These birds were common around our ship with an estimate of at least thirty individuals as we passed the Danjo Islands where they breed. They are members of the "Forster's" group which ranges from the Red Sea and Indian Ocean to the tropical western and central Pacific Ocean. Howell (2019) splits this group into a separate species called "Indo-Pacific Brown Booby" characterized by larger size, bigger bill, more extensive white underwing and darker upperparts. Males in breeding condition reportedly have a blue face and base of bill, but most of our birds had just a small blue spot in front of their eyes
