792 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
While we were on the island the birds sat in pairs all day near the entrance to their homes, or if the 
sun grew too warm retired a short way into the tunnel, where they kept up an almost constant cooing. 
Not infrequently one will observe the shearwaters cleaning out old burrows or in the act of 
lengthening them. I saw but one tunnel newly started, so that the number of yearly visitants seems 
to keep fairly constant. In digging the birds scratch with bill and feet, and with the same imple- 
ments shove the loose sand and soil under their bodies, when they kick it in little jets far out behind. 
As they remove the sand they lie first on one side and work a foot and then shift to the other. One 
is sometimes startled, while standing quietly among the bushes, by being suddenly beset with little 
showers of sand, which on closer inspection are found to originate with some shearwater toiling into 
the earth. In their search for nesting sites they do not hesitate to wedge themselves into all sorts of 
places, apparently without thought of escape, but we never found any birds actually trapped. The 
burrows enter the ground at a slant and then become horizontal. They are at least 3 feet long and 
often very much deeper. Rarely they are only about 2 feet, and these are new, while the longer ones 
are the older, having been dug.out by successive tenants from year to year. The birds had not yet 
begun to lay, and do not till early in June, according to the testimony of Mr. Schlemmer. 
Their note varies. When undisturbed they utter a dove-like khoo-who, which changes to a loud 
khoo-ow' as they grow excited, and finally at the height of their enthusiasm one hears only a yow-ow' 
or oo-ow', quite like the nocturnal serenade of cats. It seems to be a courting song, but is decidedly 
unmusical. 
A comparatively few at this season fly abroad during the day, but after dark they begin to move 
about more, and one moonlight night we found them very active and owl-like in their flight. At sea 
they are expert fliers, sailing with immovable wings rapidly and readily close over the waves, as well 
against as with the wind, and they can go across the breeze much more easily than can the albatross. 
We met this species off the French Frigate Shoals, and on Necker found it nesting, but, as on 
Laysan, there were no eggs. The birds nest in hollow cavities of the rock, where they sit facing the 
wall, and when disturbed coo and yowl in familiar fashion. I suppose the uau {oo-ow') of the native 
name is in imitation of the cry. N o nest proper was found in any of these little caves ; only a few twigs, 
feathers, and old bones scattered about. 
The species was noted at Bird Island, where a number flew aboard, attracted by the glare of deck 
lights. Stomachs of these birds contained the hard parts of small cephalopods (squid, octopus, and 
the like). It was seen constantly at sea throughout the main Hawaiian group. It is known to breed 
on Kauai. « This shearwater ranges west across the north Pacific Ocean to Volcano Island, south of 
Japan, 6 Krusenstern Island, Sulphur Island, Bonin Island. 
We kept four males and four females of this species. One male from Bird Island and one from 
Laysan have the lower parts immaculate, except for a faint smoke gray or brownish gray shading and 
barring of feathers on sides and flanks. In all the other specimens (3 males and 3 females) the deep 
brownish gray of the sides of the neck encroach in varying degrees onto the throat and jugulum and 
that of the sides and flanks onto the breast and abdomen. In two specimens this shade extends 
entirely across the throat, the feathers of the sides of neck being terminally mouse gray, edged with 
white, while those of the throat are white with one or two irregular bars of gray. The effect produced 
is a delicate vermiculation of the jugulum and a coarser herring-bone spotting of the throat. The 
flanks are dark in these six specimens, and in all there is a greater or less vermiculate barring of 
abdomen. A breeding female from Laysan has a very fine, dust-like spotting scattered over nearly 
all the abdomen. There is a slight variation in the bills. (Fig. 29. ) 
Puffinus nativitatis. Christmas Island Shearwater. 
Puffinus nativitatis Streets, Bull-. U. S. Nat. Mus., No. 7, 1877, p. 29. 
The Christmas Island shearwaters were nesting on Laysan at the time of our visit. They are 
distributed here and there over the island, usually in the domain of JEstrelata hypoleuca, but not 
infrequently we found them among the wedge-tailed shearwaters, and again on low sand bluffs 
overlooking the sea. It is entirely probable that the species is much more abundant than they seem 
to be, for they are decidedly retiring in their habits, and prefer to lay their single egg under the 
densest bushes away from the hot sun. For this reason alone a large proportion would naturally 
escape detection. 
iStejneger, Proc. U. S. N. M. 1888, p. 93. 
i>Salvin, Cat. B. B. Mus., xxv, 1896, p. 371. 
