4. evident in some of the individual species,i.e., Tahiti Petrel and Juan Fernandez Petrel. Why this relationship should exist cannot be determined at present. The best correlation between birds and the pelagic environment seems to be a negative one - where there is a scarcity of food and nutrients in the water there are few birds. Such an area was found this trip between 15°S and 20°S, where only an average of 11.3 birds per day were seen. Probable Land Bases of Species Seen in the Study Area The following table is an attempt to show the origin of the birds in the study area. For most of the species this is highly speculative but in some cases (e.g., Black-footed Albatross) it is definite because these areas are the only places where the species nest. Species Seen Only off California (North American) Arctic Loon Cassin's Auklet Brown Pelican Ring-billed Gull Cormorant (sp.) Heermann's Gull Surf Scoter Black-legged Kittiwake Western Gull Royal Tern North and Central American Coast Wedge-tailed Shearwater(dark phase)+ Blue-faced Booby + Manx Shearwater + Pomarine Jaeger + Leach's Storm Petrel + Long-tailed Jaeger + Red-billed Tropicbird Herring Gull Red-footed Booby + California Gull Red-Phalarope + Sooty Tern + Hawaiian Islands including Leewards Black-footed Albatross + Laysan Albatross Wedge-tailed Shearwater (light phase) + Red-tailed Tropicbird +