Ring-billed ? Gull (Larus delawarensis) # Obs. = 1 A subadult thought to be this species was recorded in Section 9. Arctic Tern Tern sp. # Obs. = 14 # Obs. = 86 Total =1-- Forty-four Sterna sp. were seen in Section 1 on 13 September. The sightings were groups of 3 to 17 birds heading strongly south. The three birds collected were Arctic Terns and quite surely the majority of the Sterna were this species. Sterna sp. were recorded in the northeast corner and then a large 200-mile gap was crossed (partly at night) in which no Sterna were recorded. The 44 Arctics appeared fairly suddenly at the extreme northwest corner of the Grid. I suspect the Sterna closest to the coast may have included or even been entirely Common Terns, S. hirundo. Xantus Murrelet (Endomychura hypoleuca) # Obs. = 3 All three birds were seen in the northeast areas. No other Alciás were seen in the Grid. Mourning Dove (Zenaidura macroura) # Obs. - 23 An increasingly regular element of the Grid avifauna, birds showed a fairly clear cut distribution paralleling the "distance-to-land-line" which runs through the Grid roughly along the heading 140°T (220°T). The offshore limiting distance is about 250-300 miles. Brown-headed Cowbird (Molothrus ater) # Obs. = 9 Immature Cowbirds appear to be regularly the commonest "pelagic" passerine. The distribution resembles that of Mourning Dove. No sightings were made in the four sections comprising the southwest corner. The fact that this species is parasitic and thusly fairly independent from Learned species typical behavior, is worth some reflection. Empidona sp. # Obs. = 1 (collected) Warbling Vireo # Obs. = 1 Warbler sp. # Obs. = 1 Vesper Sparrow # Obs. = 1 Sparrow sp. # Obs. = 3 (2 collected) Passerine sp, # Obs. = 2 Total 9