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Leach’s Storm Petrel (5 4 6 nocturnal) 
white-rumped storm petrels (36 -f 7 nocturnal) 
White-rumped storm petrels have shown steady decline in numbers since 
April 1966 when the greatest numbers of wintering birds were present. 
Since Leach 1 s Storm Petrel (the dominant grid species) is presently on the 
breeding grounds in the Aleutians, grid birds likely represent immature 
birds* A few of the unidentified birds may be referable to Harcourt’s 
and/or Wilson 1 s Storm Petrels. Three specimens of Leach’s Storm Petrel 
were collected during diurnal operations and two were collected at night* 
Red-tailed Tropicbird (11+1 nocturnal) 
This species has been recorded in very low numbers on all previous 
cruises* The increase in grid sightings during the present cruise is considered 
to be directly correlated with the present increase in Howland Island breeding 
1 
birds* Two specimens were collected. 
White-tailed Tropicbird (1 -f $ nocturnal) 
Recorded in low numbers or absent on all cruises to date except for 
higher concentrations during October-November 1965* None were recorded 
during the April or May 1966 cruises* The 5 nocturnal sightings were 
recorded during the night of 11-12 July NE of Howland. 
Blue-faced Booby ( 390 +5 nocturnal) 
The greater numbers recorded during the present cruise can be attributed 
to increased cruise activity in the vicinity of Howland Island where the 
species is presently in the midst of a breeding cycle. Density figures 
