THE RING-BILLED GULL. 551 



and the nature of their aerial progress quite baffles, at times, human com- 

 prehension. I once studied a very tame flock of Gulls, of an allied species, 

 as it followed a Puget Sound steamer ; and I am able to testify that the birds 

 moved about upon the air at will, and for indefinite periods of time, without 

 the slightest semblance of wing-beats. At one time when we were facing a 

 stirBsh breeze and making headway against it at the rate of about fifteen miles 

 an hour, the Gulls were resting in midair above the afterdeck. One bird 

 in particular, remained for about five minutes within four feet of my out- 

 stretched hand. Without a visible sign of propulsion the bird moved forward 

 upon the air as by some inner compulsion, at an approximate rate of thirty 

 miles per hour; and when the Gull shifted its position, it was to pass forward 

 and upward rapidly -without wing-beats. By what magical resolution of 

 forces the birds are thus able to make the wind contradict itself one may not 

 even conjecture. 



The sagacity of this bird is further shown in the fact that it has largely 

 abandoned its costly habit of nesting upon the ground, the prey of every 

 pirate, and has taken to building in the tops of evergreen trees. To be sure 

 the tree-tops along the coast of Maine, Nova Scotia, and Labrador are not 

 quite inaccessible, but fishermen no longer gather gulls' eggs by the bushel 

 basketful as once they did. 



No. 263. 



RING-BILLED GULL. 



A. O. U. No. 54. Larus delawarensis Ord. 



Description. Adult in summer: Mantle deep pearl-gray (typical "Gull- 

 blue", much as in L. argentatus} ; primaries mostly black, the color decreasing in 

 extent inwardly, and disappearing with the sixth quill, owing to encroachment 

 of basal white (or pearl-gray) ; the first quill with subterminal white spot, the 

 third to sixth tipped with white (that of the third to fifth often lacking in worn 

 plumages) ; remaining plumage white; bill greenish yellow, crossed at angle by 

 a broad and clearly defined black band ; feet light yellow or greenish ; eyelids 

 vermilion ; iris pale yellow. Adult in winter : Similar, but head and hind-neck 

 streaked with dusky gray. Young : Above, brownish dusky or fuscous, edged 

 and varied by whitish and grayish buff ; outer primaries plain blackish, the shorter 

 ones extensively bluish gray, and tipped with white; tail light bluish gray more 

 or less mottled with blackish ; crossed by a broad subterminal black band and 

 tipped with white ; below white, the sides spotted with brownish gray ; bill blackish, 

 paling basally. Length 18.00-20.00 (457.2-508.) ; wing 14.50 (368.3) ; tail 6.00 

 (152.4) ; bill i. 60 (40.6) ; tarsus 2.20 (55.9). 



Recognition Marks. Crow size, but appearing larger ; mantle "gull-blue" : 

 primaries blackish ; black band across bill at angle distinctive. 



