Joseph Foreshaw in the Third (revised) Edition of his book The Parrots of the World Page 419ff states for the Red-shouldered Macaw Ara nobilis
‘The Red-shouldered Macaw is the smallest of all macaws, and in the field it impressed me as being more like the Aratinga conures. The Hahn’s macaw Ara nobilis nobilis occurs in the Guianas, eastern Venezuela, and in Brazil north of the Amazon. A preference for partially open areas is reflected in its somewhat patchy distribution, especially north of the Amazon River where it is prevalent in marshlands and natural savannahs, but usually it is fairly common where it does occur.’
In my aviaries
In captivity this small green macaw has real character, although it is can be extremely noisy and so would not be suitable for sensitive neighbours in a suburban environment. They are similar in size to Sun conures and I keep them in aviaries 4500 long x 1200 high x 900 wide. The aviaries are fully partitioned and so birds have vocal but not visual contact with their neighbours. They do not appear to be chewers of the aviary wire or structure as long as you provide them with a regular supply of branches, swings and even toys. They are intellegent birds that need to be occupied, even in an aviary situation. With this in mind, I make my own swings / toys. I use rope tied in pieces of gum branches about 400mm long and hang them from the roof on a small length of chain. They seem to love hanging on upside down while trying to chew out the rope and / or the wood or just swing around while they decide what they will do next.. They are entertaining aviary subjects.