GREEN-WINGED MACAWS
by William Horsfield

Introduction
The Green-winged Macaw, Ara choloptera is one of my all-time favourite large macaws. In spite of their enormous size relative to other parrots, (only the Hyacinth, Buffon's and Central American Scarlet may exceed their length and wingspan measurements) the Green-winged is essentially a very gentle and sensitive bird. This disposition is clearly observed with many handraised individuals whose exceptional tameness and overall gentleness with trusted owners and their families belies their strength and can only be marveled at. Having said that, the massive beak of this bird can inflict serious injury and is not to be trifled with uninvited!

The Green-winged is often confused with the Scarlet Macaw but is a larger bird and has a green band on the wing and no yellow as seen in that of the Scarlet. The Green-winged also has tracks of red facial feathers and the bare white skin on the face does not flush red when the bird is stressed or excited as in some of the other macaws like Scarlet and Blue & Gold.

Management
Being an extremely large, powerful bird the Green-winged needs to be housed in a well-constructed and spacious aviary. They are inclined to destroy wire that is substandard and anything less than 2.5mm diameter is likely to be damaged. We use 25x25mm aperture on the Greenwings aviaries, as this doesn't allow the bird to open its beak wide enough to use its maximum force. As with any bird that chews on galvanized wire, this poses a severe health risk due to the accidental ingestion of small metal particles while the chewing takes place. Increased levels of zinc or lead in the body are often the cause of so-called "unknown death" in parrots and any chewing of wire or cage clips is highly dangerous. Providing toys to pets consisting of bunches of old keys and galvanized objects like bells is also potentially lethal. Leaded paints including cage and household paints, the backs of certain mirrors, contaminated food and bone meal products, gas exhaust fumes and lead contaminated water from old water pipes are also all hidden sources of potential lead contamination. Pets can be safely entertained and amused with many safe objects and parrot toys. A length of parrot 'Worry Beads' made by Sharon Bloch in the USA and featured in issue 46 of Parrots Magazine published in the UK looks very interesting and useful in keeping a bird busy. They apparently work very well to distract individuals that feather-pluck.

The length and wingspan of a Green-winged measures approx. 83cm & 117cm respectively. Aviaries should therefore be a minimum of 1,8m wide x 2m high x 5m long. Coarse, washed river sand is suitable as a deep covering for the flight section while a cement floor in the sheltered portion of the aviary makes cleaning much easier. Greenwings can also be housed in suspended flights but these need to be as large as the conventional cages.

Stainless steel feeding and water dishes are recommended as they are hygienic and non-destructible. Micro water-sprayer systems are an essential component of the aviary design and Greenwings love to bathe. They often hang upside down and flap their wings with delight during these showers. I use the new product VIRUKILL as disinfectant agent of choice at this time and it is used in our footbaths, hand-sprayers and in the pressurized unit that is used to disinfect the aviary buildings.

Greenwings are not necessarily noisy macaws but certainly have harsh, loud calls and some pairs may incite the wrath of neighbours and are therefore not recommended in a breeding environment for built-up urban areas. They are long-lived and can be expected to breed well into their 30's and even into their 40's given correct nutrition and ideal management.

With their large naked facial patches, they are very susceptible to bee stings and attacks by bees from swarm invasions into nests can be prevented by regular use of bee repellant spray onto the nests (BYE BYE BEE is advertised in Avizandum)

Breeding
Captive-bred Greenwings can be expected to breed at 5 years of age. Wild-caught individuals may take longer than twice this period to acclimatize in captivity and are not recommended although still available in this country. There are enough breeders of Greenwings to be able to obtain healthy, locally-bred birds without supporting the continued trade in wild caught specimens. Only in certain cases when rare species are being established in captive breeding programmes or when inbreeding becomes a health risk should wild-caught birds become an option and this certainly does not pertain to the Green-winged. Macaws in the wild eat a diet high in carbohydrates and fat and low in protein. The attempt should be to duplicate this in captivity. A diet consisting of fruit and vegetables, nuts and seeds and a commercial softfood like Avi-Plus is ideal. The species is not strictly seasonal and may breed at any time of the year although individual pairs often repeat a similar cycle every year. It is crucial therefore to feed a balanced diet year round. They are a sensitive species and one of the harder of the large macaws to breed. Compatibility is paramount to success and pairs must be very well bonded. Positive signs to look out for are regular beak gripping and much mutual preening. The pair are seldom apart and like to remain close to one another. When one flies then the other also flies. Raising their wings simultaneously is a sign of territoriality display and another positive sign. I prefer to offer the Greenwings large natural logs as nests and I position these horizontally above human head height. We provide wooden chips as a nesting substrate which can be mixed with well sifted river sand. All macaws mate sitting side by side (mostly on the perch) facing the same direction. Greenwings lay 3-4 eggs and only the hen incubates although the male may occupy the nest with her at times. Generally he stands guard close by outside the nest. Greenwings require 14 mm leg bands and stainless steel rings are by far the best option. Excellent bands are obtainable from E&L Enterprises who advertise in Avizandum. Artificial incubation temperature is 37.5°C with Relative Humidity approx 50%. When the chick internally pips into the airspace (or at latest when 1st external chip appears) turning must be stopped and the egg placed with chip facing upwards in the hatcher. The temperature stays the same but at this point the %RH can be increased to 65-70%. Newly hatched chicks need to be fed every two hours and are straightforward to raise if the breeder has sufficient experience. We use Kaytee Macaw formula for incubator hatched chicks and Avi-Plus Premium for partially parent raised chicks. Great care must be taken not to feed formula that is too hot (chicks will readily accept this) as serious crop burns are commonly seen by the specialist avian vets in SA. Microwaves are notorious for causing this type of unnecessary accident. Green-winged may take anything up to 5 months and should not be pressured into eating on their own until they are they are ready as independence is reached through a gradual learning process.

Disease
Many of the wild-caught Greenwings imported into South Africa have traditionally suffered from Pappilomatous disease. The species in general is the most commonly afflicted of all macaws. Birds with Papillomatosis often exhibit no clinical signs and the disease is not easily observed unless a specific examination is undertaken. In affected Greenwings small pinky-white fleshy or granular-appearing growths that bleed easily are usually observed in the oral cavity and at the skin to mucous membrane junction in the cloaca. Affected birds often fail to breed and hens often prolapse the cloaca if they lay an egg While the disease has no known causative agent as yet, it is viewed as infectious and it is recommended that prospective buyers have a full examination performed by a specialist avian veterinarian. Psittacine Beak and Feather DiseaseVirus (PBFDV) is rife in South African collections and cases of equally devastating Avian Polyoma Virus have been confirmed in our country. Diagnostic tests from a drop of blood are available for both these as well as for the rarer but equally dangerous Pacheco's virus as well as for the commonly encountered Chlamydiosis. MDS in Durban offers this service. Psittacine Proventricular Dilatation Syndrome (formerly Macaw Wasting disease) has also been diagnosed in South Africa but is difficult to diagnose except on autopsy. Interesting cases of self-mutilation of toes and feet in birds subsequently diagnosed with PPDS on autopsy have been observed recently (pers. obser. C. Kingsley)

Field of vision
Macaws are extremely visually sensitive birds. The position of the eye is lateral in the skull. Laterally positioned eyes provide a larger field of vision than those with frontally located eyes. For the most part, macaws have monocular vision, since only one eye is focused on any one object at any particular moment. They commonly will turn their head so that one eye faces toward the desired object in order to focus their eye on a precise location. The eyes are highly mobile and each eye can be moved independently, allowing for greater scanning ability. Their binocular field of vision is significantly less with both eyes being focused on the same object and movement of the two eyes becomes coordinated. Diurnal birds (those active during the day) like Greenwings tend to have a flat eyeball. The flat shape is maintained and supported by a ring of twelve bones, the sclerotic ossicles. The cornea and lens are optically clear and appear to transmit wavelengths down to about 350nm, thus rendering near ultraviolet radiation visible and absorbing only those UV wavelengths which are not physiologically destructive. This means that they are able to not only appreciate colours not visible to man but that their colour vision is also more acute than man's. When excited and during courtship displays, adolescent and adult birds will alternatively constrict and dilate their pupils.

Conclusion
Of the many pairs of Green-winged Macaws held in avicultural collections in South Africa, only a small percentage are productive in terms of good breeding results. More effort needs to be made to encourage the non-producing pairs to breed and perhaps this article will provide some of the insight and information necessary to that end.

References
The Large Macaws, Their Care, Breeding and Conservation. J.Abramson, B.L.Speer, J.B.Thompsen