Several people have asked me:
There is no book, only this online Encyclopedia of Parrots – and it is free to use!
Information in a book quickly gets outdated as new species are discovered, old species are reclassified and new information from recent studies are published.
It is much easier to maintain an up-to-date encyclopedia online so currently I have no plan of making this encyclopedia into a physical book. Maybe a downloadable PDF sometimes in the future, who knows…
Also, I keep getting more and more photos of parrots – both new species but also better photos of species already included in the encyclopedia, so I keep updating the pages.