since the light phase Red-foots had dark tails (subspecies vebsteri) and 
the Blue-faces had orange-colored bills (subspecies grant!) . 
Prigatebird (Fregata) 
Adult female Magnificent Frigatebirds are easily distinguished from 
♦ 
^emale Greats oy uhe color of the throat -- black, in the Magnificent, and 
gray in the Great. It is just as easy to distinguish between the adult 
naleo u-nese species at close range, for the male Magnificent has a 
light (slue) colored bill while the male Great Frigate has a dark (black) 
bill. This character should work 99 percent of the time. However, a male 
Great Inao has just molted into the adult plumage may retain the light 
* 
colored bill of the subadult for a .while. 
Arctic Tern (Sterna paradisea) 
“ — ■ i — ’ 
In September Arctic Terns were commonly encountered far from land 
generally moving southeast > but at other times in feeding flocks. Even 
^ravelmg groups were seen feeding. Evidently the migration of this 
species is leisurely. 
Sooty Tern ( Sterna fuscata) 
Sooty Terns were generally uncommon over the area (see FIGURE 16) 
being seen in numbers larger than a hundred on only four days. 
lV0 populations were evidently present in the area - a pre-nesting one 
ana a post-nesting one. near the Galapagos the flocks observed contained 
no young birds and the adults were in fresh plumage indicating the start 
of nesting cycle in this island group. On two other days when fairly large 
nameers oi cooties were seen immamures were present. These birds are very 
likely from Clipperton Island. 
■^n a ceptemoer I saw a flock of eight adult Booties sitting on the water. 
I have never 
before seen them on the water when immatures were not present 
