Welsh Mountain Zoo
The only UK zoo that I know has managed Pertinax's 'ideal' above, was Rode. Even their breeding pairs were allowed free flight in rotation; couldn't all be allowed out at once because of fighting. There are all sorts of issues with free-flying Macaws. Birdworld had to ground theirs because of complaints about the noise. At least one collection in the past had trouble with them ripping holes in wire netting and letting things out. Also, there is a fine line between keeping birds at liberty and 'releasing them to the wild' [which is illegal, and the reason why Edinburgh no longer has its long-established free-flying Night Herons, and almost nobody has free-flying Budgerigars {which make a fantastic show} any more]. Then of course, there's the Ruddy Duck, about which some of us could argue all night [or I would given half a chance]. While we're on the subject of free-flying species that have become naturalised [which we aren't really], why do people have a 'down' on Canada Geese? Hw can anything that weighs 14 pounds and is delicious, possibly be a nuisance?
Back to Macaws; I find flight-restriucted pasrrots nearly as offensive as flight-restricted Vultures.