T,is 
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SMITHSONIAN GRID Survey No. 27 
April 1966 
Observations were made in Smithsonian Grid No. 1 from 1-5 April, 1966. 
The Smithsonian Party consisted of Robert DeLong, Paul Woodward, and Richard 
Maze. Normal grid procedure was followed with the exception that the eastern¬ 
most leg was not included. Continuous observations were made throughout the 
grid. During diurnal periods 552 miles were traveled in 53#5 hours* during 
nocturnal periods 526 miles were traveled in 48.7 hours. 
Moderate to heavy seas and accompanying strong northeast winds made 
observing difficult. Due to these conditions many birds were undoubtably 
missed, especially shearwaters and petrels. 
During diurnal observations 1359 birds of fourteen species were recorded. 
This total represents a 67% increase over last month. Sooty Terns numbering 
1231 accounted for 91% of the total. Procellarids accounted for- 7*4%iof the 
total. Twenty-seven flocks were seen in diUmal periods. They accounted for 
1182 birds (or 87%)of the total. The flocks consisted almost entirely of 
Sooty Terns. Forty-eight birds—43 of them Sooty Terns-were recorded 
during night watches. 
The following changes were noted from March: Shearwaters-Petrels increased 
188%$ Terns increased 65%$ Tropicbirds did not change$ Boobies decreased 83%$ 
Frigatebirds decreased 100%$ Storm Petrels increased 100%. In addition six 
species recorded last month were not seen this month. The lack of Bulwer*s 
Petrels and frigatebirds, and the great reduction in the number of Red-footed 
Boobies is noteworthy. These species may be concentrated around Johnston Atoll 
and not ranging far out to sea. Five new species were seen this month including 
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