Vol ig x 6 in l Anthony on ike Black-vented Skearzvater. 2 27 



established fly lines 1 as do the three species of Puffinus ; even 

 when flying fifty miles or more from land the first flock that 

 passes will, with almost absolute certainty, mark the line which 

 the next will follow, even though they be an hour behind. And 

 I have long since discovered that in order to secure specimens 

 of these shy species the boat must be placed in their fly lines. 

 A flock will, on encountering a skiff, directly in their path, 

 either divide and pass on either side or all swerve slightly to 

 one side, immediately resuming their line of travel in either case. 

 At times, however, they are easily turned from their course. 



On January 23, I was drifting in a skiff off Point Loma, watch- 

 ing the Black^vented Shearwaters which were flying south along 

 the western edge of an extensive bed of kelp. A garbage scow 

 had sailed out through the kelp an hour before, leaving a broad 

 oily 'slick 1 a hundred yards in width, extending two or three miles 

 westward, at right angles to the course taken by the Shearwaters, 

 which were passing in small flocks of four or five to a dozen every 

 ten or fifteen minutes. Each flock turned sharply about when 

 at a distance of a hundred yards from the oily water, and keeping 

 at about that distance and to the windward, hurried on toward the 

 west. Not one bird did I see cross contaminated water. I could 

 detect no odor from the oil nor could the birds, had any existed, 

 for they were flying down the wind. 



I have never seen Black-vented Shearwaters pay any attention 

 to bait or refuse thrown from the ship's galley, though Dark- 

 bodied, Pink-footed, and Slender-billed Shearwaters will light to 

 pick up floating garbage. 



Though all of our Shearwaters prefer to keep rather well off 

 shore, they will at times follow schools of smail fish into shoal 

 water. I once saw a flock of one or two hundred Black-vented 

 Shearwaters feeding in the surf at Cape Colnett. Hovering over 

 the advancing breaker they followed it to th.e beach, returning to 

 meet the next, plunging repeatedly into its foamy crest for some 

 species of small fish. They evidently did not feel at home so 

 near land, for after a few minutes fishing they hurried out to sea 

 again. 



1 In this connection see Mackay on ' Fly Lines,' Auk, Vol. X, p. 245. 



