I've something of a weakness for expensive photography books, so I've had a good look round for parrot books, current and out of print, and drawn a complete blank. The Parrot Trust do calendars, and individual prints, but otherwise nothing. It's strange because there are dozens of books on raptors and a good number on pigeons/doves, sea birds, game birds, birds of paradise - so one would have expected at least a couple on parrots. There's a definite gap in the market for one.
Perhaps we all need to sponsor our resident photographic talent Copperarabian to go on a parrot photographing expedition...