BIRDS OF LAYSAN AND THE LEEWARD ISLANDS. 
779 
a considerable distance from their nests, for it is reasonable to suppose that these 
were nesting' birds. 
The Albatross visited Bird Island again August 5 and remained four days in the 
vicinity. Although a landing might possibly have been made with considerable risk 
when we first arrived, the problem of leaving the island proved scarcely reassuring, 
so that we had to be content with again observing the birds from a distance. All 
the species seen during the first trip were again noted, with the exception of the 
albatrosses, both kinds of which were absent. The terns of the year were now full- 
fledged and flying about, the spotted plumage of the young of lunata and fuliginosa 
rendering them especially conspicuous. Young boobies were common also, and all 
stages of plumage between the immature and adult could be noted. Especially con- 
spicuous were the juvenile Sulct sula , which are wholly brown. Procelsterna saxa- 
tilis was still abundant. About 30 miles east of Bird Island we saw a white-tailed 
tropic bird ( Phaethon lepturus). This was the farthest west in the group that we 
noted the species, although about Kauai, Niihau, Oahu, Molokai, and Maui it was 
frequently observed. 
LIST OF SPECIES. 
LARIDA. 
Sterna fuliginosa. Sooty Tern. 
Sterna fuliginosa Gmel., Syst. Nat., I, ii, 1788, p.,605. 
While the Albatross was still some distance from Laysan we could easily distinguish great swarms 
of birds hovering over the island so as to form a veritable cloud. The greater number of this excited, 
screaming multitude were sooty terns. Their cries reach one at sea as a low murmur, but in the midst 
of a populous district the noise is simply deafening, and whenever we wandered among their “nests” 
we were obliged to suspend conversation. 
The sooty terns live in a great colony which extends along the upper half of the interior slope 
completely around the island, with only a few interruptions, and are thus found almost entirely among 
the bushy grass; on the west side the community extends nearly to the low bluff overlooking the sea. 
Their distribution on such a small island is only of interest when compared with that of a near-by related 
species, the two forms mutually agreeing to keep apart, though necessarily living in close proximity. 
Thus the white albatross or gony has preempted the greater part of the island and has relegated the 
black-footed albatross to the sand beaches. So the sooty tern, by virtue of greater numbers, has 
crowded the gray-backed tern ( Sterna lunata) toward the sea, where the latter occupies a narrow strip 
of island between the colonies of Sterna fuliginosa and the beaches and also a few scattered localities 
near the lagoon. It is much less numerous than S. fuliginosa, which has evidently gotten the best of 
the struggle, if struggle there has been. Sterna lunata begins to nest sooner than S. fuliginosa and 
presumably arrives earlier. 
The sooty terns nest in among the tall grass and the single egg is laid directly on the sand, with 
sometimes scarcely a hollow to suggest a nest. The eggs are placed very close together in many locali- 
ties — so close that it is sometimes difficult to progress and not walk on them. The birds are very loath 
at times to leave their nest, and scold soundly before finally slipping off. When at last driven, they 
limp away, dragging their wings in a painful manner, just as our own birds do. Thus, here, on a 
little island, is this firmly implanted instinct strongly in evidence, and practised where it can be of no 
possible advantage to the bird. Sometimes a dozen or more will struggle on ahead of the pedestrian, 
trampling over each other and crying incessantly, kicking eggs to the right and left in a mad endeavor 
to escape, while overhead their fellows keep up an incessant screaming. There is always a great cloud 
of these birds flying back and forth over the colony, even when no disturbing element is present. 
They seem to need the nervous excitement. Just at sunrise they are spontaneously most noisy, for 
then they apparently are returning from the sea, where I have heard them at various times during the 
night. The illustration of these terns flying gives a good idea of their actions on the wing. (Fig. 2. ) 
