Information on Guinea-Bissau’s Important Bird Areas (IBAs) can be found in DODMAN, T., BARLOW, C., SÁ, J. & ROBERTSON, P. (2004).
The country checklist which includes a checklist for each IBA can be downloaded in a spreadsheet from this link: Guinea-Bissau checklist.
The 8 IBAs are as follows.
Arquipélago dos Bijagós
Ilha de Bolama - Rio Grande de Buba
Lagoas de Cufada
Rio Mansôa and Gêba estuary
Rio Tombali, Rio Cumbijã and Ilha de Melo
For further details, download the country IBAs from BirdLife International.