The agouti (Dasyprocta) – and perhaps other rodents – eat the outer layer of palm nuts, but cannot crack the kernel. The macaws go down to the ground and eat the kernels of the nuts that have been opened by agoutis. It has been suggested that the macaws’ action in dropping the nuts to the ground is deliberate, thus saving them time and effort in opening the nuts! However, all parrots are wasteful feeders – as most owners know – and drop many food items. It is said that the only creature that can open the outer covering, or capsule, of a mature Brazil nut (Bertholletia excelsa) is not a macaw, but the agouti which can gnaw it open, but a macaw’s gape is not wide enough to hold it. The capsule can weigh as much as 2 kilos and contain 25 nuts. Macaws could only eat these nuts in the unripe stage unless they descended to the ground. Scarlet Macaws eat the fruits in the green stage, and Golden (Queen of Bavaria’s) Conures have also been seen feeding in these trees. Green-winged Macaws, with their larger beaks than Scarlets, can open larger, harder nuts, including the young Brazil fruits.

The palm nuts preferred by Hyacinthine and Blue-throated Macaws are those of Acrocomia and Attalea palms. Analysis of the Acrocomia nut has shown that it has a fat content of 67% and a protein content of 13%. A high fat content in the diet of the larger macaws, from sunflower seed or nuts, is essential if these birds are to breed in our aviaries. Macadamia, pecan and Brazil nuts have the highest fat content: approximately 76%, 72% and 66% respectively.

Some years ago I visited a breeder in Australia, who had imported macaws from Europe, which ceased to breed a few months after he acquired them. He had withheld sunflower seed in the belief that it caused feather plucking, and he did not feed nuts. At this time, macaws cost $10,000 each, so he was quite pleased to be hatching lots of young a few months after I suggested he should give his macaws unlimited quantities of sunflower seed. I had been shocked to see that he had fed unsuitable seeds such as millet! The large macaws need nuts, such as walnut, Brazil and macadamia.

Nuts have been described as the perfect food for humans, and the fact that some species of macaws and parrots eat little else tells us that they are also a perfectly balanced food for these birds. Nuts have a very high energy content. Depending on the season, many wild parrots must fly long distances daily to find their food, thus they use up a lot of energy.

Our birds use far less energy, so their daily allowance of nuts should be rationed, except when used as a stimulus to breeding. Look under the top line marked kcal, for kilocalories, in each of these tables, and you will see the number of calories in each 100 grams of nuts. According to Ritchie, Harrison and Harrison’s book, Avian Medicine Principles and Application, a captive Amazon parrot needs 100kcals of energy daily, so you can see why it would be unwise to offer more than half a walnut daily. This half walnut for a Sun Conure weighing only 120g, or one third the weight of an Amazon, is his ration for one week! In actual fact, I would not offer walnuts to Amazons and conures, because these birds easily become obese. Nuts are very high in fat, but also contain valuable elements, such as calcium and Vitamin E. The nuts we buy for our birds can keep for one year if correctly stored in a refrigerator.

It is difficult to find nutritional analyses for nuts on which parrots feed, unless they are also used for human consumption. It is known that the fruits of the licuri palm (Syagrus coronata) are high in Vitamin A or, more correctly, beta-carotene. They are eaten by the people of the arid Brazilian region where this macaw occurs; these nuts have the potential to be used as a human vitamin supplement. They also have a high calorie content. The moriche palm (Mauritia species) is also high in Vitamin A. Its fruits and nuts are eaten by many parrot species, including the Blue-headed Macaw. A large part of the diet of the Red-bellied Macaws seen here consists of these palm fruits. Incidentally, of all the macaws, this species fares least well in captivity and its problems appear to be related to diet and exercise.

A deficiency of Vitamin A has severe consequences and is most likely to occur in those parrots fed mainly on seed. One of the best sources of Vitamin A is the African oil palm which is grown throughout the tropics and, sadly, its planting is the cause of destruction of vast areas of rainforest. The extract from its fruit has one of the highest known concentrations of Vitamin A – but other oily palm fruits are probably equally beneficial. Many macaws and large parrots, such as African Greys, eagerly consume the nuts of the oil palm. A palm that is widely grown for ornamental purposes is the Queen Palm (Arecastrum romanzoffianum). When ripe, its oily fruits are enjoyed by almost every species of parrot, large and small.