo African Greys learn to speak in their second or third year.[citation needed] Timnehs are generally observed to start speaking earlier, some in their late first year.[16]Both subspecies seem to have the same ability and tendency to produce human speech, but vocal ability and proclivity may range widely among individual birds. The African Grey Parrots tend to use more specific calls which can be known as "Stimulus Specificity", since there is a stimulus involved with the vocaliztion that the parrots have.[17] One notable African Grey is N'kisi, which in 2004 was said to have a vocabulary of over 950 words and, like Pepperberg's Alex, was noted for creative use of language.[18] For example, when Jane Goodall visited N'kisi in his New York home, he greeted her with "Got a chimp?" because he had seen pictures of her with chimpanzees in Africa.[19]
A study published in 2011, led by Dalila Bovet of Paris West University Nanterre La Défense, demonstrated African Grey parrots were able to coordinate and collaborate with each other to an extent. They were able to solve problems set by scientists—for example, two birds could pull strings at the same time to obtain food. In another example, one bird stood on a perch to release a food-laden tray, while the other pulled the tray out from the test apparatus. Both would then feed. The birds in question were observed waiting for their partners to perform the necessary actions so their behaviour could be synchronized. The parrots appeared to express individual preferences as to which of the other test birds they would work with.[20]
Noises[edit]
Wild African Grey Parrots often whistle, click, or make other sounds. An African Grey's owner should expect to hear regular renditions of microwaves, telephones, alarm clocks, video games, and other electronic sounds, as well as dripping water, wild birds, and any other sound often heard by the parrot. African Greys have even been known to repeat the profanity they heard from an owner even after they no longer live with that owner. African Greys also have the ability to mimic, and distinguish between, the different voices they hear. The African Grey parrots could possibly give different alarm calls for different predators coming their way.[17]