662 BONAPARTE’S GULL. 
south as San Pedro in California, as well as many of the inland 
waters of the United States, while on the east side it is abundant and 
of regular occurrence down to South Carolina, and occasionally visits 
the Bermudas ; it is, however, rare on the Gulf side of Florida, and, 
except as a wanderer to the Bahamas, has not yet been obtained in 
the Antilles. With the first genial weather in April and through- 
out the greater part of May a succession of birds passes northward ; 
the earlier ones being adults, while the later arrivals are birds of the 
previous year, some of which linger on the coast-marshes all the 
summer. Richardson, who found this species breeding in the 
vicinity of Great Bear Lake, says that it is seen there as soon as the 
first pools are thawed, and before the ground is denuded of snow. 
The above explorer, as well as Messrs. R. MacFarlane, Kennicott 
and others, state that Bonaparte’s Gull builds in colonies, placing 
its nest, which is composed of sticks, grass, moss &c., on the 
branches of some bush or tree—often a spruce-fir—at elevations 
varying from four to twenty feet; in some districts, however, it 
appears to breed in marshes, and, presumably, on the ground. The 
eggs, 2-3 in number, are dull olive-colour, spotted, scrolled and 
zoned with brown: measurements 1°9 by 1°4 in., though there is 
considerable variation in a large series. ‘This species undoubtedly 
alights upon trees. The food consists of small fish, crustaceans, 
insects and their larve; the flight is buoyant and Tern-like; and 
the note is described as a “sharp but rather faint squeak.” 
The adult in summer has the hood slate-black ; mantle pearl-grey ; 
tail and under-parts white ; first primary white, except on the outer 
web and across the tip, where it is black; the other quills subfer- 
minally barred with black, and white or greyish on the inner webs ; 
bill black ; legs and feet orange-red. The sexes are alike in plumage, 
and the statements of Audubon and Bonaparte that the female has 
a brown hood are as inexplicable as they are erroneous. In winter 
the head is nearly white. The bird figured on the rock is an im- 
mature specimen in its first winter. The transitional stages are 
similar to those in other Gulls; but at all ages this species may be 
distinguished by the white margins to the inner webs of the two 
outer primaries. Length 14 in.; wing 10°25 in. y 
The American Laughing Gull, Z. a¢ricilla, was added to the 
British list by Montagu, in error, as indicated by his description 
of the bird obtained at Winchelsea. This species is stouter than 
our L. ridibundus, has a blacker hood and darker mantle, and may 
always be distinguished by its black outer primaries. 
