North Atlantic
Voyage from Liverpool to Boston - Gulf Stream waters
1911.
Aug. 6
(No 3)
[August 6, 1911]

Flight of Procellaria pelagica

bound, as it were, straight upward to a height of 8 or 10 feet
above the crests of the waves, repeating this action several times
in succession and reminding me of the similar but more pronounced
and gracefully rhythmical upward and downward swoops of Manx
Shearwater. There were times when these small Petrels seemed to
me to fly as rapidly, over wide areas, as I have ever seen
the big British Swifts fly. The longer I watched them the
more convinced I became that they could not be Wilson's Petrels
and that they must be Stormy Petrels (Procellaria pelagica). Dr. Allen,
however, was inclined to refer them all to Oceanites oceanica
failing to see that there was anything peculiar in this flight
although he admitted that a few of them did look rather too
small for that species. I might perhaps have been tempted to
agree with him had I not seen, under precisely similar
conditions, the then larger and slower flying birds, less than 
an hour before lesser ones began to appear.