162 
TERNS 
vations are given in the Ibis as above. (See also a review of his paper 
in The Auk , 1906, p. 348.) 
62 . Xema sabini (Sab.). Sabine’s Gull. Ads. in summer . — Whole 
head and throat slate-color, bordered posteriorly by black, back and sides of 
neck, underparts, except throat, and slightly forked tail pure white; back 
and wings dark pearl-gray; secondaries tipped with white; first primary 
black, inner half of inner web, except at end, white; second to fourth pri- 
maries similar, but tipped with white; bill black, end yellow. Ads. in winter . — 
“Similar to the summer plumage, but the head and neck white, except 
occiput, nape, and auricular region, which are dull, dusky plumbeous” 
(B., B., and R.). Im . — Forehead and lores white, rest of upperparts ashy 
brown, feathers slightly tipped with whitish; tail white, broadly tipped with 
blackish; underparts white. L., 14'00; W., 10*50; T., 4*50; B., 95. 
Range . — Arctic regions to S. Am. Breeds on the coast of Alaska from 
Kuskokwim River to Norton Sound and in n. Mackenzie, n. Keewatin, 
and n. Greenland, and on Arctic islands of Europe and Asia; in migration 
on both coasts of U. S. and casual in the interior; winters in Peru. 
Long Island, A. V. two records; July; Oct. 
Nest, of grasses, etc., on the ground. Eggs, 2-5, deep olive (varying 
in intensity, however), rather indistinctly spotted or blotched with brown, 
1*78 x 1*26 (Ridgw.). Date, Hooker Bay, Alaska, July 1 (Thayer Coll.). 
This boreal species is of rare occurrence in the Northern United 
States, there being but three records for Massachusetts and the same 
number for New York. 
Subfamily Sternince. Terns . (Fig. 24.) 
The Terns number some fifty species, distributed throughout the 
world, ten being found in North America. They are more southern 
than the Gulls, only two species nesting north of Maine, in Eastern 
North America. They are also more migratory, none wintering on our 
coasts north of the Carolinas. 
Terns are littoral, not pelagic, and, although characteristic of our 
sea-coasts, like the Gulls, several species nest in the interior, the Black 
Tern breeding only on bodies of fresh water. Beautiful as pearls, 
graceful and active as Swallows, Terns are a constant delight to the eye. 
They capture their prey of small fish by darting toward it like a living 
arrow, plunging recklessly into the water, and, in some cases, swim- 
ming a few feet beneath the surface. When looking for food they usually 
fly with the bill pointed downward, a habit which will aid in distin- 
guishing them from the Gulls, whose bill is carried more nearly in a 
line with the body. 
Terns nest in colonies on islands and when disturbed are much 
bolder than most Gulls, hovering close overhead and swooping toward 
one fearlessly. The young are born covered with down, mottled in 
pattern like that of Gulls. This plumage is both countershaded and 
obliteratively marked; further proof of its protective value being 
furnished by the birds themselves, which, in obedience to the warning 
note of their parent, squat flat and become almost invisible so long as 
they remain motionless. Like the young of Gulls, young Terns are de- 
