Based on DNA evidence, Psittaciformes (cockatoos and parrots), falcons and passerines (perching birds) were the last groups to split off from the modern birds trunk, the Neoaves, an event which most likely happened in Gondwana around 65 mya. The Psittaciformes fall between the Falconidae and the suboscine passerines, which include pittas and manikins but, on the bird family tree, they are not far from the oscine passerines which include other great vocal mimics like the lyrebirds, mynahs and crows as well as the beautiful singing finches.
The current first undisputed Psittaciforme fossil is that of a cockatoo from Queensland from the middle Miocene, 20 mya but DNA analysis suggests that New Zealand Parrots, the Strigopidae, including the Kakapo, Kea and Kaka are an ancient group that split off before the emergence of the common ancestor of the cockatoos and the remaining parrots of the world.
Cockatiels were one of the earliest offshoots of the Cacatuidae family, followed by four other monotypic genera: the Major Mitchell’s Cockatoo, Galah, Gang Gang and Palm Cockatoo. The largest branches, the Calyptorhynchus which contains 5 black coloured cockatoos and the Cactua which contains 11 species of white-plumed cockatoos were the most recently evolved. Cockatoos are only found in the wild in Australia, New Guinea and islands off South East Asia but they have become popular pets, especially cockatiels which are easy to keep and hardy.
Cockatoos make excellent pets but they can be noisy, need space and owners need to be prepared to spend time to look after them well. Sulphur Crested Cockatoos, Long-billed Corellas, Little Corellas and Galahs are all commonly kept. Major Mitchell (Pink) Cockatoos and Gang Gang Cockatoos require licences to keep, as do all of the black cockatoos, some of which are threatened or endangered. These are better kept by experienced bird keepers and aviculturists. Indonesian species, including Umbrella and Salmon Crested Cockatoos are held in low numbers, mostly by breeders.
Diet, Foraging & Digestive System
While there is some species variation, in the wild cockatoos typically eat seed, tubers, corms, fruit, flowers and insects and forage on the ground to get grit and minerals. Their digestive systems are those typical of granivorous birds and include a strong curved beak, a crop, proventriculus and ventriculus. Suitable diets for pet cockatoos include offering on a daily basis: a large parrot seed mix, a selection of high vitamin A containing green and yellow vegetables & fruits (e.g. spinach, beans, peas and broccoli) and commercial pellets appropriate for the species. Cuttlefish bone or a mineral block should be available. Grit is optional. All seed diets (which are high in kilojoules but low in Vitamins A and D and a range of other nutrients) are inappropriate and should be avoided! Problems are most likely to manifest as juveniles showing bone deformities from calcium and vitamin D deficiencies or adults showing obesity, fatty tumors (lipomas) and bumble foot (pododermatitis).
As with parrots, cockatoos are intelligent and can show vocal communication skills that are only seen in higher primates and cetaceans (e.g. dolphins). Individuals are able to learn words and phrases from human languages, most often just mimicking but in some cases using words in appropriate context, e.g. One Sulphur Crested Cockatoo amused everyone in our waiting room saying “Wanna go home” quite clearly and a galah once came out of her carry box saying “Hello Doctor Pat”. Owners often give other examples.
Cockatoos have curved bills and showy crests which curve forward in most Australian species but backwards in some of the Indonesian species, such as the Umbrella and Salmon Crested Cockatoo, which have been widely kept as pets overseas and are now being seen more frequently in Australia. Natural branches from native Australian trees or other toys suitable for destruction should be provided for beak care and enrichment.
Cockatoos are monogamous and nest in tree hollows but will form flocks and fly long distances for foraging and protection from predators. Individuals act as guards and vocalize loudly to warn of the approach of possible danger. Cockatoos are also inclined to vocalize loudly if they need to be restrained and noise can be a problem in cockatoos kept in suburban aviaries. It is not technically possible safely alter voice in these loud birds by any surgical means, we recommend the use of force-free training techniques to reduce unwanted vocalizations or, if this does not address the problem, re-homing where the noise will not be an issue.
As pets, individuals will often form strong, sexually based bonds with one carer while being aggressive towards other people. Aggression over mates and nest sites can occur, especially in early spring and especially with Major Mitchell cockatoos where males may come into a breeding condition earlier than females and can kill their partner who may not yet be ready to breed.
Skin and Feathers
Feather colours in cockatoos are muted because these species are not able to produce the bright red and green pigments seen in other psittacine birds and because their feathers are normally covered with white powder down produced from specialized feathers located on the hips that can be seen as a fine talcum powder-like substance on the hands after handling. Powder down may induce allergies that manifest as respiratory disease in some humans or in South American birds kept in contact with cockatoos.
Feather colour change from grey to black and increased intensity of pink pigments in galahs can be seen in liver disease such as with chlamydiosis, mycotoxicosis and, less commonly, circovirus.
Feather destructive behaviour is common in these intelligent, sensitive birds and may have both organic disease and behavioural causes. Veterinary advice should be sought early if the problem occurs as behavioural problems left untreated become more difficult to resolve. A thorough history and diagnostic workup for systemic disease are useful starting points to work through these often complex cases.
Feet and Legs
In common with all psittacine birds, cockatoos are zygodactyl, the 1st and 4th digits on the feet are orientated caudally while the 2nd and 3rd point cranially. Cockatoos can have either right or left foot preference with left foot preference generally predominating. While normal cockatoos stand on their interdigital pads (‘the ball of their foot’), obese birds or those with arthritis can rest on their intertarsal joints (the ‘heels’) causing ulceration, infection and further exacerbating any arthritis. Wound treatment, bandaging, antibiotics, anti-inflammatory treatment along with improved diet, perches, weight loss and exercise will help in most cases.
Papillomatous (wart-like) growths are occasionally seen on the feet of some cockatoos, some of which are caused by herpes virus infections. Some will resolve with topical treatment or surgical removal but recurrence can occur.
Egg yolk related peritonitis, internal laying and abdominal muscle thinning and/or hernias in pet cockatoos can be associated with excess hormone production caused by long term high nutrient diets and pair bonding with humans who are not able to fulfill the need for the bird to nest and rear a normal clutch of chicks. These problems can also be associated with ovarian or oviductal cancers. Avoiding petting or contact that might induce female hormone release along with an anti-reproductive hormone implant (deslorelin) can be helpful in many of cases. In some cases surgery to remove the oviduct, often in addition to deslorelin implant and environmental change is needed.
Top 10 Health Problems of Cockatoos (see separate pages for more information)