9 
Five of the six sooties were seen in the western sections (unusual). 
Densities have dropped since April. 
Cooks Petrel (Pterodroma cooki) 
Track 
Nontrack Total 
# Obs. 
56 
0 56 
# Collected 
11 
_ 0 
- 0 
+ * 4 * 
Ninety-four percent of the cooks were in the south section, predomi¬ 
nantly in the western half. Since the southern sections have not been 
fully covered since early April it is possible that this species has been 
in the Grid for some time, but I think not. The birds were all flying in 
a north or northwest direction and appeared regularly crossing the ship’s 
bow. This may be part of the populations observed off Southern Baja on 
EAC 13 in early June, just now reaching this latitude. The direction of 
travel could bring many birds off to the west of the Grid area before 
reaching 35° N. Birds were observed as singles and pairs, occasionally on 
the water. 
Track 
Nontrack 
Total 
White-rumped Storm Petrel 
# Obs. 
80 
1 
81 
Dark-rumped Storm Petrel 
# Obs. 
17 
4 
21 
Storm Petrel sp. 
# Obs. 
58 
81 
139 
Total 
155 
86 
241 
__ + (All Storm Petrel track) 
— -f* 
Over 46 percent of all Grid birds were Storm Petrels. While only 
some 9 percent of the total were recorded as dark-rumped, or all dark, 
the proportion was probably at least two times that; the lack of a white- 
rump being more difficult to ascertain than its presence. Distant or 
dubious birds were logged as "Storm Petrel sp." and doubtless include 
more dark birds than light. Unfavorable weather limited collecting and 
the subspecies present are not known. In addition to the dark form (5), 
2 white-rumped forms may be present. Several large-appearing birds with 
broad white rumps were seen in contrast to smaller birds with more re¬ 
stricted white. Birds were very abundant around Point Dogwood (linear 
density ca. 10.0 birds/mile) and common in the southeast section (linear 
density ca. 1.2 birds/mile). Ninety percent of the Storm Petrels were 
seen in the eastern section. On 23 July a dark-rumped bird with an ob¬ 
ject (Food ?) in its bill was noted being harassed by a white-rumped 
bird 125-150 feet above the water. They fluttered together for several 
seconds at that height, then returned to the surface and disappeared, the 
dark-rumped bird still possessing the object. 1 have not observed any 
phase of this sequence (except mutual fluttering) before. The height was 
exceptional;the wind speed was ca. 5 knots. 
