SOUTHERN PELAGIC: 939 miles and 95*5 hours of observations were completed 
in this area. Eighteen species were recorded. Collared Petrels were the 
most abundant and wide spread species observed, although White-throated 
and Juan Eernandez Petrels were close seconds. Average density was 0.33* 
BSM, the greatest numbers occurring in the eastern section where large 
numbers of unidentified storm petrels were recorded. The effects of the 
Peru Current and the Galapagos Archipelago were noticable in the eastern 
section where water temperatures were lower and such species as Swallow¬ 
tailed Gull and Dark-rumped Petrel were foipid. Other species (eg. Wedge¬ 
tailed Shearwater and Juan Fernandez Petrel) were restricted to the 
warmer waters of the western section. TABLE 5 shows the distribution and 
comparative abundance of birds within this area. 
TABLE 5 
DISTRIBUTION AND ABUNDANCE OF BIRDS WITHIN SOUTHERN PELAGIC WATERS 
Species _ . West Half East Half Total Birds Birds/Hour 
Juan Fernandez Petrel 
35 
0 
35 
0.4 
White Tern 
3 
0 
3 
-0.05 
Wilson/Elliot Petrel 
4 
0 
4 
-0.05 
Wedge-tailed Shearwater 
3 
0 
3 
-0.05 
Black-winged Petrel 
1 
0 
1 
-0.05 
Cook Petrel 
1 
0 
l 
-0.05 
Red-tailed Tropicbird 
1 
0 
1 
-0.05 
Collared Petrel 
33 
16 
49 
0.5 
Harcourt Petrel 
20 
16 
36 
0.4 
White-throated Petrel 
6 
27 
33 
0.3 
Murphy Petrel 
0 
1 ? 
l? 
- 0.05 
White-bellied Petrel 
0 
1 
1 
-0.05 
Swallow-tailed Gull 
0 
1 
1 
-0.05 
Dark-rumped Petrel 
0 
2 
2 
-0.05 
Sooty Tern 
0 
2 
2 
-0.05 
Soccorro Petrel 
0 
11 
11 
0.1 
Leach Petrel 
0 
19 
19 
0.2 
Of the three pelagic areas discussed above, the Countercurrent had, 
by far, the largest concentration of £>ifds and the greatest variety of 
species. This was particularly true at its* edges (See FIGURE 2). In 
the western section birds were most concentrated at the southern 
boundary, which was better defined in the oceanographic samples. This 
was the area of its convergence with the South Equatorial Current and 
the large avian density may be related to the mixing of waters in this 
area. In the eastern section greatest density was found at the northern 
edge, possibly due to the farther northward penetration of the colder 
waters of the Peru Current and also to the northward deflection and 
diffusion of the Countercurrent. It is also apparent that the middle 
section of the countercurrent had a greater density then either the 
Northern Pelagic Waters or the Southern Pelagic Waters. 
