the immature birds in the flocks. The frigates in the southern areas 
could be from the Marquesas (or Tuamotus) which was the nearest land. 
Perhaps the birds north of the equator were from the Line Islands and 
consequently had no frigates associated with them. The islands off 
the American coast that have Sooty Terns are another possible source 
of these birds, but they have a spring breeding cycle which would not 
account for the immatures in the flocks, especially since the direction 
of flight would indicate that they would be returning to the islands 
to nest. All of this is of course, pure conjecture and must await 
further work in the area before any definite statements can be made. 
Fairy Tern ( Gygis alba ) 
Fairy Terns were found in fair numbers south of the equator and 
only occasionally north of it (see figure 19)* The data from this 
grip indicate that this species wanders great distances from land, as 
one was seen well over 1,000 miles from the nearest land, and they were 
common at the 600 mile mark. 
Cetaceans 
Figure k_ shows the numbers of mammals seen per day during the 
trip. They were most common near the equator and in the California 
Current, but were almost totally absent in the Southern Hemisphere. 
