GULLS AND TERNS 23 



Monterey in winter and common down the coast to San Diego. In 

 the harbors they alight on tlie masts and fly about the vessels, often 

 following them thirty or forty miles from land. Their name probably 

 comes from the conmiotion they make at sight of a school of herring 

 or other little lish. As they follow the small fry about, the tishermeu 

 often take them for pilots and follow to get the larger tish which are 

 in pursuit of the little ones. 



52. Larus vegse (Palmen). Vega Gull. 



Like (iryentdtus, but mantle darker, deep pearl or plumbeous gray ; feet 

 pale flesh color. Size about as in aryentatus. 



Distribution. — ISouthern Europe and Central Asia to Japan and Bering- 

 Sea, and down the coast of North America in winter to California. 



Mr. Kobbe, in The Auk (xix. 19), after examining a large num- 

 ber of specimens, concludes that vega' and aryentatus are identical, 

 but as there is a difference of opinion as to its validity, the species 

 is included on what seems to be its only character, the slightly 

 darker mnntle. 



53. Larus californicus Lawr. California Gull. 



Adults. — Mantle clear bluish gray; outer primaries black, tipped with 

 white, the first two with subterminal white spots; a distinct gray wedge 

 on inner web of second ; bill yellow, with red and black spot near end 

 of lower mandible ; feet greenish. Youny : upper parts coarsely spotted 

 and uKjttled with dusky, buffy, grayish, and whitish ; under parts mottled 

 and streaked ; quills and tail blackish ; bill dusky, with black tip. Lenyt/i : 

 20-2:), ^\u^g: ir,.00-l<).T."), bill l.()5-2.15, depth of 'bill at angle .G0-.7-'). 



Distribution . — Western North America from Alaska to Mexico, chiefly 

 in the interior. ^ 



Mr. Loomis says that in the matter of numbers near Monterey in 

 midwinter the California gull ranks with its larger congeners the 

 glaucous-winged and the western. Mr. Grinnell finds it common 

 along the southern coast, wdiere it frequents the fresh-water marshes, 

 and he has seen it on the Los Angeles river- bottoms. At Pescadero 

 in the low fields near the ocean liundreds have been seen following 

 the plough. 



54. Larus delawarensis On/. Rinc-billed Gull. 



Adults. — Mantb; light pearl gray ; bill greenish yellow, crossed near end 

 by a distinct ])hu'k band, tip yellow or orange ; eyelids vermilion, iris pale 

 yellow; feet i>alt' yellow, sonu'times tinged with greenish. Youny: upper 

 parts dusky, feathers bordered and marked with grayish buff or whitish ; 

 under ])arts white. si)otted along- sides witli grayisli l)r(>wn ; (inills blackish, 

 tli«' sliortcr ones grav at base and ti])ped with wliite ; base of tail gray, 

 outer half lilackisli.'tipi)ed with white. Ltuqth: IS-'JO, wing- lo.^O-l'i.T-"), 

 bill l.-M-I.T."). deptli at angle of lower mandii)le ^O-.iSTy. 



Distribution. — Whole of North America, breeding as far south as 

 Colorado, but mainly north of the United States ; migrating south to Cuba 

 and Mexit'o. 



Ni'St. — On the ground, made of dry grass. Kyys : usually ".. 



