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Whlte-throated Storm Petrel 
( Nesofregetta albigularls ) 
Expecting Fregetta grallaria, I was quite surprised to find 
Nesofregetta the only white-bellied Storm Petrel present along the 
southern equatorial counter-current. When taken into consideration 
the scarcity with which this species is recorded in close proximity 
to nesting colonies> I must conclude that Nesofregetta is an 
abundant bird of the counter currents transversed on this tripl Birds 
south of the equator are probably of Marquesas origin. It.is quite 
possible that birds north of the equator are from the Christmas Island 
oopulation. • 
Least Petrel 
( Halocyptena microsoma ) 
This species was recorded regularly in the seas surrounding the 
Revilla-Gigedos Islands and to the east. The majority of the population 
winters in the seas around Panama along with the Black Petrel ( Oceanodroma 
melania) which was totally lacking from the area covered in this cruise. 
Red-billed Tropicbird 
( Phaethon aethereus ) 
Red-billed Tropicbirds were found in proximity to the 
coast, or islands which they breed on. Unlike its larger relative, 
the Red-tailed Tropicbird, it was very rarely attracted to the ship. 
Red-tailed Tropicbird 
( Phaethon rubricauda ) 
This species was found commonly in the Southern Hemisphere, 
regularly around Clipperton Island and occasionally in other areas 
with the exception of area ”A”. The origin of birds observed 
throughout the trip is quite difficult to determine. It^^may be safe 
to say that Southern Hemisphere birds were from the Marquesas, but 
/ this would have to be proven. Birds around ^Clipperton Island indicate previously 
unrecorded breeding population may be present but this is unconfirmed. If 
there isn’t a breeding population in this area, the birds are probably 
from the Galapagos - 1,200 miles, or the Hawaiian leewards - 3,500 
miles awayI 
Blue-footed Booby 
( Sula nebouxii ) 
Blue-foots were encountered only rarely. They evidently do not 
wander far from their breeding islands. 
