BIRDS OF LAYSAN AND THE LEEWARD ISLANDS. 
777 
We left the vicinity of the shoal on the evening of May 29, and arrived near 
Necker Island (latitude 23° 35' N., longitude 164° 41' W.) the afternoon of the next 
day. Necker Island is a dark, forbidding, rather precipitous rock of volcanic origin, 
attaining a height of 300 feet. It is about seven-tenths of a mile long and is shaped 
like a rude fishhook, the shaft extend nearly east and west, the barb being a rugged 
peninsula pointing toward the northeast and inclosing a rocky and turbulent cove. 
The island is entirely composed of lava, mostly of a sooty gray or black, with 
streaks of dull dark-red through it. The sides of the rock, though steep, are intri- 
cately terraced, especially on the northeast point, where there is a series of shelves 
and all sorts of knobs and crannies, making the place ideally fitted for the occupation 
of birds. The succession of terraces is curious and appears almost artificial in places. 
Each shelf, from 1 to 10 feet wide, is succeeded by a slightly overhanging rise. These 
perpendicular steps are full of bowl-like hollows, deep, irregular crevices, and jutting 
knobs, and form excellent nesting-places for Gygis alba kittlitzi , Procelsterna saxatilis, 
Sterna lunata , Puffinus cuneatus , Bulweria bulweri, and Phaethon rubricauda. 
Out on the open shelves one finds other birds, such as Sterna fuliginosa, Anous 
stolidus, Sula cyanojps , Sida sula, and Diomedea immutabilis. The wider shelves of 
the island are sparsely covered with a fleshy-stemmed, 3 'ellow-flowered portulaca 
(Portulaca lutea), and the summit is rather plentifully grown over with Chenojpodium 
sandwicheum bushes, on which large colonies of Sida gjiscator and Fregata aquila 
were nesting at the time of our visit. The bright red, puffed-out gular sacs of the 
male frigate birds could be discerned with a glass from some distance at sea, shining 
out like great red fruits among the green foliage of the summit. 
We landed in a little cove on the north side of the island, through the skillful 
management of Mr. A. B. Alexander. The I’ocks rise abruptly out of the water, 
and the whole north side is very precipitous. A shelf of rock, just above the surf, 
makes it possible to go about without difficulty. We found birds in great abundance 
and were fortunate to meet almost at once the diminutive pearly gray tern which we 
had seen at French Frigate Shoals. This species turned out to be new, ana I have 
called it Procelsterna saxatilis a because it always lays its egg in hollows among the 
rocks. Its nearest relative, Procelsterna cinerea , is an inhabitant of Australian and 
New Zealand seas. We were also so fortunate as to discover the eggs and downy 
chick, and an immature bird in full juvenal plumage. 
It proved very interesting to compare the nesting sites of the same species on 
two such different islands as Necker and Laysan — the one high, steep, and rocky, the 
other low, flat, and sandy. Gygis alba kittlitzi , here much more common than on 
Laysan, still clung to the rocks. Sterna fidiginosa chose the softest spots, where an 
accumulation of soil had collected on the shelves. Both Sida gnscator and Fregata 
aquila , as a rule, nested in the bushes on the summit of the island, just as on Laysan. 
But Puffinus cuneatus and Phaethon rubricauda have been obliged to seek crevices in 
rocks. They seem as prosperous, however, as on Laysan amid the sand. Birds are 
abundant and most of the available space is occupied. As on Laysan, so here the sooty 
tern is the most plentiful species, while the black-footed albatross is probably the least 
abundant of the breeding forms. One interesting find on this island was the eggs of 
Bulweria bulweri , a gentle, retiring little petrel of rather nocturnal proclivities. 
Several of the party who climbed to the summit of the rock, not without some 
Proc.U. S. Nat. Mus., xxvi, p. 659. 
