The Common Tern 



hundred feet. But loafing is really Forsters' forte. They will stand 

 around by the hour on fence-posts, in amiable listlessness, or they will 

 foregather with their fellows in measureless content upon some low-lying 

 mud-reef. Really, now, it rests the mind merely to recall these lazy 

 Lazzaroni. 



No. 287 



Common Tern 



A. O. U. No. 70. Sterna hirundo Linnaeus. 



Synonyms. — Wilson's Tern. Sea Swallow. 



Description. — Adult in summer: Top of head and nape uniform deep black; 

 back and wings pearl-gray; wing-quills dusky, more or less overlaid with silver, except 

 on outer web of outer primary; the inner half of inner webs sharply white, but not 

 reaching tip; rump, upper tail-coverts, and tail (basally and centrally) white; tail 

 deeply forked, the outer pair of feathers elongated and narrowly tapering, but not, 

 or barely, reaching the tips of closed wings; their outer webs abruptly grayish dusky, 

 contrasting with white of inner webs; the succeeding pair also similarly marked; under- 

 pays white, strongly tinged, except on throat, crissum, and wing-linings, with pale 

 pearl-gray or lavender-gray. Bill vermilion-red, blackening on tip; feet orange- 

 vermilion. Adult in winter: Similar, but black cap imperfect, invaded by white on 

 forehead and decreasingly on crown; underparts paler, or pure white. Bill and feet 

 not so bright. Young (in August): Forehead and lores ashy gray; region about 

 eyes, hind-crown, and nape leaden black; back, scapulars, and wings pearl-gray, each 

 feather tipped with brownish buff and mingled subterminally with brownish dusky, 

 forming a strong bar; upper tail-coverts and tail lighter pearl-gray, the central feathers 

 of the latter tipped with buffy; the anterior lesser wing-coverts bluish dusky, with 

 narrow ashy edgings; edge of wing and quills plumbeous-gray; underparts white. 

 Length 330.2-406.4 (13.00-16.00); wing 273 (10.75); tail 127-152. 4 (5.00-6.00); bill 

 35.7 (1.41), depth at angle 6.7 (.26); tarsus 20.3 (.80). 



Recognition Marks. — Little Hawk or Crow size; black cap; pearl-gray mantle; 

 deeply forked tail; extensive white, or pale grayish plumage; graceful flight. Known 

 from the preceding species by outer pair of tail-feathers dark on the outer instead of the 

 inner web; underparts not pure white in breeding season. Bill tipped with black as 

 distinguished from next species. 



Nesting. — Not known to breed in California. Nests: In colonies, on beach 

 shingle, or in grass of low islands, lined or not, with bits of bark, grass, etc. Eggs: 

 2 or 3, rarely 4; very variable in ground-color — olive-buff, greenish or pinkish olive-buff 

 to dark olive-buff, sharply spotted or small-blotched with black or brownish black 

 with self-tones of bister and much undershell marking of violet-gray or pale violet-gray. 

 Av. of 30 sets from Cobb's Island in the M. C. O. coll.: 41.9 x 30.8 (1.65 x 1.21); index 

 73. Season: June; one brood. 



General Range. — Nearly cosmopolitan, but breeding only in temperate portions 

 of Northern Hemisphere. In America breeds from Great Slave Lake, central Keewatin, 



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