Red-footed Booby 
* ; ' 
The increase from six birds of this species seen in March to 71 
seen in April is explained by two factors. First, a feeding flock of Uo 
was seen in the company of 200 Sooty Terns on the first day out of Oahu, 
and, second, 28 birds were seen within sight of Oahu on the last morning. 
Bile area was passed during the night on the March cruise. 
Great Frigatebird 
Only two birds of this species, both along the western edge of the 
grid area, were seen in April, indicating a very small but possibly regular 
occurrence in the western portions of the grid area in the spring. 
Sooty Tern 
Numbers of this species increased 3<$ from 1261 in March to 1633 in 
April. The difference can be accounted for by the nun*>ers seen during 
the last morning of the April cruise to the north of Oahu, the same area 
having been covered at night in March. Three density centers were foundj 
first, within 100 miles of Oahu, second, along the western side of the 
grid, and third, in the southeast corner. 
Noddy Tern 
All 16$ Noody Terns seen during the April cruise were seen within 
50 miles of Oahu where there is a large breeding colony. 
Hawaiian Noddy Tern 
All U20 of this species seen during the April cruise wore seen 
within ten miles of Hilo harbor. This species nests along the rocky cliffs 
of tiie coast of the island of Hawaii, 
