Preliminary Report 
► 
Northern Grid Survey No. 38 
21 July 1968 
Northern Grid 
Luring 21 July 1968 , Smithsonian personnel (R. S. Crossin, R. B. 
Clapp, and C. D. Hackman) conducted at-sea observations through the 
Northern Grid on the U.S.C.G.C. PLANETKEE. 
Observations were somewhat hindered by rough seas and intermittent 
rain squalls throughout the day; No nocturnal observations were made. 
Sightings consisted primarily of single individuals of the shearwater/ 
petrel group, notably Juan Hernandez, White-necked and Black-winged Petrels. 
Five Wedge-tailed Shearwaters were seen, four of these dark phase. One 
small feeding flock of 15 Sooty Terns were recorded late in the afternoon; 
an immature was recorded earlier. 
TABLE 1 , Summary of Northern Grid Observations, 21 July 1968. 
# hours miles # birds birds/lin.mile 
21 July 12.8 141 53 0T3B 
TABLE 2 . Birds Recorded in the Northern Grid, 21 July 1968. 
Wedge-tailed Shearwater 5 
Juan Fernandez Petrel 8 
White-necked Petrel 3 
Juan Fernandez/white-necked 2 
Black-winged Petrel 12 
Pterodroma sp. -4 
White-tailed Tropicbird 1 
Sooty Tern 17 
Fairy Tern 1 
TABLE 3 . Comp ition of birds by species groups 
in the Northern Grid, 21 July 1968. 
mile 
jo of total birds 
Shearwater/Petrel 
34 
Tropicbird 
1 
Tern 
18 
0.12 
64 
o.oo4 
2 
0.042 
34 
