640 GULL-BILLED TERN. 
larger and paler race, which breeds in Australia and was distinguished 
by Gould as S. macrotarsa. In America the Gull-billed Tern nests 
along the east coast from New Jersey to Texas, as well as in the 
Bahamas, Cuba &c., and probably on the back-waters near Santa 
Catarina in Brazil; while it ranges as far south as Patagonia. On 
the Pacific side the late Mr. Salvin obtained it in Guatemala. 
A slight hollow scratched in the earth or sand, lined with a few 
fragments of sea-weed or dried grass, serves as the receptacle for the 
eggs, which are 2 or 3 in number; their ground-colour is usually 
pale buff—occasionally of a greenish tint which soon fades— 
blotched and spotted with several shades of brown: measurements 
2 by 14 in. During the breeding-season the note resembles the 
syllables che-éh, but at other times the bird utters a laughing af, af, 
af, like a Gull. In Ceylon Col. Legge found it feeding on frogs, 
crabs and fish ; in Egypt Von Heuglin observed it darting into the 
dense smoke of a prairie fire in pursuit of locusts ; and in Algeria 
Salvin noticed it hovering over grass fields, and pouncing upon 
grasshoppers and beetles ; it also captures many species of insects 
on the wing. Its flight is graceful but not very rapid, the long wings 
being plied with steady measured strokes. 
The adult in summer has the forehead, crown and nape jet black ; 
upper parts pearl-grey, except where the frosting has been rubbed off 
the primaries, which are then darker, especially on the edges of the 
inner webs ; under-parts white ; bill black, very stout and strong ; 
legs and feet black, with a tinge of red. Length 15 in. (bill 1-9), 
wing 12°5 in. In winter the head is white, with ash-grey streaks, 
some of which unite and form patches before and behind the eye 
and on the ear-coverts. The young bird is mottled and striped with 
brown, tinged with buff on the upper parts, while the bill and legs 
are brown ; and even in the second year, when breeding begins, the 
latter are still livid. 
This species occupies a position between the Marsh- and the 
typical Terns. The toes are almost as fully webbed as in the true 
Sea-Terns ; while the tail is short, and the lateral feathers are slightly 
rounded, though more pointed than in the Marsh-Terns. The bill 
is remarkably robust and obtuse; and the tarsus is proportionately 
longer than in any other species. For these reasons the bird has 
justifiably been made the type of the genus Ge/ochelidon, which I 
have accepted (Cat. Birds Brit. Mus., xxv, p. 4 and p. 25); but, 
inasmuch as genera are matters of convenience, I do not lay stress 
upon its use in the present work. 
