The Arctic Tern 



along our coast, in limited numbers, and in this my experience concurs. 

 Our uncertainty is heightened by the fact that no nesting colony of the 

 species has ever been reported from the Pacific Slope, not even from 

 Alaska; and it would appear probable that birds nesting in the Canadian 

 interior, as at Great Slave Lake, are finding their way to our coast in 

 increasing numbers. There are spring as well as fall records for Califor- 

 nia, but no breeding nor winter records. 



No. 288 



Arctic Tern 



A. O. U. No. 71. Sterna paradisaea Briinnich. 



Synonyms. — Paradise Tern. Crimson-billed Tern. Portland Tern. 



Description. — Adult in breeding plumage: Wings, tail, and black of head much 

 as in preceding; mantle deep pearl-gray; lower rump and upper tail-coverts pure white; 

 underparts deep pearl-gray tinged with lavender, clearing to white only on lining of 

 wings, lower tail-coverts, and on sides of head adjacent to black cap. Bill bright 

 carmine, sometimes faintly tipped with blackish; feet rich carmine. Adult in winter 

 plumage: Similar, but underparts white; forehead, fore-crown, and lores, anteriorly, 

 white; crown mixed black and white, and remaining black of cap a little broken. Bill 

 black or with mere traces of red. Immature: Similar to adult in winter and much as 

 in preceding species, but dusky crescentic subterminal markings of feathers on back, 

 scapulars, etc., heavier and darker, their terminal skirtings ashy rather than buffy; the 

 outer webs of two outer pairs of tail-feathers darker in tone, dusky rather than deep 

 pearl-gray; the lores white as to ground, but sharply and finely streaked with dusky. 

 Bill redder in tone basally. Length of adult: 355.6-431.8 (14. 00-17. 00) ; wing 254- 

 273.1 (10.00-10.75); ta il 165.1-215.9 (6.50-8.50); forked 101. 6-127 (4-00-5.00); bill 

 30.5 (1.20); depth at angle 5.9 (.23); tarsus 15.6 (.61). 



Recognition Marks. — Size of preceding; darker; tail more deeply forked, its 

 outer feathers gracefully streaming; bill pure carmine in spring, red to black in fall 

 migrations; smaller and slenderer than that of 5. hirundo. 



Nesting. — Does not breed in California. Nest and Eggs much as in S. hirundo, 

 but coloration of eggs averaging darker, deep olive-buff. Av. size 40.6 x 27.9 (1.60 

 x 1. 10). 



General Range. — Coasts of both hemispheres during migrations, summering 

 in the Northern Hemisphere, chiefly in the Arctic regions, but breeding, in North 

 America, from Maine (formerly Massachusetts) and northern British Columbia 

 northward; wintering chiefly in Antarctica, but also along both coasts of South America. 



Occurrence in California. — Fairly common migrant coastwise or well off 

 shore — observed only in the autumn. 



Authorities. — Lawrence {Sterna pikei), Ann. Lye. Nat. Hist. N. Y., vol. vi., 

 1853, p. 3 (Monterey); Beck, Proc. Calif. Acad. Sci., ser. 4, vol. iii., 1910, p. 64 (off 

 Monterey; migr.); Pierce, Condor, vol. xxi., 1919, p. 125 (Laguna Beach); C. W. Town- 

 send, in Bent, U. S. Nat. Mus., Bull. no. 113, 1921, p. 249 (life hist.; desc. and photos 

 of nest and eggs, etc.). 



H50 



