t 
5 
Herring Gull distribution which shows a fairly progressive trend to push 
southward Glaucous-wings show no discernible tendency to favor the 
northern sections of the Grid. 
Herring Gull Larus argentatus $ Obs. = 258 
The most constant and conspicuous element of the Grid fauna was 
groups of this gull following the ship. 
.6 
.5 
.1 
.5 
.3 
A 
TT Linear density” 
.1 
.4 
.1 
by section 
The northern two-thirds of the Grid has densities approximately 
double that of the southern third. Sixty-eight percent of the aged 
birds were adults. This is nearly the same as the previous survey 
(EGS 19 ; 63 percent), but both recent surveys have a much higher per¬ 
centage of adults than that recorded in late November (EGS $ 17 ; 3 
18 birds: 17 percent). The age distribution (adults' vs. nonadults) is 
not uniform over the Grid; adults are not as abundant in the southern 
third. 
Third Percent adults - 
North 73 
Center 79 
South 43 
Black-legged Kittiwake Rissa tridactyla $ Obs. = 153 
.17 .38 .28 
.17 M -36 
0 0 .05 
Birds per linear mile 
Total Grid numbers have increased regularly over the last three surveys: 
EGS # 
Total Obs 
Late Nov. 
17 
0 
Early Dec. 
18 
4 
Late Dec. 
19 
80 
Early Jan. 
20 
153 
This survey 1 s data suggest that the bulk of the Kittiwakes is 
pushing southeastward through the Grid concentrated in a fairly well- 
defined M tongue . 11 At the north end of the Grid the highest density is 
located in the center third; in the center latitudes the concentration 
is shifted to the two eastern thirds (V and W) and in the south latitudes 
the only section with Kittiwakes recorded is the easternmost (z) . Per¬ 
haps numbers increase again directly to the east of ’ Z 1 but no ooserva- 
tions were taken over this region. 
v 
