The Caspian Tern {stema caspia) 



By W. Leon Dawson 



Description. — Adult in spring: Top of head and nape uniform lustrous 

 black; upper parts pearl-gray, whitening somewhat on rump and posteriorly; 

 wing-quills not especially different, the silvery gray nearly concealing dusky on 

 exposed portions ; inner webs plain grayish dusky ; tail slightly forked for about 

 one-fifth of its length, — folded wings considerably exceeding; remaining plumage 

 white; bill very stout, — the depth at base being nearly equal to one-third the 

 length of culmen, — bright coral-red slightly tinged with dusky at tip ; feet and 

 legs black. Adult after the breeding season and in winter: Similar, but black 

 of crov/n speckled or streaked with dull white. Young: Black cap of adult 

 represented by spotting on top of head (on grayish white ground), increasing 

 in density until nearly uniform on hind head; above dull pearl gray, sparingly 

 spotted or barred with brownish dusky ; primaries darker than in adult ; tail pearl- 

 gray with dusky subterminal spots, or indistinct barring; remaining plumage 

 white, bill orange-red; feet brownish black. Length 20.00-23.00 (508-584.2) ; wing 

 16.25 (412.8) ; tail 5.00-6.50 (127.-165.1) ; bill 2.75 (69.9) ; depth of bill at base 

 .80-.95 (20.3-24.1) ; tarsus 1.80 (45.7). 



Recognition Marks. — Largest of the Terns; of conventional coloration, black- 

 capped, and mantled with pearly blue ; bill large, stout, bright red ; the stouter 

 bill presents the chief field difference from the Royal Tern {S. maxima), but this 

 bird is somewhat larger every way, and lacks the definite white on the inner web 

 of primaries. 



Nesting. — Nest, on the ground, usually in sand. Eggs, 2 or 3, buffy white 

 or greenish buff, spotted and blotched with chocolate and lilac. Av. size, 2.70 x 

 1.80 (68.6 x 45.7). 



General Range. — Nearly cosmopolitan; in North America breeding south- 

 ward to Virginia, Lake Michigan, Texas, Nevada and California. 



LITTLE can be said of the occurrence of this Tern within our borders, 

 except that it is a bird of striking appearance, easily recognizable because of its 

 large size. There is no reason yet to suppose that it breeds in Ohio, the few 

 specimens seen having been, in all probability, en route to or from more northern 

 breeding grounds. The Caspian Tern has a wide distribution both in this country 

 and in the Old World; but it is reckoned common only in restricted and widely 

 separated localities. 



Of the nesting of this species, Mr. Ridgway says : "Unlike most other Terns, 

 and conspicuously unlike the almost equally large Royal Tern {S. maxima), the 

 Caspian Tern appears to breed in isolated pairs instead of large colonies, its nest 

 being usually far removed from that of any other bird, and consisting merely of 

 a shallow depression scooped in the sand, in which its two eggs are laid, with 

 little if any lining, though a few grass, or sedge, blades or other vegetable sub- 

 stances are sometimes added. It is very bold in defense of its eggs or young, 

 darting impetuously at the intruder, uttering meanwhile hoarse barking or snarl- 

 ing cries." 



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