LIFE HISTOIUES OF NORTH AMERICAN GULLS AND TERNS. 291 



reeds, and the constant din of their rhythmic notes gave volume to 

 the grand chorus of varied voices that were ringing in our ears. And 

 last but not least, among all this great concourse of bird life, was 

 the subject of this sketch, the black tern, flitting hither and thither, 

 one of the most active and the most restless of the throng. 



Nesting. — Among all the water birds of the middle west I suppose 

 the black tern is the most widely distributed, the most universally 

 common and the most characteristic summer resident of the sloughs, 

 marshes, and wet meadows of the plains. The center of its abun- 

 dance seems to be in the great, flat marsh country of Manitoba, where 

 we found it everywhere the commonest and most conspicuous water 

 bird in the extensive cane swamps about Lake Winnipegosis and 

 Waterhen Lake, breeding anywhere in wet marshy situations. In 

 the tall, thick growth of canes {Fhragmites com^nunis) their nests 

 were widely scattered and hard to find, but wherever the canes were 

 beaten down or partially open they had placed their frail nests on 

 the dead and fallen canes of the previous year's growth, and about 

 the little open marshy ponds we found them nesting in small colonies. 

 If we did not find the nests it was not through any fault of the terns, 

 for they did the best they could to show us by their actions where 

 their treasures were hidden. There are few birds that are bolder, 

 more solicitous or more aggressive than these little terns in the de- 

 fense of their eggs, and even before the eggs are laid they will indi- 

 cate by their actions the exact locality they have chosen. The short, 

 sharp notes of protest come thicker and faster, as the intruder ap- 

 proaches, and when he is fairly among them their cries are prolonged 

 into hard, shrill, angry screams, as the excited terns dart down upon 

 his head, striking him again and again if he does not retreat. By 

 making use of this telltale habit we were able to locate a number of 

 nests in the hidden recesses of the tall canes, where they were suffi- 

 ciently open for the bird to drop down upon the nest from above or 

 to rise from it without becoming entangled in the canes. Some of 

 these nests were quite elaborate and well made, resembling miniature 

 nests of Forster's terns or Franklin's gulls, but more often they con- 

 sisted of a few pieces of dead canes or reeds loosely arranged, and 

 sometimes the eggs were laid in a mere depression in the prostrate 

 and closely matted vegetation. In one little open slough hole we 

 found four nests within a radius of 5 yards, but this is closer than 

 they are usually placed. One of these was on the edge of a large 

 muskrat house, just above the water level, and another was built on 

 the remains of an old submerged muskrat nest. 



In North Dakota in 1901 we found small colonies of black terns 

 nesting in open situations in the sloughs, where the water was 1 

 or 2 feet deep and where numerous little piles of dead and par- 



