THE FORSTER'S TERN. 



{Sterna forsteri.) 



The range of Forster's Tern may be 

 considered as covering North America 

 in general, "breeding from Manitoba 

 southward to \'irginia, IlHnois, Texas 

 and CaUfornia." in winter it passes 

 southward into Central America and to 

 Brazil. It is the common Tern of the 

 ^Mississippi \'alley and is quite abundant 

 on the larger inland waters as far north 

 as ^Manitoba. It is far from common 

 along the Atlantic coast excepting at 

 Cobb's Island, Virginia, where it breeds 

 in numbers, though the individuals of 

 this species were not as numerous as 

 were those of the common or Wilson's 

 Tern. 



In appearance as w^ell as in its habits, 

 Forster's Tern resembles the common 

 tern (Sterna hirundo). The two species 

 may, however, be distinguished by the 

 color of the outer tail feathers; those of 

 Forster's Tern having the inner webs 

 darker colored than the outer webs, while 

 the reverse is characteristic of the same 

 feathers in the common tern. The two 

 species may also be distinguished when 

 on the wing by the peculiar grating note 

 of the Forster's Tern, the sound of 

 which has been likened by Dr. Ridgway 

 to the "sonorous qna-a-a of the logger- 

 head shrike." 



Forster's Tern breeds in colonies and 

 also in company with other terns and 

 with gulls. Its nest, of flags and various 

 water plants, is usually built in grassy 

 marshes. The old birds are very watch- 

 ful and carefully guard their nests, eggs 

 and offspring. When disturbed at their 

 nests, they become very noisy, 'uttering 

 a grating, monotonous note." It is said 

 that at times, in their frenzy, they flv at 

 an intruder, often approaching very 

 close to his head. 



Mr. E. W. Xelson describes n^sts of 

 the Forster's Tern that he found in 

 Northern Illinois as having a base two 

 feet or more in diameter and the greatest 

 depth as about eight inches. He also 

 g'i\e£ the following excellent record of 

 lis habits : "While iiear the nests the 

 birds were circling high, overhead, now 

 and then uttering a harsh cry, but con- 

 cealing myself in the rice nearby, 1 soon 

 secured several of the pare^it birds as 

 chey flew about the nests uttering their 

 angry cries at the spoliation of their 

 treasures. After the first bird fell into 

 the water, the others show«:<; the usual 

 syriipathy of their kind, but as the third 

 or fourth specimen was killed, the re- 

 mainder cautiously withdrew and uttered 

 their complaints at a safer aistance." 



In the winter, the plumage of this 

 bee^utiful tern shows a decided change. 

 The head becomes white, more or less 

 spotted with black ; the eye is enclosed 

 by a large black area; the bill becomes 

 black and the feet brownish. The tail 

 also is not as deeply forked as it is dur- 

 ing the summer plumage. 



Forster's Tern is quite often called 

 Sea Swallow, though this term is more 

 appropriately applied to the common or 

 Wilson's tern. The terns, with swallow- 

 like tails, slender outlines and graceful 

 flight, are even more beautiful than their 

 relatives, the gulls. Mr. Chapman has 

 said : "Like the gulls, they seem so in 

 harmony with their surroundings that 

 no coast view is perfect from which the 

 terns are missing. They add the requi- 

 site touch of life, and make still more 

 impressive the thunder of the surf dash- 

 ing over rocks or curling in long, comb- 

 ing waves on the beach." 



