65 
To the west of the desert separating the Phoenix-Samoa fauna from 
the Fiji fauna (see south pelagic discussion) wedge-tails became very 
abundant, easily the dominant species. The peak abundance was around the 
Isles Horne, an area rich in reefs. Numbers declined toward the main 
Fiji Islands. The land origin of such a large concentration is not at 
all clear. 
North of the 5° N. area birds are few until the light-phase popula¬ 
tion increases at 15° to 20° N. (See also Graphs 10 and $k). Except for 
around Christmas Island, the Line Island waters produced only scattered 
individuals. 
New Zealand Shearwater # Recorded = 1 
Puffinus bulleri 
The single positive sighting was made on 7 April, northeast of Samoa 
where wedge-tails were found abundantly. Another tentative identification 
was made between Jarvis and Malden. As will be noted in the case of sooty/ 
slender-bills, I suspect there is a tendency for some of the migrant shear¬ 
water species of the Pacific southwest to pass through the P03SP study 
area in the sections between Samoa and the southern Line Islands. 
• 
Sooty Shearwater # Obs. = 108 
Puffinus griseug 
Slender-billed Shearwater # Obs. = 6 
Puffinus tenuirostris 
% 
Sooty or Slender-billed Shearwater # Obs. = 130 
Total 244 
(10$ of S.I.C. 18 Shearwater/Petrels) 
No sooties or slender-bills were seen during SIC 17 (January- 
February). Birds (5) first appeared on l4 March just north of Kingmau- 
Palmyra. No birds were recorded from Palmyra to Christmas but on 25 
March, south of Christmas a high density of about 0.5 birds per linear 
mile was recorded. Numbers remained regular and fairly high throughout 
the southeast sections (Lines to Samoa) with the linear density a sub¬ 
stantial 0.1 birds per linear mile. Three-fourths of the total sightings 
were made over this track (Christmas to Samoa). No birds were recorded 
between Samoa and the Grid area, and numbers in the north pelagic areas 
were fairly low. More than 80 percent of the 59 birds in the north 
pelagic region were recorded in the 5° N. section. The remainder were 
scattered sightings to the north. 
Much of the confusion regarding these two forms is a result of a 
general reluctance to trust the field identification characteristics 
separating the two species, and consequently lumping the two and treating 
them as one group. For the most part the situation is no more difficult 
than the parallel problem between Sooty and Gray-backed Terns. Tnau is, 
gray-backs doubtless go unrecorded in some Sooty Tern flocks because the 
low occurrence of gray-backs makes it useless to record sooty/gray-Dacks 
