BIRDS OF PENNSYLVANIA. 13 



these birds have a habit of uttering loud, wailing- cries, interspersed with 

 harsh shrieks, which are among the most peculiar notes heard in the 

 northern breeding grounds. At all times the Jaegers are given to wan- 

 dering, and one is likely to find them almost anywhere along the coast. 

 They are not infrequently seen harrying terns or gulls to make them dis- 

 gorge fish just caught. If successful they dart down and, rising under the 

 falling morsel, catch it in their capacious mouth. This robbery is often 

 performed by two birds in unison, but whether the birds alternate in 

 disposing of the spoil or not could not be learned. * * * * They 

 are very greedy, and frequently swallow so much that they are unable 

 to fly until a portion is disgorged." 



FAMILY LARUXflS. GULLS AND TERNS. 



SUBFAMILY LARIN^l. GULLS. 



THE GULLS. 



Only two or three species of this group, represented by over twenty-five species 

 and subspecies in North America, have been observed by naturalists to occur in 

 Pennsylvania with any degree of regularity. None breed in this commonwealth 

 where they are found only as transitory sojourners during the spring, fall and win- 

 ter months. Gulls vary greatly in size ; some are classed among the largest of the 

 marine birds, while others are but little larger than their near relatives the terns. 

 In these birds the body is more robust than in the terns, the bill is hooked, the tail 

 is generally even and the toes are fully webbed. 



They are light, easy and graceful swimmers, but are unable to dive, though some 

 of them secure their food by plunging for it in the same manner as terns. The 

 sexes are similar in color, and the female is usually a trifle smaller than the male. 

 Gulls differs, greatly in their plumage, but the adults are usually white with a dark, 

 or bluish-gray mantle ; in some species the head especially in the breeding season 

 is enveloped in a dark hood. The young are wholly different from the old birds, 

 being much darker and usually more or less spotted or mottled with gray and dif- 

 ferent shades of brown. Gulls generally associate in large flocks, not only when 

 breeding but also during the spring and fall migrations, and in winter. They in- 

 habit chiefly the sea-coasts and large inland waters ; some kinds, however, and es- 

 pecially the smaller species when migrating, and also frequently in winter, ascend 

 to a considerable distance many of the principal rivers emptying in the bays and 

 ocean. 



Gulls are gluttonous and voracious, feeding on almost any kind of animal sub- 

 stances, fish, however, is their main article of diet. These birds, with a few excep- 

 tions, breed beyond the northern limits cff the United States, and most of them re- 

 tire during the season of reproduction to the arctic regions. The nest is usually 

 built on the ground or near it, some species construct rude nests of twigs, grasses, 

 moss, etc., while others, it is said, deposit their eggs either on the bare ground or on 

 rocky ledges. The eggs, two to four in number, are variously spotted with different 

 shades of black, brown and gray. 



The loud, shrill arid unmusical notes of these birds are most frequently heard 

 when they are on the wing ; they are, also, especially noisy when feeding, or when 

 their nesting places are approached. The flesh of the old bird, particularly that of 

 the larger species, is quite tough and unpalatable. The flesh of the young birds, 

 especially the smaller kinds, is sometimes eaten by fishermen and hunters. Al- 

 though the gulls are seldom used for food, unless it is by the Eskimo and other 

 residents of the northern regions, who, it is stated, esteem the flesh of several species 

 as great delicacies it is a noteworthy fact that the silvery and downy feathers of 

 these birds are largely used by our milliners. 



