5 
Great Frigatebird ( Fregata minor ) 
Lesser Frigatebird ( Fregata ariel ) 
frigatebird sp. 
No. of Birds Recorded 
No. of Birds Recorded 
Tt 
n 
tf 
10 
91 
21 
Great Frigatebirds were identified with certainty on 7 October just 
south of Oahu and on 13 October close to the equator. Unidentified frigate- 
birds noted on these two days were likely of that species. 
Lesser Frigatebirds were abundant only on 31 October just south of 
McKean and almost certainly were from the large colony present on the 
island at that time. In one large mixed feeding flock containing an 
estimated 85 Lesser Frigatebirds, no parasitism was noted and the frigates 
were feeding over surfacing tuna as intensively as the terns and boobies. 
Golden Plover No. of Birds Recorded: 10 
( Pluvialis dominica ) 
From one to a few birds were recorded each day between 7 and 11 
October. All birds were in nonbreeding plumage and at least a few were 
apparently immature birds which had no previous experience in trans¬ 
pacific flights. Two came aboard in an exhausted condition; both birds 
were exceedingly thin. 
Ruddy Turnstone No. of Birds Recorded: 2 
( Arenaria interpres ) 
The two birds were recorded on 8 October at l 8 0 22 'N. These made no 
attempt to land aboard the ship. 
Sooty Tern No. of Birds Recorded: 2 , 9^4 
( Sterna fuscata ) 
This species was common throughout much of the cruise and accounted 
for 59 percent of total birds recorded. Two broad areas of abundance 
were noted. On 8 and 9 October they were common in mixed flocks with 
Wedge-tails and petrels between l 8 ° 30 r N and 13 ° 15 T N. Immatures were 
frequently noted. On 13 October large feeding flocks were noted through¬ 
out the day T s observations from sunrise until 1100 . Two thousand one- 
hundred fifty-nine were seen during this period; most birds were feeding 
over shoaling tuna. Immatures were more abundant (estimated 10 percent) 
in these flocks than in the northern groups. This high density area 
ranged between the equator and 48 T south. As noted earlier, because of 
the large percentage of immatures in these flocks the birds were consid¬ 
ered not to have been from McKean. 
Common Noddy No. of Birds Recorded: 315 
( Anous stolidus ) 
Practically all birds (ca. 99 percent) were observed in mixed feeding 
flocks with Wedge-tails and Red-footed Boobies on 7 October from Oahu to 
