Is this something like that bonsai kitten idea where if you put an animal in a small cage it won't get bigger? This duiker cage seems like it. Not fit to be graced with the word exhibit!
Poor animal barely has a life really- more just an existence in such a tiny space. Especially considering that it is an animal of deep shade being kept right next to a window that I image can make things quite hot in summer.
In all seriousness, did the owner get a parrot cage and then just stuff whatever they could get hold of into it? That's certainly what it seems like.
Is there any sort of animal rights body in America that has the power to put an end to this sort of animal attraction (zoo is too grand a word to use for what is essentially someone's living trophy collection). Can the American version of the RSPCA (Is it ASPCA?) confiscate animals from an attraction in the same way that they'd be able to do it to a private individual?