Who's a pretty bird?!

My father Dug for Victory, as required by HM Government during the 39-45 spat with the Axis. As well as digging and planting up every inch of fertile soil around the house, front and back, he built two enormous greenhouses. Well, they seemed enormous to me as I was no more than two feet high at the time.
Much later, as the memory of beating the fascists faded and the disillusion with Attlee's lack of socialism grew, my father converted his two greenhouses into aviaries. In the larger one, he bred Budgerigars; in the smaller, Java Sparrows and Zebra Finches.
By this time, I had grown to six feet and had moreorless left home, so I had little to do with the aviaries, although I can remember being impressed by the range of colours of the budgies - red, yellow, green, blue and even magenta - and by the fecundity of the Java Sparrows and Zebra Finches, which were into an awesome repopulation programme.
"A bird imprisoned in a cage, puts all of Heaven in a rage", the poet said, and I am always saddened by the spectacle of caged birds in street markets in everywhere from Bangkok to Barcelona. But, at the same time, I have a niggling thought that it might be fun to have an aviary in my back garden.
I only know of one birder who is also a cagebird enthusiast. I wonder how many more there are?