Engbring, J. (1988). Field Guide to the Birds of Palau. Conservation Office and Bureau of Education: Koror, Palau.
Colonies Surveyed (4)
Palau EEZ -
Colony: Ngeruangel
Palau EEZ -
Colony: Ngeriungs
Palau EEZ -
Colony: Ngarapalas Island
Palau EEZ -
Colony: Elibel