$Fregetta tropica melanoleuca Jouanin & Mougin,1979,in Mayr & Cottrell(eds.),Checklist of the Birds of the World,2nd ed.,1,p.108.
Marine and highly pelagic,rarely approaching land except near colonies.Occurs in tropical waters with high salinity.Breeds on offshore islands or stacks,generally among boulder scree or on grassy slopes,up to 450m above sea level.
"Latter part of summer, starting Jan or before." (HBW,1,p.268)
Apparently disperses north to lower latitudes,but does not reach as far north as F.tropica, nowhere crossing the equator in Pacific and Atlantic Oceans. In Indian Ocean, only in.Southwest.