Well, you interest area is wide open as precious little is out there in any form, much less book or peer reviewed form.
You probably know about Project Bird Watch Indonesian Parrot Project, but perhaps you have yet to check their library. An especially interesting article is one which examines the status of Seram Cockatoos. The workers used both linear transects and variable circular plots as their basic framework. Although I am not comfortable with either their observational criteria or the DISTANCE software assumptions which they used for analysis, at least they made a valiant effort. Here is the link to the articles section.
http://www.indonesian-parrot-project.org/articles1.html
If you are going to look at management of island populations, you will really need to include most or all of the lesser suphur brested and some of the greater sulphur crested species as they are found from Australia into New Guinea, Palm which are also found in off shore Australian islands and New Guinea, Red Tailed Blacks found on off shore islands, Glossys found on Kangaroo Island, U2s and G2s found in Indonesia, and Blue Eyed Toos found in the Bismarck Archipelago.
I would suggest that you look at the Lexicon of Parrots as one starting point to develop distribution maps.
http://www.parrot-lexicon.com/
You are likely to find more material on those cockatoos endemic to Australia, particularly regarding argicultural and development issues.
You may have a bit more success if you can enlist the help of people in the professional ornithological societies for detailed searches of their databases of house publications which often don't seem to make it into other research databases. Even so, cockatoos comprise such a small number of birds in remote areas that comparatively little has been written about them inclusively, much less by individual species.
Good luck. Let me know if I can be of more help.
Carolyn et al.
