5 
different race or breeding population of “Cook's” Petrels than has been 
recorded in this area before. No comparison can be made with records 
from 1963 and 196 L. The variations in apparent coloration of the head, 
back and underwing under varying light and sea conditions make exceedingly 
difficult the separation of these races or species of Pterodroma . 
Bulwer* s Petrel (3) 
This species was not recorded in the grid in July. A few specimens 
collected outside the grid in August were molting heavily in the inner 
primaries, perhaps indicating that this species is beginning to disperse 
from some breeding areas. Individuals on Laysan Island were tending 
young chicks, however. Ihose in the grid may therefore represent unsuccessful 
breeders or non-breeders. 
Red-tailed Tropicbird (17) 
Slightly fewer were present than in July. All sightings were of 
individual birds. Five sightings were distributed randomly in the eastern 
i 
half of the grid. The remainder were obtained between the fourth and fifth 
legs with a alight concentration in the northwest leg between them. Only 
three immatures were recorded. 
White-tailed Tropicbird (3) 
This species remained low in numbers this month. Distribution was 
more random than in July, with two individuals being recorded in the 
a 
southern part of the grid near the fifth leg* 
% 
Ruddy Turnstone (l) 
This is the first shorebird record for the grid this year. This species 
has apparently begun its southward migration from breeding areas. The 
individual flew about the ship repeatedly, possibly to try to land. 
