BIRDS OF PENNSYLVANIA. 17 



" Young. The head is white, marked on the hind headand neck with bluish-gray; 

 a spot of the same color over the ears ; a narrow crescent of black in front of the eye ; 

 wings and shoulders marked with black; primaries, black ; tail, white, with a sub- 

 terminal black band; bill, black; rest of the plumage same as in adult" Baird's 

 Birds of N. A. Length about 17| inches ; extent about 35 inches. 



Habitat. Arctic regions, south in eastern North America in winter to the great 

 lakes and the Middle States. 



Accidental winter visitant. About ten years ago the late Henry B. 

 Graves, of Berks county, mounted a young Kittiwake, which had been 

 captured near Lancaster city in midwinter. Mr. Joseph Krider, of 

 Philadelphia, has in his collection one of these birds which was shot 

 several years ago near Philadelphia by the late John Krider. Dr. A. C. 

 Treichler, of Elizabethtown, mentions this species as a straggler in 

 Lancaster county, Pa. The Kittiwake is a common bird in the arctic 

 regions, and in winter this species wanders irregularly southward along 

 the Atlantic coast as far as New Jersey, where it is quite rare. 



SUBFAMILY STERNIN^B. TERNS. 

 THE TERNS. 



While these birds are most abundant on the seacoast, neighboring bays and inlets, 

 they are not exclusively maritime ; many frequent, during migrations, inland 

 waters (large lakes commonly) where some also remain during the summer to rear 

 their young. None of the Terns are known to breed in Pennsylvania. Although 

 quite a number of these birds known commonly about the seashore as "Sea 

 Swallows" have been taken by various naturalists and collectors, in this state, 

 during migrations, none, according to my observations, can be said to occur through- 

 out this comm'onwealth as regular or common spring and fall migrants. Several 

 species are common on the coast of New Jersey during migrations, and some are 

 also found there as summer residents. Almost every year, in the spring, late sum- 

 mer and in the autumn, after severe stormy weather, Terns of different kind are 

 frequently noticed about the rivers, lakes and ponds in the interior, principally, 

 however, in the eastern sections of the state. These birds, it would appear, have 

 been, by force of the elements rather than their own inclinations, compelled to leave, 

 temporarily, their chosen haunts in the vicinity of the ocean. 



At Lake Erie, some species of this subfamily are found as common migrants ; in 

 the harbor at Erie city two or three species are more or less common every spring 

 and fall. This is the only section in Pennsylvania, so far as I have been able to 

 learn, where Terns are seen with any degree of certainty during migrations. Terns, 

 with a few exceptions, are much smaller than Gulls, from which they differ also in 

 having straight, slender, sharp-pointed bills, and, mostly, conspicuously forked 

 tails. The sexes are quite similar in size and color, but the young and old birds in 

 fall and winter show great variations in coloration ; wings long, narrow and pointed ; 

 the flight is buoyant and graceful. They seem to be almost continually on the wing, 

 and sometimes are seen out at sea many miles from land. Terns are unable to dive ; 

 their feet are webbed, but they are scarcely ever seen on the water ; it is said they 

 never swim from choice. These birds walk but little, though they often alight on 

 the beach, sand-bars and rocks. Terns, especially the larger kinds, subsist princi- 

 pally on little fish ; some of the smaller species, in addition to small fish, feed to 

 some extent on insects. When in quest of prey they frequently make extensive circuits 

 over the ocean, bays, brackish ponds and marshy places ; in flying over the water, 

 searching for food, they invariably are seen with the bill pointing straight down- 

 ward ; this, as Dr. Coues writes, " makes them look like colossal mosquitoes." They 



2 BIRDS. 



