At sea, North Atlantic
1909.
August 1 [August 1, 1909]
(No 3)
and still more decidedly on the wing quills the primaries
being nearly black towards their tips. There were no
light markings anywhere above save on the upper tail coverts,
which were tipped rather broadly with white (the rump was
brown like the back), and on the hind neck which was
completely encircled, just below the occiput, by a collar of
pure white fully two inches in breadth. I called the attention of several of my
fellow passengers to this marking. All of them
agreed with me that it completely encircled the
neck which is not the case with P. major. The sides of the 
head and neck, with the entire under parts including the
breast and sides (but not, I think, the under tail coverts
which appeared to be dark colored at their tips), were
clear shining white as were the undersides of the wings
with the exception of their forward edges where, along the
the bony & fleshy parts to which the primaries & other
flight quills are attached ran a dark stripe extending
from the body quite to the end of the final joint
and one inch or more, in width. This formed a 
conspicuous marking, easily seen at a distance or more
than 100 yds. whenever the wing was thrown up in
flight. When this happened the extensive white under the
wing and the entirely white under parts made the bird
appear almost as white as a Gull and attracted ones
attention to it at great distances. It looked almost
equally white when resting on the water with the side
or breast turned towards the ship but when swimming
or gliding on set wings directly away from here it
was easily overlooked.
  Although the birds were colored not unlike Greater Shearwaters
their flight & behaviour seemed to me different, their size
& especially their spread of wing use. It may be they belonged
to the same species that I saw by tens of thousands in this
same stretch of ocean in June 1891 but failed to identify
then. I must refer to my journal of that trip to settle this point.
 On referring to my journal for 1891, I find that the birds
seen in large numbers on June 17 & 19 of that year were
like those observed on Aug. 1, 1909 in size, form, flight
and the broad collar of white around the neck but unlike the
latter birds they had white tipped primaries & no white on rump or upper tail coverts.