I was wondering, do any Zoos keep Quaker Parrots (also known as Monk Parakeets.) I'm asking because someone told me one to the ways to avoid getting your pet Quaker gassed by animal control if you are found to have one in a state where they are illegal is to give them to an educational institution e.g. a zoo. Frankly I'm not optimistic that anyone has them, due to their status as a feral "pest" in many places (though I don't agree with the pest label at all.) Its a shame that they have such a bad reputation. I really like the species. They are rather unique in the Parrot world, with their adaptability, social structure, and condo style nests that are unfortunately the cause of much of their persecution.
Not sure about the States, but they are pretty widely kept in Europe (around 100 Zootierliste entries). I'm guessing shipping one to Europe might be considered a non-starter on cost grounds, though.
As Maguari said, in Europe this species is kept and bred in many zoos and to check about the US I went to the US-Gallery and put a search for Monk parakeet. The result : Tracy Aviary John Ball Zoo Queens Zoo and Bronx Zoo I guess the species is not that common in American collections...